How to use

toExpressionLeafFilter

method

in

org.apache.druid.sql.calcite.expression.Expressions

/**
 * Translates "condition" to a Druid filter, assuming it does not contain any boolean expressions. Returns null
 * if we cannot translate the condition.
 *
 * @param plannerContext planner context
 * @param rowSignature   row signature of the dataSource to be filtered
 * @param rexNode        Calcite row expression
 */
@Nullable
private static DimFilter toLeafFilter(
  final PlannerContext plannerContext,
  final RowSignature rowSignature,
  final RexNode rexNode
)
{
 if (rexNode.isAlwaysTrue()) {
  return Filtration.matchEverything();
 } else if (rexNode.isAlwaysFalse()) {
  return Filtration.matchNothing();
 }
 final DimFilter simpleFilter = toSimpleLeafFilter(plannerContext, rowSignature, rexNode);
 return simpleFilter != null ? simpleFilter : toExpressionLeafFilter(plannerContext, rowSignature, rexNode);
}

/**
 * Translates "condition" to a Druid filter, assuming it does not contain any boolean expressions. Returns null
 * if we cannot translate the condition.
 *
 * @param plannerContext planner context
 * @param rowSignature   row signature of the dataSource to be filtered
 * @param rexNode        Calcite row expression
 */
@Nullable
private static DimFilter toLeafFilter(
  final PlannerContext plannerContext,
  final RowSignature rowSignature,
  final RexNode rexNode
)
{
 if (rexNode.isAlwaysTrue()) {
  return Filtration.matchEverything();
 } else if (rexNode.isAlwaysFalse()) {
  return Filtration.matchNothing();
 }
 final DimFilter simpleFilter = toSimpleLeafFilter(plannerContext, rowSignature, rexNode);
 return simpleFilter != null ? simpleFilter : toExpressionLeafFilter(plannerContext, rowSignature, rexNode);
}