Question

感谢您在Advance中的所有帮助。

我在MySQL PHPmyAdmin中有一个名为'data'的表，就像这样;

Primary | Date| User | Response
   1      Mon   Tom      Yes
   2      Mon   Terry    No
   3      Mon   Lucas    Yes
   4      Tue   Tom      No
   5      Tue   Terry    No
   6      Tue   Lucas    Yes
   7      Wed   Tom      Yes
   8      Wed   Terry    Yes
   9      Wed   Lucas    No

如何通过最可能的SQL查询或Pivot / php数组输出到表中，以便为HTML表输出做好准备;

Date | Tom | Terry | Lucas
Mon    Yes   No      Yes
Tue    No    No      Yes
Wed    Yes   Yes     No

Answer 1

SELECT  Date,
        MAX(CASE WHEN user = 'Tom' THEN Response ELSE NULL END) Tom,
        MAX(CASE WHEN user = 'Terry' THEN Response ELSE NULL END) Terry ,
        MAX(CASE WHEN user = 'Lucas' THEN Response ELSE NULL END) Lucas
FROM    tableName
GROUP   BY Date

SQLFiddle Demo

如果您的days数量未知，则更喜欢动态SQL，

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'MAX(case when user = ''',
      user,
      ''' then Response end) AS ',
      user
    )
  ) INTO @sql
FROM tableName;

SET @sql = CONCAT('SELECT  Date, ', @sql, ' 
                  FROM    tableName
                  GROUP   BY Date');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SQLFiddle Demo

SQL查询：行到列转动到PHP数组/ HTML输出

1 个答案: