SAP HANA SQLScript 的 SQL“IS NOT NULL”补偿

Question

Actually I tried to run a is null SQL Statement on a SAP HANA Database using the SAP HANA Studio. This does not work because SQLScript has no is not null or is null function. My statement looks like:

Select *
From MSEG
Where KDAUF is null

Unfortunately it does not work. Does anybody know an alternative approach which is practicable using SAP HANA SQLScript? On the internet I found a hint to either use NULLIF or COALESCE . But I neither know how to use this function nor to adapt it to a working WHERE condition.

Answer 1

NULLIF ( expression , expression ) Returns the same type as the first expression.

NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression WHERE IFNULL(KDAUF , comparison value) I never use this one

The other is coalesce where if the first vaLue is null, the second VALUE is returned:

WHERE VALUEa = COALESCE(KDAUF,valuea)

here, if kdaUf Is null, coalesce will will return valuea, the default if the first value is null. Since valuea = valuea, the where clause will be true, which is just another way of validating that KDAUF IS NULL

Answer 2

尝试以这种方式使用它

Select * from MSEG Where KDAUF **NE** ''