Question

╔════╦══════╦════════════╗
║ ID ║ NAME ║    WORK    ║
╠════╬══════╬════════════╣
║  1 ║ a    ║ complete   ║
║  1 ║ a    ║ complete   ║
║  2 ║ b    ║ incomplete ║
║  3 ║ c    ║ complete   ║
║  4 ║ d    ║ incomplete ║
║  4 ║ d    ║ complete   ║
║  5 ║ e    ║ complete   ║
║  5 ║ e    ║ complete   ║
║  5 ║ e    ║ incomplete ║
║  6 ║ f    ║ incomplete ║
║  6 ║ f    ║ incomplete ║
╚════╩══════╩════════════╝

我想构建一个查询，该查询只检索所有作业完成或单个不完整的ID

例如在上面的数据中，我想只得到这些id

1, 2, 3, 4, 5

不是6因为它有多个不完整的作品

Answer 1

SELECT  ID, Name
FROM    tableName
GROUP   BY ID, NAME
HAVING  SUM(CASE WHEN Work = 'Incomplete' THEN 1 ELSE 0 END) < 2

SQLFiddle Demo

Answer 2

您应该可以使用NOT EXISTS执行此类操作：

SELECT DISTINCT H.ID
FROM Homework H
WHERE H.Work = 'Complete'
   AND NOT EXISTS (
        SELECT * 
        FROM Homework H2 
        WHERE H2.Work != 'Complete' AND H2.ID = H.ID )

这是SQL Fiddle。

编辑 - 实际上，只是注意到你也想要那些只有一个不完整的东西 - 让我编辑。应该这样做：

SELECT DISTINCT H.ID
FROM Homework H
GROUP BY H.ID
HAVING COUNT(*) = 1 OR (
  NOT EXISTS (
    SELECT * 
    FROM Homework H2 
    WHERE H2.Work != 'Complete' 
      AND H2.ID = H.ID ))

更多小提琴：http://sqlfiddle.com/#!3/c7d43e/3

祝你好运。

使用此数据查询构建

2 个答案: