C# SQL INSERT INTO 查询并显示结果

Question

我正在使用 VS2005 和 SQL Server 2005。

我正在尝试执行连接 3 个 sql 表的多个 INSERT INTO SQL 语句。

这三个表是：

• Table1: UserID, Username
• Table2: UserID, Status
• Table3: UserID, Username, Issue

以下是我需要执行的检查：

1. 存在于Table1 中的用户应该存在于Table2 中

2. 存在于Table1 中的用户不应在Table2 中拥有STATUS=DELETE

3. Table2 中没有STATUS=DELETE 的用户应该存在于Table1 中

目前我只有一个SELECT 语句满足上述3个查询，没有添加到第三个表：

SELECT *
FROM table1 t1
FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
WHERE (t2.userid IS NULL AND t1.userid IS NOT NULL)
OR (t2.status = 'DELETE' AND t1.userid IS NOT NULL)
OR (t2.userid IS NOT NULL AND t2.status <> 'DELETE' AND t1.userid IS NULL)

我想，对于上述每项检查，INSERT 将结果放入具有唯一 ISSUE 变量的 Table3 中（例如，对于 1 号检查，ISSUE=User exist in t1 but not t2）

目前我正在尝试形成一个将 3 个表连接在一起的查询，对于第一次检查找到的每个结果，t2.userid IS NULL AND t1.userid IS NOT NULL，它将在Table3 中插入一个新行。但是我的 SQL 查询有一些问题。

INSERT INTO Table3 (userid, username, issue) 
VALUES (t1.userid, t1.username, 'user not found in t2')
FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
WHERE (t2.userid IS NULL AND t1.userid IS NOT NULL)

非常感谢您的帮助。

Answer 1

我没有这些表用于测试，所以语法会很接近：

UserId 的 COALESCE 将确保您在列中插入了一个值，因为您不确定该值是否存在于 Table1 或 Table2 中

我还刚刚使用了 CASE 语句的 where 子句来填充 Issue 列。您可以更新文本以适合您的应用程序。

INSERT INTO Table3(UserId, Username, Issue)
SELECT COALESCE(t1.UserId, t2.UserId), t1.UserName
   , CASE
        WHEN (t2.userid IS NULL AND t1.userid IS NOT NULL)
           THEN 'User exists in t1 but not in t2'
        WHEN (t2.status = 'DELETE' AND t1.userid IS NOT NULL)
           THEN 'User Exists in t1, but status in t2 is not DELETE'
        WHEN (t2.userid IS NOT NULL AND t2.status != 'DELETE' AND t1.userid IS NULL)
           THEN 'Non-Deleted user in t2 does not exist in t1'
     END
FROM table1 t1
FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
WHERE (t2.userid IS NULL AND t1.userid IS NOT NULL)
   OR (t2.status = 'DELETE' AND t1.userid IS NOT NULL)
   OR (t2.userid IS NOT NULL AND t2.status != 'DELETE' AND t1.userid IS NULL)

Answer 2

1.
    Insert in to Table3(userid,issue)
        SELECT t1.userid,'check no.1'
        FROM table1 t1
        FULL OUTER JOIN table2 t2 ON t1.userid = t2.userid
        where t1.userid not null and t2.userid is null
2.
    Insert in to Table3(userid,issue)
        SELECT t1.userid,'check no.2'
        FROM table1 t1
        inner JOIN table2 t2 ON t1.userid = t2.userid
        where t2.status = 'DELETE'

3.
    Insert in to Table3(userid,issue)
        SELECT t2.userid,'check no.3'
        FROM table1 t1
        right outer JOIN table2 t2 ON t1.userid = t2.userid
        where t2.status = 'DELETE' and t1.userid is null