Question

我想处理嵌套案例：

SELECT *, 
    GROUP_CONCAT(DISTINCT CONCAT(
    CASE
      WHEN data.name NOT "field" THEN   
        CASE
          WHEN data.category = "A" THEN "A"
          WHEN data.category = "B" THEN "B"
          ELSE "C"
        END,data.name
    END
   )ORDER BY FIND_IN_SET(data.category,"B,C,A") ASC, data.name ASC SEPARATOR " <br>") AS result
  FROM data;');

但是我收到一条错误消息：

致命错误：未捕获PDOException：SQLSTATE [42000]：语法错误或访问冲突：1064您的SQL语法有错误;检查手册，对应右边的MySQL服务器版本在＆＃39; data.name END＆＃39;附近使用的语法在第11行

Answer 1

您的查询中存在一些语法错误。在查询编辑器中运行以下代码，它就可以了。

SELECT 
 *,
GROUP_CONCAT(
DISTINCT CONCAT(
  CASE
    WHEN data.name = "field" 
    THEN (
      CASE
        WHEN data.category = "A" 
        THEN "A" 
        WHEN data.category = "B" 
        THEN "B" 
        ELSE "C" 
      END
    ) 
  END,
    data.name
) 
ORDER BY FIND_IN_SET(data.category, "B,C,A") ASC,
data.name ASC SEPARATOR " <br>"
) AS result 
 FROM DATA;

如何在mySQL中使用嵌套案例？

1 个答案: