如何寫，如果和連接語句在SQL

Question

我如何既如果執行和連接語句在SQL這樣的：

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

sqlfiddle

我想是加入只有兩個街道='！ '

謝謝！

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 != ' ') 

加入條件的加入

Answer 2

您可以用where條件做到這一點。

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

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

不需檢查，如果t2.Street是！= ''，因爲t1.Street == t2.Street