mysql - mysql中结果集的情况

Question

我想在 mysql 中测试以下查询

SELECT result.* FROM 
(CASE WHEN (2 = 2) 
THEN
(SELECT * FROM mytable WHERE myID =2814 )
END) result ;

但发送语法错误。知道有什么问题吗？

Answer 1

你可以像这样迂回地做到这一点

SET @query := NULL;

SELECT @query := t.qry 
FROM 
(   SELECT 
        CASE WHEN 2 = 2
             THEN "SELECT * FROM mytable WHERE myID =2814"
             WHEN another_condition
             THEN "another_select"
        END as qry
) t ;

PREPARE query1 FROM @query;
EXECUTE query1;