如何在sql

Question

如何在sql中执行if和join语句，如：

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

sqlfiddle

我想要的只是在街道上加入！=＆＃39; ＆＃39;

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 != ' ')

将条件添加到联接

Answer 2

您可以在where条件下执行此操作。

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

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

不需要检查t2.Street是否！=''因为t1.Street == t2.Street