这篇文章主要介绍了解决mysql使用not in 包含null值的问题，具有很好的参考价值，希望对大家有所帮助。一起跟随小编过来看看吧 注意！！！ select * from user where uid not in (a,b,c,null); 这个sql不回返回任何结果。要避免not in的list中出现null的情况。 另外： –如果null ...

clauses IN and EXISTS are interchangeable. However, they’re quite different in how they handle NULL values and may give different results. The problem comes from the fact that, in an Oracle database, ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...