zf

connection.ex (51604B)

---

 if Code.ensure_loaded?(Postgrex) do
   defmodule Ecto.Adapters.Postgres.Connection do
     @moduledoc false
 
     @default_port 5432
     @behaviour Ecto.Adapters.SQL.Connection
 
     ## Module and Options
 
     @impl true
     def child_spec(opts) do
       opts
       |> Keyword.put_new(:port, @default_port)
       |> Postgrex.child_spec()
     end
 
     @impl true
     def to_constraints(%Postgrex.Error{postgres: %{code: :unique_violation, constraint: constraint}}, _opts),
       do: [unique: constraint]
     def to_constraints(%Postgrex.Error{postgres: %{code: :foreign_key_violation, constraint: constraint}}, _opts),
       do: [foreign_key: constraint]
     def to_constraints(%Postgrex.Error{postgres: %{code: :exclusion_violation, constraint: constraint}}, _opts),
       do: [exclusion: constraint]
     def to_constraints(%Postgrex.Error{postgres: %{code: :check_violation, constraint: constraint}}, _opts),
       do: [check: constraint]
 
     # Postgres 9.2 and earlier does not provide the constraint field
     @impl true
     def to_constraints(%Postgrex.Error{postgres: %{code: :unique_violation, message: message}}, _opts) do
       case :binary.split(message, " unique constraint ") do
         [_, quoted] -> [unique: strip_quotes(quoted)]
         _ -> []
       end
     end
     def to_constraints(%Postgrex.Error{postgres: %{code: :foreign_key_violation, message: message}}, _opts) do
       case :binary.split(message, " foreign key constraint ") do
         [_, quoted] ->
           [quoted | _] = :binary.split(quoted, " on table ")
           [foreign_key: strip_quotes(quoted)]
         _ ->
           []
       end
     end
     def to_constraints(%Postgrex.Error{postgres: %{code: :exclusion_violation, message: message}}, _opts) do
       case :binary.split(message, " exclusion constraint ") do
         [_, quoted] -> [exclusion: strip_quotes(quoted)]
         _ -> []
       end
     end
     def to_constraints(%Postgrex.Error{postgres: %{code: :check_violation, message: message}}, _opts) do
       case :binary.split(message, " check constraint ") do
         [_, quoted] -> [check: strip_quotes(quoted)]
         _ -> []
       end
     end
 
     def to_constraints(_, _opts),
       do: []
 
     defp strip_quotes(quoted) do
       size = byte_size(quoted) - 2
       <<_, unquoted::binary-size(size), _>> = quoted
       unquoted
     end
 
     ## Query
 
     @impl true
     def prepare_execute(conn, name, sql, params, opts) do
       case Postgrex.prepare_execute(conn, name, sql, params, opts) do
         {:error, %Postgrex.Error{postgres: %{pg_code: "22P02", message: message}} = error} ->
           context = """
           . If you are trying to query a JSON field, the parameter may need to be interpolated. \
           Instead of
 
               p.json["field"] != "value"
 
           do
 
               p.json["field"] != ^"value"
           """
 
           {:error, put_in(error.postgres.message, message <> context)}
         other ->
           other
         end
 
     end
 
     @impl true
     def query(conn, sql, params, opts) do
       Postgrex.query(conn, sql, params, opts)
     end
 
     @impl true
     def query_many(_conn, _sql, _params, _opts) do
       raise RuntimeError, "query_many is not supported in the Postgrex adapter"
     end
 
     @impl true
     def execute(conn, %{ref: ref} = query, params, opts) do
       case Postgrex.execute(conn, query, params, opts) do
         {:ok, %{ref: ^ref}, result} ->
           {:ok, result}
 
         {:ok, _, _} = ok ->
           ok
 
         {:error, %Postgrex.QueryError{} = err} ->
           {:reset, err}
 
         {:error, %Postgrex.Error{postgres: %{code: :feature_not_supported}} = err} ->
           {:reset, err}
 
         {:error, _} = error ->
           error
       end
     end
 
     @impl true
     def stream(conn, sql, params, opts) do
       Postgrex.stream(conn, sql, params, opts)
     end
 
     @parent_as __MODULE__
     alias Ecto.Query.{BooleanExpr, JoinExpr, QueryExpr, WithExpr}
 
     @impl true
     def all(query, as_prefix \\ []) do
       sources = create_names(query, as_prefix)
       {select_distinct, order_by_distinct} = distinct(query.distinct, sources, query)
 
       cte = cte(query, sources)
       from = from(query, sources)
       select = select(query, select_distinct, sources)
       join = join(query, sources)
       where = where(query, sources)
       group_by = group_by(query, sources)
       having = having(query, sources)
       window = window(query, sources)
       combinations = combinations(query)
       order_by = order_by(query, order_by_distinct, sources)
       limit = limit(query, sources)
       offset = offset(query, sources)
       lock = lock(query, sources)
 
       [cte, select, from, join, where, group_by, having, window, combinations, order_by, limit, offset | lock]
     end
 
     @impl true
     def update_all(%{from: %{source: source}} = query, prefix \\ nil) do
       sources = create_names(query, [])
       cte = cte(query, sources)
       {from, name} = get_source(query, sources, 0, source)
 
       prefix = prefix || ["UPDATE ", from, " AS ", name | " SET "]
       fields = update_fields(query, sources)
       {join, wheres} = using_join(query, :update_all, "FROM", sources)
       where = where(%{query | wheres: wheres ++ query.wheres}, sources)
 
       [cte, prefix, fields, join, where | returning(query, sources)]
     end
 
     @impl true
     def delete_all(%{from: from} = query) do
       sources = create_names(query, [])
       cte = cte(query, sources)
       {from, name} = get_source(query, sources, 0, from)
 
       {join, wheres} = using_join(query, :delete_all, "USING", sources)
       where = where(%{query | wheres: wheres ++ query.wheres}, sources)
 
       [cte, "DELETE FROM ", from, " AS ", name, join, where | returning(query, sources)]
     end
 
     @impl true
     def insert(prefix, table, header, rows, on_conflict, returning, placeholders) do
       counter_offset = length(placeholders) + 1
       values =
         if header == [] do
           [" VALUES " | intersperse_map(rows, ?,, fn _ -> "(DEFAULT)" end)]
         else
           [" (", quote_names(header), ") " | insert_all(rows, counter_offset)]
         end
 
       ["INSERT INTO ", quote_table(prefix, table), insert_as(on_conflict),
        values, on_conflict(on_conflict, header) | returning(returning)]
     end
 
     defp insert_as({%{sources: sources}, _, _}) do
       {_expr, name, _schema} = create_name(sources, 0, [])
       [" AS " | name]
     end
     defp insert_as({_, _, _}) do
       []
     end
 
     defp on_conflict({:raise, _, []}, _header),
       do: []
     defp on_conflict({:nothing, _, targets}, _header),
       do: [" ON CONFLICT ", conflict_target(targets) | "DO NOTHING"]
     defp on_conflict({fields, _, targets}, _header) when is_list(fields),
       do: [" ON CONFLICT ", conflict_target!(targets), "DO " | replace(fields)]
     defp on_conflict({query, _, targets}, _header),
       do: [" ON CONFLICT ", conflict_target!(targets), "DO " | update_all(query, "UPDATE SET ")]
 
     defp conflict_target!([]),
       do: error!(nil, "the :conflict_target option is required on upserts by PostgreSQL")
     defp conflict_target!(target),
       do: conflict_target(target)
 
     defp conflict_target({:unsafe_fragment, fragment}),
       do: [fragment, ?\s]
     defp conflict_target([]),
       do: []
     defp conflict_target(targets),
       do: [?(, quote_names(targets), ?), ?\s]
 
     defp replace(fields) do
       ["UPDATE SET " |
        intersperse_map(fields, ?,, fn field ->
          quoted = quote_name(field)
          [quoted, " = ", "EXCLUDED." | quoted]
        end)]
     end
 
     defp insert_all(query = %Ecto.Query{}, _counter) do
       [?(, all(query), ?)]
     end
 
     defp insert_all(rows, counter) do
       ["VALUES ", intersperse_reduce(rows, ?,, counter, fn row, counter ->
         {row, counter} = insert_each(row, counter)
         {[?(, row, ?)], counter}
       end)
       |> elem(0)]
     end
 
     defp insert_each(values, counter) do
       intersperse_reduce(values, ?,, counter, fn
         nil, counter ->
           {"DEFAULT", counter}
 
         {%Ecto.Query{} = query, params_counter}, counter ->
           {[?(, all(query), ?)], counter + params_counter}
 
         {:placeholder, placeholder_index}, counter ->
           {[?$ | placeholder_index], counter}
 
         _, counter ->
           {[?$ | Integer.to_string(counter)], counter + 1}
       end)
     end
 
     @impl true
     def update(prefix, table, fields, filters, returning) do
       {fields, count} = intersperse_reduce(fields, ", ", 1, fn field, acc ->
         {[quote_name(field), " = $" | Integer.to_string(acc)], acc + 1}
       end)
 
       {filters, _count} = intersperse_reduce(filters, " AND ", count, fn
         {field, nil}, acc ->
           {[quote_name(field), " IS NULL"], acc}
 
         {field, _value}, acc ->
           {[quote_name(field), " = $" | Integer.to_string(acc)], acc + 1}
       end)
 
       ["UPDATE ", quote_table(prefix, table), " SET ",
        fields, " WHERE ", filters | returning(returning)]
     end
 
     @impl true
     def delete(prefix, table, filters, returning) do
       {filters, _} = intersperse_reduce(filters, " AND ", 1, fn
         {field, nil}, acc ->
           {[quote_name(field), " IS NULL"], acc}
 
         {field, _value}, acc ->
           {[quote_name(field), " = $" | Integer.to_string(acc)], acc + 1}
       end)
 
       ["DELETE FROM ", quote_table(prefix, table), " WHERE ", filters | returning(returning)]
     end
 
     @impl true
     def explain_query(conn, query, params, opts) do
       {explain_opts, opts} =
         Keyword.split(opts, ~w[analyze verbose costs settings buffers timing summary format]a)
 
       map_format? = {:format, :map} in explain_opts
 
       case query(conn, build_explain_query(query, explain_opts), params, opts) do
         {:ok, %Postgrex.Result{rows: rows}} when map_format? ->
           {:ok, List.flatten(rows)}
         {:ok, %Postgrex.Result{rows: rows}} ->
           {:ok, Enum.map_join(rows, "\n", & &1)}
         error -> error
       end
     end
 
     def build_explain_query(query, []) do
       ["EXPLAIN ", query]
       |> IO.iodata_to_binary()
     end
 
     def build_explain_query(query, opts) do
       {analyze, opts} = Keyword.pop(opts, :analyze)
       {verbose, opts} = Keyword.pop(opts, :verbose)
 
       # Given only ANALYZE or VERBOSE opts we assume the legacy format
       # to support all Postgres versions, otherwise assume the new
       # syntax supported since v9.0
       case opts do
         [] ->
           [
             "EXPLAIN ",
             if_do(quote_boolean(analyze) == "TRUE", "ANALYZE "),
             if_do(quote_boolean(verbose) == "TRUE", "VERBOSE "),
             query
           ]
 
         opts ->
           opts =
             ([analyze: analyze, verbose: verbose] ++ opts)
             |> Enum.reduce([], fn
               {_, nil}, acc ->
                 acc
 
               {:format, value}, acc ->
                 [String.upcase("#{format_to_sql(value)}") | acc]
 
               {opt, value}, acc ->
                 [String.upcase("#{opt} #{quote_boolean(value)}") | acc]
             end)
             |> Enum.reverse()
             |> Enum.join(", ")
 
           ["EXPLAIN ( ", opts, " ) ", query]
       end
       |> IO.iodata_to_binary()
     end
 
     ## Query generation
 
     binary_ops =
       [==: " = ", !=: " != ", <=: " <= ", >=: " >= ", <: " < ", >: " > ",
        +: " + ", -: " - ", *: " * ", /: " / ",
        and: " AND ", or: " OR ", ilike: " ILIKE ", like: " LIKE "]
 
     @binary_ops Keyword.keys(binary_ops)
 
     Enum.map(binary_ops, fn {op, str} ->
       defp handle_call(unquote(op), 2), do: {:binary_op, unquote(str)}
     end)
 
     defp handle_call(fun, _arity), do: {:fun, Atom.to_string(fun)}
 
     defp select(%{select: %{fields: fields}} = query, select_distinct, sources) do
       ["SELECT", select_distinct, ?\s | select_fields(fields, sources, query)]
     end
 
     defp select_fields([], _sources, _query),
       do: "TRUE"
     defp select_fields(fields, sources, query) do
       intersperse_map(fields, ", ", fn
         {:&, _, [idx]} ->
           case elem(sources, idx) do
             {nil, source, nil} ->
               error!(query, "PostgreSQL adapter does not support selecting all fields from fragment #{source}. " <>
                             "Please specify exactly which fields you want to select")
             {source, _, nil} ->
               error!(query, "PostgreSQL adapter does not support selecting all fields from #{source} without a schema. " <>
                             "Please specify a schema or specify exactly which fields you want to select")
             {_, source, _} ->
               source
           end
         {key, value} ->
           [expr(value, sources, query), " AS " | quote_name(key)]
         value ->
           expr(value, sources, query)
       end)
     end
 
     defp distinct(nil, _, _), do: {[], []}
     defp distinct(%QueryExpr{expr: []}, _, _), do: {[], []}
     defp distinct(%QueryExpr{expr: true}, _, _), do: {" DISTINCT", []}
     defp distinct(%QueryExpr{expr: false}, _, _), do: {[], []}
     defp distinct(%QueryExpr{expr: exprs}, sources, query) do
       {[" DISTINCT ON (",
         intersperse_map(exprs, ", ", fn {_, expr} -> expr(expr, sources, query) end), ?)],
        exprs}
     end
 
     defp from(%{from: %{hints: [_ | _]}} = query, _sources) do
       error!(query, "table hints are not supported by PostgreSQL")
     end
 
     defp from(%{from: %{source: source}} = query, sources) do
       {from, name} = get_source(query, sources, 0, source)
       [" FROM ", from, " AS " | name]
     end
 
     defp cte(%{with_ctes: %WithExpr{recursive: recursive, queries: [_ | _] = queries}} = query, sources) do
       recursive_opt = if recursive, do: "RECURSIVE ", else: ""
       ctes = intersperse_map(queries, ", ", &cte_expr(&1, sources, query))
       ["WITH ", recursive_opt, ctes, " "]
     end
 
     defp cte(%{with_ctes: _}, _), do: []
 
     defp cte_expr({name, cte}, sources, query) do
       [quote_name(name), " AS ", cte_query(cte, sources, query)]
     end
 
     defp cte_query(%Ecto.Query{} = query, sources, parent_query) do
       query = put_in(query.aliases[@parent_as], {parent_query, sources})
       ["(", all(query, subquery_as_prefix(sources)), ")"]
     end
 
     defp cte_query(%QueryExpr{expr: expr}, sources, query) do
       expr(expr, sources, query)
     end
 
     defp update_fields(%{updates: updates} = query, sources) do
       for(%{expr: expr} <- updates,
           {op, kw} <- expr,
           {key, value} <- kw,
           do: update_op(op, key, value, sources, query)) |> Enum.intersperse(", ")
     end
 
     defp update_op(:set, key, value, sources, query) do
       [quote_name(key), " = " | expr(value, sources, query)]
     end
 
     defp update_op(:inc, key, value, sources, query) do
       [quote_name(key), " = ", quote_qualified_name(key, sources, 0), " + " |
        expr(value, sources, query)]
     end
 
     defp update_op(:push, key, value, sources, query) do
       [quote_name(key), " = array_append(", quote_qualified_name(key, sources, 0),
        ", ", expr(value, sources, query), ?)]
     end
 
     defp update_op(:pull, key, value, sources, query) do
       [quote_name(key), " = array_remove(", quote_qualified_name(key, sources, 0),
        ", ", expr(value, sources, query), ?)]
     end
 
     defp update_op(command, _key, _value, _sources, query) do
       error!(query, "unknown update operation #{inspect command} for PostgreSQL")
     end
 
     defp using_join(%{joins: []}, _kind, _prefix, _sources), do: {[], []}
     defp using_join(%{joins: joins} = query, kind, prefix, sources) do
       froms =
         intersperse_map(joins, ", ", fn
           %JoinExpr{qual: :inner, ix: ix, source: source} ->
             {join, name} = get_source(query, sources, ix, source)
             [join, " AS " | name]
           %JoinExpr{qual: qual} ->
             error!(query, "PostgreSQL supports only inner joins on #{kind}, got: `#{qual}`")
         end)
 
       wheres =
         for %JoinExpr{on: %QueryExpr{expr: value} = expr} <- joins,
             value != true,
             do: expr |> Map.put(:__struct__, BooleanExpr) |> Map.put(:op, :and)
 
       {[?\s, prefix, ?\s | froms], wheres}
     end
 
     defp join(%{joins: []}, _sources), do: []
     defp join(%{joins: joins} = query, sources) do
       [?\s | intersperse_map(joins, ?\s, fn
         %JoinExpr{on: %QueryExpr{expr: expr}, qual: qual, ix: ix, source: source, hints: hints} ->
           if hints != [] do
             error!(query, "table hints are not supported by PostgreSQL")
           end
 
           {join, name} = get_source(query, sources, ix, source)
           [join_qual(qual), join, " AS ", name | join_on(qual, expr, sources, query)]
       end)]
     end
 
     defp join_on(:cross, true, _sources, _query), do: []
     defp join_on(_qual, expr, sources, query), do: [" ON " | expr(expr, sources, query)]
 
     defp join_qual(:inner), do: "INNER JOIN "
     defp join_qual(:inner_lateral), do: "INNER JOIN LATERAL "
     defp join_qual(:left),  do: "LEFT OUTER JOIN "
     defp join_qual(:left_lateral),  do: "LEFT OUTER JOIN LATERAL "
     defp join_qual(:right), do: "RIGHT OUTER JOIN "
     defp join_qual(:full),  do: "FULL OUTER JOIN "
     defp join_qual(:cross), do: "CROSS JOIN "
 
     defp where(%{wheres: wheres} = query, sources) do
       boolean(" WHERE ", wheres, sources, query)
     end
 
     defp having(%{havings: havings} = query, sources) do
       boolean(" HAVING ", havings, sources, query)
     end
 
     defp group_by(%{group_bys: []}, _sources), do: []
     defp group_by(%{group_bys: group_bys} = query, sources) do
       [" GROUP BY " |
        intersperse_map(group_bys, ", ", fn
          %QueryExpr{expr: expr} ->
            intersperse_map(expr, ", ", &expr(&1, sources, query))
        end)]
     end
 
     defp window(%{windows: []}, _sources), do: []
     defp window(%{windows: windows} = query, sources) do
       [" WINDOW " |
        intersperse_map(windows, ", ", fn {name, %{expr: kw}} ->
          [quote_name(name), " AS " | window_exprs(kw, sources, query)]
        end)]
     end
 
     defp window_exprs(kw, sources, query) do
       [?(, intersperse_map(kw, ?\s, &window_expr(&1, sources, query)), ?)]
     end
 
     defp window_expr({:partition_by, fields}, sources, query) do
       ["PARTITION BY " | intersperse_map(fields, ", ", &expr(&1, sources, query))]
     end
 
     defp window_expr({:order_by, fields}, sources, query) do
       ["ORDER BY " | intersperse_map(fields, ", ", &order_by_expr(&1, sources, query))]
     end
 
     defp window_expr({:frame, {:fragment, _, _} = fragment}, sources, query) do
       expr(fragment, sources, query)
     end
 
     defp order_by(%{order_bys: []}, _distinct, _sources), do: []
     defp order_by(%{order_bys: order_bys} = query, distinct, sources) do
       order_bys = Enum.flat_map(order_bys, & &1.expr)
       order_bys = order_by_concat(distinct, order_bys)
       [" ORDER BY " | intersperse_map(order_bys, ", ", &order_by_expr(&1, sources, query))]
     end
 
     defp order_by_concat([head | left], [head | right]), do: [head | order_by_concat(left, right)]
     defp order_by_concat(left, right), do: left ++ right
 
     defp order_by_expr({dir, expr}, sources, query) do
       str = expr(expr, sources, query)
 
       case dir do
         :asc  -> str
         :asc_nulls_last -> [str | " ASC NULLS LAST"]
         :asc_nulls_first -> [str | " ASC NULLS FIRST"]
         :desc -> [str | " DESC"]
         :desc_nulls_last -> [str | " DESC NULLS LAST"]
         :desc_nulls_first -> [str | " DESC NULLS FIRST"]
       end
     end
 
     defp limit(%{limit: nil}, _sources), do: []
     defp limit(%{limit: %QueryExpr{expr: expr}} = query, sources) do
       [" LIMIT " | expr(expr, sources, query)]
     end
 
     defp offset(%{offset: nil}, _sources), do: []
     defp offset(%{offset: %QueryExpr{expr: expr}} = query, sources) do
       [" OFFSET " | expr(expr, sources, query)]
     end
 
     defp combinations(%{combinations: combinations}) do
       Enum.map(combinations, fn
         {:union, query} -> [" UNION (", all(query), ")"]
         {:union_all, query} -> [" UNION ALL (", all(query), ")"]
         {:except, query} -> [" EXCEPT (", all(query), ")"]
         {:except_all, query} -> [" EXCEPT ALL (", all(query), ")"]
         {:intersect, query} -> [" INTERSECT (", all(query), ")"]
         {:intersect_all, query} -> [" INTERSECT ALL (", all(query), ")"]
       end)
     end
 
     defp lock(%{lock: nil}, _sources), do: []
     defp lock(%{lock: binary}, _sources) when is_binary(binary), do: [?\s | binary]
     defp lock(%{lock: expr} = query, sources), do: [?\s | expr(expr, sources, query)]
 
     defp boolean(_name, [], _sources, _query), do: []
     defp boolean(name, [%{expr: expr, op: op} | query_exprs], sources, query) do
       [name |
        Enum.reduce(query_exprs, {op, paren_expr(expr, sources, query)}, fn
          %BooleanExpr{expr: expr, op: op}, {op, acc} ->
            {op, [acc, operator_to_boolean(op), paren_expr(expr, sources, query)]}
          %BooleanExpr{expr: expr, op: op}, {_, acc} ->
            {op, [?(, acc, ?), operator_to_boolean(op), paren_expr(expr, sources, query)]}
        end) |> elem(1)]
     end
 
     defp operator_to_boolean(:and), do: " AND "
     defp operator_to_boolean(:or), do: " OR "
 
     defp parens_for_select([first_expr | _] = expr) do
       if is_binary(first_expr) and String.match?(first_expr, ~r/^\s*select/i) do
         [?(, expr, ?)]
       else
         expr
       end
     end
 
     defp paren_expr(expr, sources, query) do
       [?(, expr(expr, sources, query), ?)]
     end
 
     defp expr({:^, [], [ix]}, _sources, _query) do
       [?$ | Integer.to_string(ix + 1)]
     end
 
     defp expr({{:., _, [{:parent_as, _, [as]}, field]}, _, []}, _sources, query)
          when is_atom(field) do
       {ix, sources} = get_parent_sources_ix(query, as)
       quote_qualified_name(field, sources, ix)
     end
 
     defp expr({{:., _, [{:&, _, [idx]}, field]}, _, []}, sources, _query) when is_atom(field) do
       quote_qualified_name(field, sources, idx)
     end
 
     defp expr({:&, _, [idx]}, sources, _query) do
       {_, source, _} = elem(sources, idx)
       source
     end
 
     defp expr({:in, _, [_left, []]}, _sources, _query) do
       "false"
     end
 
     defp expr({:in, _, [left, right]}, sources, query) when is_list(right) do
       args = intersperse_map(right, ?,, &expr(&1, sources, query))
       [expr(left, sources, query), " IN (", args, ?)]
     end
 
     defp expr({:in, _, [left, {:^, _, [ix, _]}]}, sources, query) do
       [expr(left, sources, query), " = ANY($", Integer.to_string(ix + 1), ?)]
     end
 
     defp expr({:in, _, [left, %Ecto.SubQuery{} = subquery]}, sources, query) do
       [expr(left, sources, query), " IN ", expr(subquery, sources, query)]
     end
 
     defp expr({:in, _, [left, right]}, sources, query) do
       [expr(left, sources, query), " = ANY(", expr(right, sources, query), ?)]
     end
 
     defp expr({:is_nil, _, [arg]}, sources, query) do
       [expr(arg, sources, query) | " IS NULL"]
     end
 
     defp expr({:not, _, [expr]}, sources, query) do
       ["NOT (", expr(expr, sources, query), ?)]
     end
 
     defp expr(%Ecto.SubQuery{query: query}, sources, parent_query) do
       query = put_in(query.aliases[@parent_as], {parent_query, sources})
       [?(, all(query, subquery_as_prefix(sources)), ?)]
     end
 
     defp expr({:fragment, _, [kw]}, _sources, query) when is_list(kw) or tuple_size(kw) == 3 do
       error!(query, "PostgreSQL adapter does not support keyword or interpolated fragments")
     end
 
     defp expr({:fragment, _, parts}, sources, query) do
       Enum.map(parts, fn
         {:raw, part}  -> part
         {:expr, expr} -> expr(expr, sources, query)
       end)
       |> parens_for_select
     end
 
     defp expr({:literal, _, [literal]}, _sources, _query) do
       quote_name(literal)
     end
 
     defp expr({:selected_as, _, [name]}, _sources, _query) do
       [quote_name(name)]
     end
 
     defp expr({:datetime_add, _, [datetime, count, interval]}, sources, query) do
       [expr(datetime, sources, query), type_unless_typed(datetime, "timestamp"), " + ",
        interval(count, interval, sources, query)]
     end
 
     defp expr({:date_add, _, [date, count, interval]}, sources, query) do
       [?(, expr(date, sources, query), type_unless_typed(date, "date"), " + ",
        interval(count, interval, sources, query) | ")::date"]
     end
 
     defp expr({:json_extract_path, _, [expr, path]}, sources, query) do
       json_extract_path(expr, path, sources, query)
     end
 
     defp expr({:filter, _, [agg, filter]}, sources, query) do
       aggregate = expr(agg, sources, query)
       [aggregate, " FILTER (WHERE ", expr(filter, sources, query), ?)]
     end
 
     defp expr({:over, _, [agg, name]}, sources, query) when is_atom(name) do
       aggregate = expr(agg, sources, query)
       [aggregate, " OVER " | quote_name(name)]
     end
 
     defp expr({:over, _, [agg, kw]}, sources, query) do
       aggregate = expr(agg, sources, query)
       [aggregate, " OVER ", window_exprs(kw, sources, query)]
     end
 
     defp expr({:{}, _, elems}, sources, query) do
       [?(, intersperse_map(elems, ?,, &expr(&1, sources, query)), ?)]
     end
 
     defp expr({:count, _, []}, _sources, _query), do: "count(*)"
 
     defp expr({:==, _, [{:json_extract_path, _, [expr, path]} = left, right]}, sources, query)
          when is_binary(right) or is_integer(right) or is_boolean(right) do
       case Enum.split(path, -1) do
         {path, [last]} when is_binary(last) ->
           extracted = json_extract_path(expr, path, sources, query)
           [?(, extracted, "@>'{", escape_json(last), ": ", escape_json(right) | "}')"]
 
         _ ->
           [maybe_paren(left, sources, query), " = " | maybe_paren(right, sources, query)]
       end
     end
 
     defp expr({fun, _, args}, sources, query) when is_atom(fun) and is_list(args) do
       {modifier, args} =
         case args do
           [rest, :distinct] -> {"DISTINCT ", [rest]}
           _ -> {[], args}
         end
 
       case handle_call(fun, length(args)) do
         {:binary_op, op} ->
           [left, right] = args
           [maybe_paren(left, sources, query), op | maybe_paren(right, sources, query)]
         {:fun, fun} ->
           [fun, ?(, modifier, intersperse_map(args, ", ", &expr(&1, sources, query)), ?)]
       end
     end
 
     defp expr(list, sources, query) when is_list(list) do
       ["ARRAY[", intersperse_map(list, ?,, &expr(&1, sources, query)), ?]]
     end
 
     defp expr(%Decimal{} = decimal, _sources, _query) do
       Decimal.to_string(decimal, :normal)
     end
 
     defp expr(%Ecto.Query.Tagged{value: binary, type: :binary}, _sources, _query)
         when is_binary(binary) do
       ["'\\x", Base.encode16(binary, case: :lower) | "'::bytea"]
     end
 
     defp expr(%Ecto.Query.Tagged{value: other, type: type}, sources, query) do
       [maybe_paren(other, sources, query), ?:, ?: | tagged_to_db(type)]
     end
 
     defp expr(nil, _sources, _query),   do: "NULL"
     defp expr(true, _sources, _query),  do: "TRUE"
     defp expr(false, _sources, _query), do: "FALSE"
 
     defp expr(literal, _sources, _query) when is_binary(literal) do
       [?\', escape_string(literal), ?\']
     end
 
     defp expr(literal, _sources, _query) when is_integer(literal) do
       Integer.to_string(literal)
     end
 
     defp expr(literal, _sources, _query) when is_float(literal) do
       [Float.to_string(literal) | "::float"]
     end
 
     defp expr(expr, _sources, query) do
       error!(query, "unsupported expression: #{inspect(expr)}")
     end
 
     defp json_extract_path(expr, [], sources, query) do
       expr(expr, sources, query)
     end
 
     defp json_extract_path(expr, path, sources, query) do
       path = intersperse_map(path, ?,, &escape_json/1)
       [?(, expr(expr, sources, query), "#>'{", path, "}')"]
     end
 
     defp type_unless_typed(%Ecto.Query.Tagged{}, _type), do: []
     defp type_unless_typed(_, type), do: [?:, ?: | type]
 
     # Always use the largest possible type for integers
     defp tagged_to_db(:id), do: "bigint"
     defp tagged_to_db(:integer), do: "bigint"
     defp tagged_to_db({:array, type}), do: [tagged_to_db(type), ?[, ?]]
     defp tagged_to_db(type), do: ecto_to_db(type)
 
     defp interval(count, interval, _sources, _query) when is_integer(count) do
       ["interval '", String.Chars.Integer.to_string(count), ?\s, interval, ?\']
     end
 
     defp interval(count, interval, _sources, _query) when is_float(count) do
       count = :erlang.float_to_binary(count, [:compact, decimals: 16])
       ["interval '", count, ?\s, interval, ?\']
     end
 
     defp interval(count, interval, sources, query) do
       [?(, expr(count, sources, query), "::numeric * ",
        interval(1, interval, sources, query), ?)]
     end
 
     defp maybe_paren({op, _, [_, _]} = expr, sources, query) when op in @binary_ops,
       do: paren_expr(expr, sources, query)
 
     defp maybe_paren({:is_nil, _, [_]} = expr, sources, query),
       do: paren_expr(expr, sources, query)
 
     defp maybe_paren(expr, sources, query),
       do: expr(expr, sources, query)
 
     defp returning(%{select: nil}, _sources),
       do: []
     defp returning(%{select: %{fields: fields}} = query, sources),
       do: [" RETURNING " | select_fields(fields, sources, query)]
 
     defp returning([]),
       do: []
     defp returning(returning),
       do: [" RETURNING " | quote_names(returning)]
 
     defp create_names(%{sources: sources}, as_prefix) do
       create_names(sources, 0, tuple_size(sources), as_prefix) |> List.to_tuple()
     end
 
     defp create_names(sources, pos, limit, as_prefix) when pos < limit do
       [create_name(sources, pos, as_prefix) | create_names(sources, pos + 1, limit, as_prefix)]
     end
 
     defp create_names(_sources, pos, pos, as_prefix) do
       [as_prefix]
     end
 
     defp subquery_as_prefix(sources) do
       [?s | :erlang.element(tuple_size(sources), sources)]
     end
 
     defp create_name(sources, pos, as_prefix) do
       case elem(sources, pos) do
         {:fragment, _, _} ->
           {nil, as_prefix ++ [?f | Integer.to_string(pos)], nil}
 
         {table, schema, prefix} ->
           name = as_prefix ++ [create_alias(table) | Integer.to_string(pos)]
           {quote_table(prefix, table), name, schema}
 
         %Ecto.SubQuery{} ->
           {nil, as_prefix ++ [?s | Integer.to_string(pos)], nil}
       end
     end
 
     defp create_alias(<<first, _rest::binary>>) when first in ?a..?z when first in ?A..?Z do
       first
     end
     defp create_alias(_) do
       ?t
     end
 
     # DDL
 
     alias Ecto.Migration.{Table, Index, Reference, Constraint}
 
     @creates [:create, :create_if_not_exists]
     @drops [:drop, :drop_if_exists]
 
     @impl true
     def execute_ddl({command, %Table{} = table, columns}) when command in @creates do
       table_name = quote_table(table.prefix, table.name)
       query = ["CREATE TABLE ",
                if_do(command == :create_if_not_exists, "IF NOT EXISTS "),
                table_name, ?\s, ?(,
                column_definitions(table, columns), pk_definition(columns, ", "), ?),
                options_expr(table.options)]
 
       [query] ++
         comments_on("TABLE", table_name, table.comment) ++
         comments_for_columns(table_name, columns)
     end
 
     def execute_ddl({command, %Table{} = table, mode}) when command in @drops do
       [["DROP TABLE ", if_do(command == :drop_if_exists, "IF EXISTS "),
         quote_table(table.prefix, table.name), drop_mode(mode)]]
     end
 
     def execute_ddl({:alter, %Table{} = table, changes}) do
       table_name = quote_table(table.prefix, table.name)
       query = ["ALTER TABLE ", table_name, ?\s,
                column_changes(table, changes), pk_definition(changes, ", ADD ")]
 
       [query] ++
         comments_on("TABLE", table_name, table.comment) ++
         comments_for_columns(table_name, changes)
     end
 
     def execute_ddl({command, %Index{} = index}) when command in @creates do
       fields = intersperse_map(index.columns, ", ", &index_expr/1)
       include_fields = intersperse_map(index.include, ", ", &index_expr/1)
 
       maybe_nulls_distinct =
         case index.nulls_distinct do
           nil -> []
           true -> " NULLS DISTINCT"
           false -> " NULLS NOT DISTINCT"
         end
 
       queries = [["CREATE ",
                   if_do(index.unique, "UNIQUE "),
                   "INDEX ",
                   if_do(index.concurrently, "CONCURRENTLY "),
                   if_do(command == :create_if_not_exists, "IF NOT EXISTS "),
                   quote_name(index.name),
                   " ON ",
                   quote_table(index.prefix, index.table),
                   if_do(index.using, [" USING " , to_string(index.using)]),
                   ?\s, ?(, fields, ?),
                   if_do(include_fields != [], [" INCLUDE ", ?(, include_fields, ?)]),
                   maybe_nulls_distinct,
                   if_do(index.where, [" WHERE ", to_string(index.where)])]]
 
       queries ++ comments_on("INDEX", quote_table(index.prefix, index.name), index.comment)
     end
 
     def execute_ddl({command, %Index{} = index, mode}) when command in @drops do
       [["DROP INDEX ",
         if_do(index.concurrently, "CONCURRENTLY "),
         if_do(command == :drop_if_exists, "IF EXISTS "),
         quote_table(index.prefix, index.name),
         drop_mode(mode)]]
     end
 
     def execute_ddl({:rename, %Table{} = current_table, %Table{} = new_table}) do
       [["ALTER TABLE ", quote_table(current_table.prefix, current_table.name),
         " RENAME TO ", quote_table(nil, new_table.name)]]
     end
 
     def execute_ddl({:rename, %Table{} = table, current_column, new_column}) do
       [["ALTER TABLE ", quote_table(table.prefix, table.name), " RENAME ",
         quote_name(current_column), " TO ", quote_name(new_column)]]
     end
 
     def execute_ddl({:create, %Constraint{} = constraint}) do
       table_name = quote_table(constraint.prefix, constraint.table)
       queries = [["ALTER TABLE ", table_name,
                   " ADD ", new_constraint_expr(constraint)]]
 
       queries ++ comments_on("CONSTRAINT", constraint.name, constraint.comment, table_name)
     end
 
     def execute_ddl({command, %Constraint{}, :cascade}) when command in @drops,
       do: error!(nil, "PostgreSQL does not support `CASCADE` in DROP CONSTRAINT commands")
 
     def execute_ddl({command, %Constraint{} = constraint, :restrict}) when command in @drops do
       [["ALTER TABLE ", quote_table(constraint.prefix, constraint.table),
         " DROP CONSTRAINT ", if_do(command == :drop_if_exists, "IF EXISTS "), quote_name(constraint.name)]]
     end
 
     def execute_ddl(string) when is_binary(string), do: [string]
 
     def execute_ddl(keyword) when is_list(keyword),
       do: error!(nil, "PostgreSQL adapter does not support keyword lists in execute")
 
     @impl true
     def ddl_logs(%Postgrex.Result{} = result) do
       %{messages: messages} = result
 
       for message <- messages do
         %{message: message, severity: severity} = message
 
         {ddl_log_level(severity), message, []}
       end
     end
 
     @impl true
     def table_exists_query(table) do
       {"SELECT true FROM information_schema.tables WHERE table_name = $1 AND table_schema = current_schema() LIMIT 1", [table]}
     end
 
     defp drop_mode(:cascade), do: " CASCADE"
     defp drop_mode(:restrict), do: []
 
     # From https://www.postgresql.org/docs/current/protocol-error-fields.html.
     defp ddl_log_level("DEBUG"), do: :debug
     defp ddl_log_level("LOG"), do: :info
     defp ddl_log_level("INFO"), do: :info
     defp ddl_log_level("NOTICE"), do: :info
     defp ddl_log_level("WARNING"), do: :warn
     defp ddl_log_level("ERROR"), do: :error
     defp ddl_log_level("FATAL"), do: :error
     defp ddl_log_level("PANIC"), do: :error
     defp ddl_log_level(_severity), do: :info
 
     defp pk_definition(columns, prefix) do
       pks =
         for {_, name, _, opts} <- columns,
             opts[:primary_key],
             do: name
 
       case pks do
         [] -> []
         _  -> [prefix, "PRIMARY KEY (", quote_names(pks), ")"]
       end
     end
 
     defp comments_on(_object, _name, nil), do: []
     defp comments_on(object, name, comment) do
       [["COMMENT ON ", object, ?\s, name, " IS ", single_quote(comment)]]
     end
 
     defp comments_on(_object, _name, nil, _table_name), do:  []
     defp comments_on(object, name, comment, table_name) do
       [["COMMENT ON ", object, ?\s, quote_name(name), " ON ", table_name,
         " IS ", single_quote(comment)]]
     end
 
     defp comments_for_columns(table_name, columns) do
       Enum.flat_map(columns, fn
         {_operation, column_name, _column_type, opts} ->
           column_name = [table_name, ?. | quote_name(column_name)]
           comments_on("COLUMN", column_name, opts[:comment])
         _ -> []
       end)
     end
 
     defp column_definitions(table, columns) do
       intersperse_map(columns, ", ", &column_definition(table, &1))
     end
 
     defp column_definition(table, {:add, name, %Reference{} = ref, opts}) do
       [quote_name(name), ?\s, reference_column_type(ref.type, opts),
        column_options(ref.type, opts), ", ", reference_expr(ref, table, name)]
     end
 
     defp column_definition(_table, {:add, name, type, opts}) do
       [quote_name(name), ?\s, column_type(type, opts), column_options(type, opts)]
     end
 
     defp column_changes(table, columns) do
       intersperse_map(columns, ", ", &column_change(table, &1))
     end
 
     defp column_change(table, {:add, name, %Reference{} = ref, opts}) do
       ["ADD COLUMN ", quote_name(name), ?\s, reference_column_type(ref.type, opts),
        column_options(ref.type, opts), ", ADD ", reference_expr(ref, table, name)]
     end
 
     defp column_change(_table, {:add, name, type, opts}) do
       ["ADD COLUMN ", quote_name(name), ?\s, column_type(type, opts),
        column_options(type, opts)]
     end
 
     defp column_change(table, {:add_if_not_exists, name, %Reference{} = ref, opts}) do
       ["ADD COLUMN IF NOT EXISTS ", quote_name(name), ?\s, reference_column_type(ref.type, opts),
        column_options(ref.type, opts), ", ADD ", reference_expr(ref, table, name)]
     end
 
     defp column_change(_table, {:add_if_not_exists, name, type, opts}) do
       ["ADD COLUMN IF NOT EXISTS ", quote_name(name), ?\s, column_type(type, opts),
        column_options(type, opts)]
     end
 
     defp column_change(table, {:modify, name, %Reference{} = ref, opts}) do
       [drop_reference_expr(opts[:from], table, name), "ALTER COLUMN ", quote_name(name),
       " TYPE ", reference_column_type(ref.type, opts),
        ", ADD ", reference_expr(ref, table, name),
        modify_null(name, opts), modify_default(name, ref.type, opts)]
     end
 
     defp column_change(table, {:modify, name, type, opts}) do
       [drop_reference_expr(opts[:from], table, name), "ALTER COLUMN ", quote_name(name), " TYPE ",
        column_type(type, opts), modify_null(name, opts), modify_default(name, type, opts)]
     end
 
     defp column_change(_table, {:remove, name}), do: ["DROP COLUMN ", quote_name(name)]
     defp column_change(table, {:remove, name, %Reference{} = ref, _opts}) do
       [drop_reference_expr(ref, table, name), "DROP COLUMN ", quote_name(name)]
     end
     defp column_change(_table, {:remove, name, _type, _opts}), do: ["DROP COLUMN ", quote_name(name)]
 
     defp column_change(table, {:remove_if_exists, name, %Reference{} = ref}) do
       [drop_reference_if_exists_expr(ref, table, name), "DROP COLUMN IF EXISTS ", quote_name(name)]
     end
     defp column_change(_table, {:remove_if_exists, name, _type}), do: ["DROP COLUMN IF EXISTS ", quote_name(name)]
 
     defp modify_null(name, opts) do
       case Keyword.get(opts, :null) do
         true  -> [", ALTER COLUMN ", quote_name(name), " DROP NOT NULL"]
         false -> [", ALTER COLUMN ", quote_name(name), " SET NOT NULL"]
         nil   -> []
       end
     end
 
     defp modify_default(name, type, opts) do
       case Keyword.fetch(opts, :default) do
         {:ok, val} -> [", ALTER COLUMN ", quote_name(name), " SET", default_expr({:ok, val}, type)]
         :error -> []
       end
     end
 
     defp column_options(type, opts) do
       default = Keyword.fetch(opts, :default)
       null    = Keyword.get(opts, :null)
 
       [default_expr(default, type), null_expr(null)]
     end
 
     defp null_expr(false), do: " NOT NULL"
     defp null_expr(true), do: " NULL"
     defp null_expr(_), do: []
 
     defp new_constraint_expr(%Constraint{check: check} = constraint) when is_binary(check) do
       ["CONSTRAINT ", quote_name(constraint.name), " CHECK (", check, ")", validate(constraint.validate)]
     end
     defp new_constraint_expr(%Constraint{exclude: exclude} = constraint) when is_binary(exclude) do
       ["CONSTRAINT ", quote_name(constraint.name), " EXCLUDE USING ", exclude, validate(constraint.validate)]
     end
 
     defp default_expr({:ok, nil}, _type),    do: " DEFAULT NULL"
     defp default_expr({:ok, literal}, type), do: [" DEFAULT ", default_type(literal, type)]
     defp default_expr(:error, _),            do: []
 
     defp default_type(list, {:array, inner} = type) when is_list(list) do
       ["ARRAY[",  Enum.map(list, &default_type(&1, inner)) |> Enum.intersperse(?,), "]::", ecto_to_db(type)]
     end
     defp default_type(literal, _type) when is_binary(literal) do
       if :binary.match(literal, <<0>>) == :nomatch and String.valid?(literal) do
         single_quote(literal)
       else
         encoded = "\\x" <> Base.encode16(literal, case: :lower)
         raise ArgumentError, "default values are interpolated as UTF-8 strings and cannot contain null bytes. " <>
                              "`#{inspect literal}` is invalid. If you want to write it as a binary, use \"#{encoded}\", " <>
                              "otherwise refer to PostgreSQL documentation for instructions on how to escape this SQL type"
       end
     end
     defp default_type(literal, _type) when is_number(literal),  do: to_string(literal)
     defp default_type(literal, _type) when is_boolean(literal), do: to_string(literal)
     defp default_type(%{} = map, :map) do
       library = Application.get_env(:postgrex, :json_library, Jason)
       default = IO.iodata_to_binary(library.encode_to_iodata!(map))
       [single_quote(default)]
     end
     defp default_type({:fragment, expr}, _type),
       do: [expr]
     defp default_type(expr, type),
       do: raise(ArgumentError, "unknown default `#{inspect expr}` for type `#{inspect type}`. " <>
                                ":default may be a string, number, boolean, list of strings, list of integers, map (when type is Map), or a fragment(...)")
 
     defp index_expr(literal) when is_binary(literal),
       do: literal
     defp index_expr(literal),
       do: quote_name(literal)
 
     defp options_expr(nil),
       do: []
     defp options_expr(keyword) when is_list(keyword),
       do: error!(nil, "PostgreSQL adapter does not support keyword lists in :options")
     defp options_expr(options),
       do: [?\s, options]
 
     defp column_type({:array, type}, opts),
       do: [column_type(type, opts), "[]"]
 
     defp column_type(type, _opts) when type in ~w(time utc_datetime naive_datetime)a,
       do: [ecto_to_db(type), "(0)"]
 
     defp column_type(type, opts) when type in ~w(time_usec utc_datetime_usec naive_datetime_usec)a do
       precision = Keyword.get(opts, :precision)
       type_name = ecto_to_db(type)
 
       if precision do
         [type_name, ?(, to_string(precision), ?)]
       else
         type_name
       end
     end
 
     defp column_type(:identity, opts) do
       start_value = [Keyword.get(opts, :start_value)]
       increment   = [Keyword.get(opts, :increment)]
       type_name   = ecto_to_db(:identity)
 
       cleanup = fn v -> is_integer(v) and v > 0 end
 
       sequence =
         start_value
         |> Enum.filter(cleanup)
         |> Enum.map(&"START WITH #{&1}")
         |> Kernel.++(
           increment
           |> Enum.filter(cleanup)
           |> Enum.map(&"INCREMENT BY #{&1}")
         )
 
       case sequence do
         [] -> [type_name, " GENERATED BY DEFAULT AS IDENTITY"]
         _ ->  [type_name, " GENERATED BY DEFAULT AS IDENTITY(", Enum.join(sequence, " "), ") "]
       end
     end
 
     defp column_type(type, opts) do
       size      = Keyword.get(opts, :size)
       precision = Keyword.get(opts, :precision)
       scale     = Keyword.get(opts, :scale)
       type_name = ecto_to_db(type)
 
       cond do
         size            -> [type_name, ?(, to_string(size), ?)]
         precision       -> [type_name, ?(, to_string(precision), ?,, to_string(scale || 0), ?)]
         type == :string -> [type_name, "(255)"]
         true            -> type_name
       end
     end
 
     defp reference_expr(%Reference{} = ref, table, name) do
       {current_columns, reference_columns} = Enum.unzip([{name, ref.column} | ref.with])
 
       ["CONSTRAINT ", reference_name(ref, table, name), ?\s,
        "FOREIGN KEY (", quote_names(current_columns), ") REFERENCES ",
        quote_table(ref.prefix || table.prefix, ref.table), ?(, quote_names(reference_columns), ?),
        reference_match(ref.match), reference_on_delete(ref.on_delete),
        reference_on_update(ref.on_update), validate(ref.validate)]
     end
 
     defp drop_reference_expr(%Reference{} = ref, table, name),
       do: ["DROP CONSTRAINT ", reference_name(ref, table, name), ", "]
     defp drop_reference_expr(_, _, _),
       do: []
 
     defp drop_reference_if_exists_expr(%Reference{} = ref, table, name),
       do: ["DROP CONSTRAINT IF EXISTS ", reference_name(ref, table, name), ", "]
     defp drop_reference_if_exists_expr(_, _, _),
       do: []
 
     defp reference_name(%Reference{name: nil}, table, column),
       do: quote_name("#{table.name}_#{column}_fkey")
     defp reference_name(%Reference{name: name}, _table, _column),
       do: quote_name(name)
 
     defp reference_column_type(:serial, _opts), do: "integer"
     defp reference_column_type(:bigserial, _opts), do: "bigint"
     defp reference_column_type(:identity, _opts), do: "bigint"
     defp reference_column_type(type, opts), do: column_type(type, opts)
 
     defp reference_on_delete(:nilify_all), do: " ON DELETE SET NULL"
     defp reference_on_delete(:delete_all), do: " ON DELETE CASCADE"
     defp reference_on_delete(:restrict), do: " ON DELETE RESTRICT"
     defp reference_on_delete(_), do: []
 
     defp reference_on_update(:nilify_all), do: " ON UPDATE SET NULL"
     defp reference_on_update(:update_all), do: " ON UPDATE CASCADE"
     defp reference_on_update(:restrict), do: " ON UPDATE RESTRICT"
     defp reference_on_update(_), do: []
 
     defp reference_match(nil), do: []
     defp reference_match(:full), do: " MATCH FULL"
     defp reference_match(:simple), do: " MATCH SIMPLE"
     defp reference_match(:partial), do: " MATCH PARTIAL"
 
     defp validate(false), do: " NOT VALID"
     defp validate(_), do: []
 
     ## Helpers
 
     defp get_source(query, sources, ix, source) do
       {expr, name, _schema} = elem(sources, ix)
       {expr || expr(source, sources, query), name}
     end
 
     defp get_parent_sources_ix(query, as) do
       case query.aliases[@parent_as] do
         {%{aliases: %{^as => ix}}, sources} -> {ix, sources}
         {%{} = parent, _sources} -> get_parent_sources_ix(parent, as)
       end
     end
 
     defp quote_qualified_name(name, sources, ix) do
       {_, source, _} = elem(sources, ix)
       [source, ?. | quote_name(name)]
     end
 
     defp quote_names(names) do
       intersperse_map(names, ?,, &quote_name/1)
     end
 
     defp quote_name(name) when is_atom(name) do
       quote_name(Atom.to_string(name))
     end
 
     defp quote_name(name) when is_binary(name) do
       if String.contains?(name, "\"") do
         error!(nil, "bad literal/field/table name #{inspect name} (\" is not permitted)")
       end
 
       [?", name, ?"]
     end
 
     defp quote_table(nil, name),    do: quote_table(name)
     defp quote_table(prefix, name), do: [quote_table(prefix), ?., quote_table(name)]
 
     defp quote_table(name) when is_atom(name),
       do: quote_table(Atom.to_string(name))
     defp quote_table(name) do
       if String.contains?(name, "\"") do
         error!(nil, "bad table name #{inspect name}")
       end
       [?", name, ?"]
     end
 
     # TRUE, ON, or 1 to enable the option, and FALSE, OFF, or 0 to disable it
     defp quote_boolean(nil), do: nil
     defp quote_boolean(true), do: "TRUE"
     defp quote_boolean(false), do: "FALSE"
     defp quote_boolean(value), do: error!(nil, "bad boolean value #{value}")
 
     defp format_to_sql(:text), do: "FORMAT TEXT"
     defp format_to_sql(:map), do: "FORMAT JSON"
     defp format_to_sql(:yaml), do: "FORMAT YAML"
 
     defp single_quote(value), do: [?', escape_string(value), ?']
 
     defp intersperse_map(list, separator, mapper, acc \\ [])
     defp intersperse_map([], _separator, _mapper, acc),
       do: acc
     defp intersperse_map([elem], _separator, mapper, acc),
       do: [acc | mapper.(elem)]
     defp intersperse_map([elem | rest], separator, mapper, acc),
       do: intersperse_map(rest, separator, mapper, [acc, mapper.(elem), separator])
 
     defp intersperse_reduce(list, separator, user_acc, reducer, acc \\ [])
     defp intersperse_reduce([], _separator, user_acc, _reducer, acc),
       do: {acc, user_acc}
     defp intersperse_reduce([elem], _separator, user_acc, reducer, acc) do
       {elem, user_acc} = reducer.(elem, user_acc)
       {[acc | elem], user_acc}
     end
     defp intersperse_reduce([elem | rest], separator, user_acc, reducer, acc) do
       {elem, user_acc} = reducer.(elem, user_acc)
       intersperse_reduce(rest, separator, user_acc, reducer, [acc, elem, separator])
     end
 
     defp if_do(condition, value) do
       if condition, do: value, else: []
     end
 
     defp escape_string(value) when is_binary(value) do
       :binary.replace(value, "'", "''", [:global])
     end
 
     defp escape_json(value) when is_binary(value) do
       escaped =
         value
         |> escape_string()
         |> :binary.replace("\"", "\\\"", [:global])
 
       [?", escaped, ?"]
     end
 
     defp escape_json(value) when is_integer(value) do
       Integer.to_string(value)
     end
 
     defp escape_json(true), do: ["true"]
     defp escape_json(false), do: ["false"]
 
     defp ecto_to_db({:array, t}),          do: [ecto_to_db(t), ?[, ?]]
     defp ecto_to_db(:id),                  do: "integer"
     defp ecto_to_db(:identity),            do: "bigint"
     defp ecto_to_db(:serial),              do: "serial"
     defp ecto_to_db(:bigserial),           do: "bigserial"
     defp ecto_to_db(:binary_id),           do: "uuid"
     defp ecto_to_db(:string),              do: "varchar"
     defp ecto_to_db(:binary),              do: "bytea"
     defp ecto_to_db(:map),                 do: Application.fetch_env!(:ecto_sql, :postgres_map_type)
     defp ecto_to_db({:map, _}),            do: Application.fetch_env!(:ecto_sql, :postgres_map_type)
     defp ecto_to_db(:time_usec),           do: "time"
     defp ecto_to_db(:utc_datetime),        do: "timestamp"
     defp ecto_to_db(:utc_datetime_usec),   do: "timestamp"
     defp ecto_to_db(:naive_datetime),      do: "timestamp"
     defp ecto_to_db(:naive_datetime_usec), do: "timestamp"
     defp ecto_to_db(atom) when is_atom(atom),  do: Atom.to_string(atom)
     defp ecto_to_db(type) do
       raise ArgumentError,
             "unsupported type `#{inspect(type)}`. The type can either be an atom, a string " <>
               "or a tuple of the form `{:map, t}` or `{:array, t}` where `t` itself follows the same conditions."
     end
 
     defp error!(nil, message) do
       raise ArgumentError, message
     end
     defp error!(query, message) do
       raise Ecto.QueryError, query: query, message: message
     end
   end
 end