mysql - 从表中选择值作为新列

Question

帮我处理一下sql

我这里有一张 table : click here to see table

我想添加一个新行像这样“first name”

meta_key = first_name 和对应的meta_value基本看起来像这样

first name----------arnoldgearjohndude

Answer 1

尝试

SELECT MIN(CASE WHEN meta_key = 'first_name' THEN meta_value END) first_name,
       MIN(CASE WHEN meta_key = 'last_name'  THEN meta_value END) last_name
  FROM wp_usermeta
 WHERE meta_key IN ('first_name','last_name')
 GROUP BY user_id

示例输出:

| FIRST_NAME |  LAST_NAME |---------------------------|    Patrice | Fitzgerald ||       Jhon |        Doe ||       Mark |     (null) |

这里是SQLFiddle 演示