如何在MySQL查询中编写IF ELSE语句

Question

如何在MySQL查询中编写IF ELSE语句？

像这样：

mysql_query("...(irrelevant code).. IF(action==2&&state==0){state=1}");

然后在我的数组中，我应该能够做到这一点：

 $row['state'] 
//this should equal 1, the query should not change anything in the database, 
//just the variable for returning the information

Answer 1

您可能要使用CASE表达式。

他们看起来像这样：

SELECT col1, col2, (case when (action = 2 and state = 0) 
 THEN
      1 
 ELSE
      0 
 END)
 as state from tbl1;