Interface AggCall

core/src/main/java/org/apache/calcite/tools/RelBuilder.java:4333–4397

Information necessary to create a call to an aggregate function. @see RelBuilder#aggregateCall

   *
   * @see RelBuilder#aggregateCall */
  public interface AggCall {
    SqlParserPos getPosition();

    /** Returns a copy of this AggCall that applies a filter before aggregating
     * values. */
    AggCall filter(@Nullable RexNode condition);

    /** Returns a copy of this AggCall that sorts its input values by
     * {@code orderKeys} before aggregating, as in SQL's {@code WITHIN GROUP}
     * clause. */
    AggCall sort(Iterable<RexNode> orderKeys);

    /** Returns a copy of this AggCall that sorts its input values by
     * {@code orderKeys} before aggregating, as in SQL's {@code WITHIN GROUP}
     * clause. */
    default AggCall sort(RexNode... orderKeys) {
      return sort(ImmutableList.copyOf(orderKeys));
    }

    /** Returns a copy of this AggCall with the given pre-operands.
     *
     * <p>Pre-operands apply at the start of aggregation and are constant for
     * the whole query. They do not reference input columns and are typically
     * {@link RexLiteral}. An example is
     * {@link org.apache.calcite.sql.fun.SqlInternalOperators#LITERAL_AGG};
     * most aggregate functions do not take pre-operands. */
    AggCall preOperands(Iterable<? extends RexNode> preOperands);

    default AggCall preOperands(RexNode... preOperands) {
      return preOperands(ImmutableList.copyOf(preOperands));
    }

    /** Returns a copy of this AggCall that makes its input values unique by
     * {@code distinctKeys} before aggregating, as in SQL's
     * {@code WITHIN DISTINCT} clause. */
    AggCall unique(@Nullable Iterable<RexNode> distinctKeys);

    /** Returns a copy of this AggCall that makes its input values unique by
     * {@code distinctKeys} before aggregating, as in SQL's
     * {@code WITHIN DISTINCT} clause. */
    default AggCall unique(RexNode... distinctKeys) {
      return unique(ImmutableList.copyOf(distinctKeys));
    }

    /** Returns a copy of this AggCall that may return approximate results
     * if {@code approximate} is true. */
    AggCall approximate(boolean approximate);

    /** Returns a copy of this AggCall that ignores nulls. */
    AggCall ignoreNulls(boolean ignoreNulls);

    /** Returns a copy of this AggCall with a given alias. */
    AggCall as(@Nullable String alias);

    /** Returns a copy of this AggCall that is optionally distinct. */
    AggCall distinct(boolean distinct);

    /** Returns a copy of this AggCall that is distinct. */