SQL Server的LEFT JOIN和WHERE子句(SQL Server LEFT JOIN and WHERE clause)

SQL Server的LEFT JOIN和WHERE子句(SQL Server LEFT JOIN and WHERE clause)

这是我的代码

SELECT ID, Name, Phone FROM Table1 LEFT JOIN Table2 ON Table1.ID = Table2.ID WHERE Table1.ID = 12 AND Table2.IsDefault = 1

当Table2为空时，问题发生，因此，查询不会返回任何内容。

如何保留查询的最后部分AND Table2.IsDefault = 1可选？

我试图用OR来短路查询，但我发现它的工作原理与C＃不同，

Here is my code

SELECT ID, Name, Phone FROM Table1 LEFT JOIN Table2 ON Table1.ID = Table2.ID WHERE Table1.ID = 12 AND Table2.IsDefault = 1

The problem happens when Table2 is null, so, the query returns nothing.

How do I leave the last part of the query AND Table2.IsDefault = 1 optional?

I've tried to short circuit the query using OR but I've found out that it works different than C#

最满意答案

SELECT ID, Name, Phone FROM Table1 LEFT JOIN Table2 ON Table1.ID = Table2.ID AND Table2.IsDefault = 1 WHERE Table1.ID = 12 SELECT ID, Name, Phone FROM Table1 LEFT JOIN Table2 ON Table1.ID = Table2.ID AND Table2.IsDefault = 1 WHERE Table1.ID = 12