如何写，如果和连接语句在SQL

Question

我如何既如果执行和连接语句在SQL这样的：

if (t1.street != ' ' and t2.street != ' ') 
select * from table1 t1 inner join table2 t2 on t1.street = t2.street. 

sqlfiddle

我想是加入只有两个街道='！ '

谢谢！

Answer 1

http://sqlfiddle.com/#!9/de1be/2/0

select * from table1 t1 
inner join table2 t2 on t1.street = t2.street AND (t1.street != ' ' and t2.street != ' ') 

加入条件的加入

Answer 2

您可以用where条件做到这一点。

SELECT  * 
FROM  table1 t1 
INNER JOIN table2 t2 on t1.street = t2.street 
WHERE  t1.Street != '' 

http://sqlfiddle.com/#!9/6ce8f/3

不需检查，如果t2.Street是！= ''，因为t1.Street == t2.Street