mysql - 将 MySQL 转换为 SQL Server

Question

我正在尝试运行以下查询(针对 Foodmart 2000)，它在 MySQL 上运行良好。在 SQL Server 2005 上，我得到的只是一条“Syntax error close '”消息。

SELECT * FROM ((SELECT COUNT(state_province) AS 'WA'
                FROM customer c1
                WHERE c1.state_province LIKE 'WA'
                GROUP BY c1.state_province) as t1,
               (SELECT COUNT(state_province) AS 'OR'
                FROM customer c1
                WHERE c1.state_province LIKE 'OR'
                GROUP BY c1.state_province) as t2,
               (SELECT COUNT(state_province) AS 'CA'
                FROM customer c1
                WHERE c1.state_province LIKE 'CA'
                GROUP BY c1.state_province) as t3); 

到底是什么导致了这个问题？

Answer 1

您缺少别名:

SELECT * 
FROM 
(
  select *
  from 
  (SELECT COUNT(state_province) AS 'WA'
   FROM customer c1
   WHERE c1.state_province LIKE 'WA'
   GROUP BY c1.state_province) as t1,
  (SELECT COUNT(state_province) AS 'OR'
   FROM customer c1
   WHERE c1.state_province LIKE 'OR'
   GROUP BY c1.state_province) as t2,
   (SELECT COUNT(state_province) AS 'CA'
    FROM customer c1
    WHERE c1.state_province LIKE 'CA'
    GROUP BY c1.state_province) as t3
) src;  -- < add this alias

您必须在所有派生表和子查询上都有别名。

您还可以通过使用以下命令来使用 @Kaf 的 still 版本和 count:

SELECT count(CASE WHEN state_province LIKE 'WA' THEN 1 ELSE null END) AS 'WA',
       count(CASE WHEN state_province LIKE 'OR' THEN 1 ELSE null END) AS 'OR',
       count(CASE WHEN state_province LIKE 'CA' THEN 1 ELSE null END) AS 'CA'
FROM customer

参见SQL Fiddle with Demo