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SubExprUtils Utility

SubExprUtils uses PredicateHelper.

SubExprUtils is used to <>.

=== [[hasNullAwarePredicateWithinNot]] Checking If Condition Expression Has Any Null-Aware Predicate Subqueries Inside Not -- hasNullAwarePredicateWithinNot Method

[source, scala]

hasNullAwarePredicateWithinNot(condition: Expression): Boolean

hasNullAwarePredicateWithinNot splits conjunctive predicates (i.e. expressions separated by And expression).

hasNullAwarePredicateWithinNot is positive (i.e. true) and is considered to have a null-aware predicate subquery inside a Not expression when conjuctive predicate expressions include a Not expression with an spark-sql-Expression-In.md[In] predicate expression with a spark-sql-Expression-ListQuery.md[ListQuery] subquery expression.

[source, scala]

import org.apache.spark.sql.catalyst.plans.logical._ import org.apache.spark.sql.catalyst.dsl.plans._ val plan = LocalRelation('key.int, 'value.string).analyze

import org.apache.spark.sql.catalyst.expressions._ val in = In(value = Literal.create(1), Seq(ListQuery(plan))) val condition = Not(child = Or(left = Literal.create(false), right = in))

import org.apache.spark.sql.catalyst.expressions.SubExprUtils val positive = SubExprUtils.hasNullAwarePredicateWithinNot(condition) assert(positive)


hasNullAwarePredicateWithinNot is negative (i.e. false) for all the other expressions and in particular the following expressions:

. spark-sql-Expression-Exists.md[Exists] predicate subquery expressions

. Not expressions with a spark-sql-Expression-Exists.md[Exists] predicate subquery expression as the child expression

. spark-sql-Expression-In.md[In] expressions with a spark-sql-Expression-ListQuery.md[ListQuery] subquery expression as the spark-sql-Expression-In.md#list[list] expression

. Not expressions with a spark-sql-Expression-In.md[In] expression (with a spark-sql-Expression-ListQuery.md[ListQuery] subquery expression as the spark-sql-Expression-In.md#list[list] expression)

[source, scala]

import org.apache.spark.sql.catalyst.plans.logical._ import org.apache.spark.sql.catalyst.dsl.plans._ val plan = LocalRelation('key.int, 'value.string).analyze

import org.apache.spark.sql.catalyst.expressions._ import org.apache.spark.sql.catalyst.expressions.SubExprUtils

// Exists val condition = Exists(plan) val negative = SubExprUtils.hasNullAwarePredicateWithinNot(condition) assert(!negative)

// Not Exists val condition = Not(child = Exists(plan)) val negative = SubExprUtils.hasNullAwarePredicateWithinNot(condition) assert(!negative)

// In with ListQuery val condition = In(value = Literal.create(1), Seq(ListQuery(plan))) val negative = SubExprUtils.hasNullAwarePredicateWithinNot(condition) assert(!negative)

// Not In with ListQuery val in = In(value = Literal.create(1), Seq(ListQuery(plan))) val condition = Not(child = in) val negative = SubExprUtils.hasNullAwarePredicateWithinNot(condition) assert(!negative)


NOTE: hasNullAwarePredicateWithinNot is used exclusively when CheckAnalysis analysis validation is requested to CheckAnalysis.md#checkAnalysis[validate analysis of a logical plan] (with Filter logical operators).

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