sql_cond - IS NULL - ABAP Keyword Documentation

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Quick Reference

sql_cond - IS NULL

Syntax

... operand IS [NOT] NULL ...

Effect

This relational expression is true if the value of the operand operand is (is not) the null value. Columns and SQL expressions can be specified for operand. This covers literals, host variables, and host expressions. In a HAVING clause, aggregate expressions can also be used.

Note

The relational expression IS [NOT] NULL is the only expression for which the result is true or false when the operand is given the null value. The result is unknown for all other possible relational expressions in a condition sql_cond when one of the operands in question is given the null value. More specifically, this is relevant for expressions specified as operands when their result is the null value.

Example

Compares the results of an inner and a left outer join. The row with null values produced by the left outer join is removed again by the WHERE condition with IS NOT NULL, so the results are the same.

DELETE FROM demo_join1.
INSERT demo_join1 FROM TABLE @( VALUE #(
  ( a = 'a1' b = 'b1' c = 'c1'  d = 'd1' )
  ( a = 'a2' b = 'b2' c = 'c2'  d = 'd2' ) ) ).

DELETE FROM demo_join2.
INSERT demo_join2 FROM TABLE @( VALUE #(
  ( d = 'd1' e = 'e1' f = 'f1'  g = 'g1'  h = 'h1' ) ) ).

SELECT *
       FROM demo_join1 AS d1
         INNER JOIN demo_join2 AS d2
           ON d1~d = d2~d
       INTO TABLE @DATA(result1).

SELECT *
       FROM demo_join1 AS d1
         LEFT OUTER JOIN demo_join2 AS d2
           ON d1~d = d2~d
       WHERE d2~d IS NOT NULL
       INTO TABLE @DATA(result2).

ASSERT result1 = result2.