SQL MS-Access 中带有 IIF 和 IsNull 的动态 Where 条件

Question

Is it possible to write the WHERE clause with an IIF and an IsNull condition in SQL MS-ACCESS? ie:

SELECT Table1.colx,.... FROM ((Table1 INNER JOIN Table2 ON Table1.col1=Table2.col1) INNER JOIN Table3 ON Table3.col2=Table2.col2) WHERE IIF(IsNull(Table1.colx='someValue1'),Table1.colx='someValue2',Table1.colx='someValue1')

Answer 1

You pretty much never want to use IIF in a WHERE clause. Just use AND , OR , and parentheses.

From your comment, the solution seems simple:

WHERE (TablTe1.colx='someValue1' AND Table1.colx='someValue2' AND TablTe1.colx='someValue1')
OR  ((TablTe1.colx <> 'someValue1' OR Table1.colx <> 'someValue2') AND  Table1.colx='someValue2')