以下SQL脚本，以下哪些查询会从表myTable中返回column1字段为NULL记录？( )
SELECT * FROM myTable WHERE column1 IS NOT NULL:
SELECT * FROM myTable WHERE column1
SELECT * FROM myTable WHERE column1 IS NULL:
都不是
青云测评
青云测评
以下SQL脚本，以下哪些查询会从表myTable中返回column1字段为NULL记录？( )
SELECT * FROM myTable WHERE column1 IS NOT NULL:
SELECT * FROM myTable WHERE column1
SELECT * FROM myTable WHERE column1 IS NULL:
都不是
