查询NULL值:
SELECT * FROM `表名` WHERE "字段名" IS NULL
查询非空值:
SELECT * FROM `表名` WHERE "字段名" IS NOT NULL
删除空数据:
DELETE FROM '表名' WHERE '字段名' IS NULL
查询NULL值:
SELECT * FROM `表名` WHERE "字段名" IS NULL
查询非空值:
SELECT * FROM `表名` WHERE "字段名" IS NOT NULL
删除空数据:
DELETE FROM '表名' WHERE '字段名' IS NULL