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SQL Server插入（如果不存在）

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我想在我的表中插入数据，但只插入我的数据库中不存在的数据！

这是我的代码：

ALTER PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
AS
BEGIN
   INSERT INTO EmailsRecebidos (De, Assunto, Data)
   VALUES (@_DE, @_ASSUNTO, @_DATA)
   WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA);
END

错误是：

消息156，级别15，状态1，过程EmailsRecebidosInsert，第11行关键字'WHERE'附近的语法不正确 .

sql sql-server sql-server-2008 stored-procedures

9 回答

  • 7

    试试下面的代码

    ALTER PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
AS
BEGIN
   INSERT INTO EmailsRecebidos (De, Assunto, Data)
   select @_DE, @_ASSUNTO, @_DATA
   EXCEPT
   SELECT De, Assunto, Data from EmailsRecebidos
END
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  • 213

    而不是代码

    BEGIN
   INSERT INTO EmailsRecebidos (De, Assunto, Data)
   VALUES (@_DE, @_ASSUNTO, @_DATA)
   WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA);
END

    用 . . . 来代替

    BEGIN
   IF NOT EXISTS (SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA)
   BEGIN
       INSERT INTO EmailsRecebidos (De, Assunto, Data)
       VALUES (@_DE, @_ASSUNTO, @_DATA)
   END
END

    Updated : （感谢@Marc Durdin指点）

    请注意，在高负载下，这仍然有时会失败，因为第二个连接可以在第一个连接执行INSERT之前通过IF NOT EXISTS测试，即竞争条件 . 请参阅stackoverflow.com/a/3791506/1836776以获得有关为什么即使在事务中包装也无法解决此问题的答案 .

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  • 9

    对于那些寻找最快速方式的人来说，我最近came across these benchmarks显然使用"INSERT SELECT... EXCEPT SELECT..."成为5000万或更多记录中最快的 .

    这是文章中的一些示例代码（第3块代码是最快的）：

    INSERT INTO #table1 (Id, guidd, TimeAdded, ExtraData)
SELECT Id, guidd, TimeAdded, ExtraData
FROM #table2
WHERE NOT EXISTS (Select Id, guidd From #table1 WHERE #table1.id = #table2.id)
-----------------------------------
MERGE #table1 as [Target]
USING  (select Id, guidd, TimeAdded, ExtraData from #table2) as [Source]
(id, guidd, TimeAdded, ExtraData)
    on [Target].id =[Source].id
WHEN NOT MATCHED THEN
    INSERT (id, guidd, TimeAdded, ExtraData)
    VALUES ([Source].id, [Source].guidd, [Source].TimeAdded, [Source].ExtraData);
------------------------------
INSERT INTO #table1 (id, guidd, TimeAdded, ExtraData)
SELECT id, guidd, TimeAdded, ExtraData from #table2
EXCEPT
SELECT id, guidd, TimeAdded, ExtraData from #table1
------------------------------
INSERT INTO #table1 (id, guidd, TimeAdded, ExtraData)
SELECT #table2.id, #table2.guidd, #table2.TimeAdded, #table2.ExtraData
FROM #table2
LEFT JOIN #table1 on #table1.id = #table2.id
WHERE #table1.id is null
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  • 6

    我会使用合并：

    create PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
AS
BEGIN
   with data as (select @_DE as de, @_ASSUNTO as assunto, @_DATA as data)
   merge EmailsRecebidos t
   using data s
      on s.de = t.de
     and s.assunte = t.assunto
     and s.data = t.data
    when not matched by target
    then insert (de, assunto, data) values (s.de, s.assunto, s.data);
END
    回复于
  • 21

    INSERT 命令没有 WHERE 子句 - 您必须像这样编写它：

    ALTER PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
AS
BEGIN
   IF NOT EXISTS (SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA)
   BEGIN
       INSERT INTO EmailsRecebidos (De, Assunto, Data)
       VALUES (@_DE, @_ASSUNTO, @_DATA)
   END
END
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  • 42

    我用SQL SERVER 2012做了同样的事情并且它起作用了

    Insert into #table1 With (ROWLOCK) (Id, studentId, name)
SELECT '18769', '2', 'Alex'
WHERE not exists (select * from #table1 where Id = '18769' and studentId = '2')
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  • 0

    除了IF EXISTS之外，您还可以使用MERGE，具体取决于您的SQL Server版本（2012？）：

    ALTER PROCEDURE [dbo].[EmailsRecebidosInsert]
    ( @_DE nvarchar(50)
    , @_ASSUNTO nvarchar(50)
    , @_DATA nvarchar(30))
AS BEGIN
    MERGE [dbo].[EmailsRecebidos] [Target]
    USING (VALUES (@_DE, @_ASSUNTO, @_DATA)) [Source]([De], [Assunto], [Data])
         ON [Target].[De] = [Source].[De] AND [Target].[Assunto] = [Source].[Assunto] AND [Target].[Data] = [Source].[Data]
     WHEN NOT MATCHED THEN
        INSERT ([De], [Assunto], [Data])
        VALUES ([Source].[De], [Source].[Assunto], [Source].[Data]);
END
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  • 0

    您可以使用GO命令 . 这将在发生错误后重新启动sql语句的执行 . 在我的情况下，我有几个1000 INSERT语句，其中少数这些记录已存在于数据库中，我只是不知道哪些 . 我发现在处理了几个100之后，执行只是因为记录已经存在而无法INSERT的错误消息而停止 . 相当讨厌，但是把GO解决了这个问题 . 它可能不是最快的解决方案，但速度不是我的问题 .

    GO
INSERT INTO mytable (C1,C2,C3) VALUES(1,2,3)
GO
INSERT INTO mytable (C1,C2,C3) VALUES(4,5,6)
 etc ...
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  • 17

    As explained in below code: 执行以下查询并验证自己（它们是不言自明的）

    CREATE TABLE `table_name` (
  `id` int(11) NOT NULL auto_increment,
  `name` varchar(255) NOT NULL,
  `address` varchar(255) NOT NULL,
  `tele` varchar(255) NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=InnoDB;

    插入记录：

    INSERT INTO table_name (name, address, tele)
SELECT * FROM (SELECT 'Nazir', 'Kolkata', '033') AS tmp
WHERE NOT EXISTS (
    SELECT name FROM table_name WHERE name = 'Nazir'
) LIMIT 1;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0

SELECT * FROM `table_name`;

+----+--------+-----------+------+
| id | name   | address   | tele |
+----+--------+-----------+------+
|  1 | Nazir  | Kolkata   | 033  |
+----+--------+-----------+------+

    现在，尝试再次插入相同的记录：

    INSERT INTO table_name (name, address, tele)
SELECT * FROM (SELECT 'Nazir', 'Kolkata', '033') AS tmp
WHERE NOT EXISTS (
    SELECT name FROM table_name WHERE name = 'Nazir'
) LIMIT 1;

Query OK, 0 rows affected (0.00 sec)
Records: 0  Duplicates: 0  Warnings: 0

+----+--------+-----------+------+
| id | name   | address   | tele |
+----+--------+-----------+------+
|  1 | Nazir  | Kolkata   | 033  |
+----+--------+-----------+------+

    插入不同的记录：

    INSERT INTO table_name (name, address, tele)
SELECT * FROM (SELECT 'Santosh', 'Kestopur', '044') AS tmp
WHERE NOT EXISTS (
    SELECT name FROM table_name WHERE name = 'Santosh'
) LIMIT 1;

Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0

SELECT * FROM `table_name`;

+----+--------+-----------+------+
| id | name   | address   | tele |
+----+--------+-----------+------+
|  1 | Nazir  | Kolkata   | 033  |
|  2 | Santosh| Kestopur  | 044  |
+----+--------+-----------+------+
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