常用sql语句整理[SQL Server]

1. 存储过程

CREATE PROCEDURE [dbo].[bbs_move_createtopic]
@fid smallint,
@iconid smallint,
@curtid INT OUTPUT
AS
BEGIN
    INSERT INTO [topics] ......
    SET @topicid=SCOPE_IDENTITY()
END

declare @curtid int
exec [createtopic] @fid=@new_fid,@iconid=0,
    @curtid=@curr_topicid OUTPUT

2. 游标

    DECLARE
        @name NVARCHAR(100),
        @id DECIMAL,
        @idcard NVARCHAR(100)=NULL
    
    --声明游标
    DECLARE cur_correctIdCard CURSOR
    FOR
    SELECT 
    ID, NAME, [USER_ID]
    FROM dbo.old_bbstitle 
    WHERE (USER_ID IS NULL OR LTRIM(NAME)='') 
    OR (NAME IS NULL OR LTRIM(NAME)='')
    --打开游标
    OPEN cur_correctIdCard
    --开始FETCH
    FETCH NEXT FROM cur_correctIdCard INTO @id,@name,@idcard
    
    --0 FETCH 语句成功
    --1 FETCH 语句失败或此行不在结果集中
    --2 被提取的行不存在
    WHILE(@@FETCH_STATUS=0) 
    BEGIN
        ... ...
        
        FETCH NEXT FROM cur_correctIdCard INTO @id,@name,@idcard
        SET @idcard=NULL
    END
    
    CLOSE cur_correctIdCard
    DEALLOCATE cur_correctIdCard

3. 复制表的数据

SELECT * INTO users_bak FROM users

4. group by … having …

DELETE
FROM dbo.old_clubuser WHERE CLUBUSER_ID
IN(
SELECT MIN(CLUBUSER_ID) FROM dbo.old_clubuser WHERE CLUBUSER_NAME IS NOT NULL AND CLUBUSER_NICKNAME IS NOT NULL
GROUP BY CLUBUSER_NAME,CLUBUSER_NICKNAME
HAVING COUNT(CLUBUSER_NAME)>1
)

5. 事务

BEGIN TRANSACTION trans_correctIdCard
BEGIN TRY
    DECLARE
        @name NVARCHAR(100),
        @id DECIMAL,
        @idcard NVARCHAR(100)=NULL

    COMMIT TRANSACTION trans_correctIdCard
    PRINT 'SUCCESS'
END TRY
BEGIN CATCH
    
    ROLLBACK TRANSACTION trans_correctIdCard
    
    PRINT '出错：'+CAST(@@error AS NVARCHAR(MAX))
    PRINT '已进行回滚'

END CATCH

5. 先判断表是否存在再创建表

--判断表是否存在，存在则先删除
IF object_id(N'dbo.T_Student',N'U') IS NOT NULL
DROP TABLE dbo.T_Student
GO

--创建表
CREATE TABLE [dbo].[T_Student](
 [Id] [int] IDENTITY(1,1) NOT NULL,
 [Name] [nvarchar](max) NULL,
 [Age] [int] NOT NULL,
 [NickName] [nvarchar](max) NULL,
 [City] [nvarchar](max) NULL,
 CONSTRAINT [PK_dbo.T_Student] PRIMARY KEY CLUSTERED ([Id] ASC)
)

6. 获取SQL Server表结构

SELECT (case when a.colorder=1 then d.name else null end) 表名,  
a.colorder 字段序号,a.name 字段名,
(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) 标识, 
(case when (SELECT count(*) FROM sysobjects  
WHERE (name in (SELECT name FROM sysindexes  
WHERE (id = a.id) AND (indid in  
(SELECT indid FROM sysindexkeys  
WHERE (id = a.id) AND (colid in  
(SELECT colid FROM syscolumns WHERE (id = a.id) AND (name = a.name)))))))  
AND (xtype = 'PK'))>0 then '√' else '' end) 主键,b.name 类型,a.length 占用字节数,  
COLUMNPROPERTY(a.id,a.name,'PRECISION') as 长度,  
isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as 小数位数,(case when a.isnullable=1 then '√'else '' end) 允许空,  
isnull(e.text,'') 默认值,isnull(g.[value], ' ') AS [说明]
FROM  syscolumns a 
left join systypes b on a.xtype=b.xusertype  
inner join sysobjects d on a.id=d.id and d.xtype='U' and d.name<>'dtproperties' 
left join syscomments e on a.cdefault=e.id  
left join sys.extended_properties g on a.id=g.major_id AND a.colid=g.minor_id
left join sys.extended_properties f on d.id=f.class and f.minor_id=0
where b.name is not null
--WHERE d.name='要查询的表' --如果只查询指定表,加上此条件
order by a.id,a.colorder

（出处：http://www.cnblogs.com/ynbt/archive/2012/07/16/2593389.html）

7. 查询数据库中的所有数据库名

SELECT Name FROM Master..SysDatabases ORDER BY Name

8. 查询某个数据库中所有的表名

SELECT Name FROM SysObjects Where XType='U' ORDER BY Name

9. 批量清空一个库的表（1）

SELECT 'TRUNCATE TABLE ' + Name FROM SysObjects Where XType='U' ORDER BY Name

10. 批量清空一个库的表（2）

    USE [库名]
    DECLARE
        @tableName NVARCHAR(100)
    
    --声明游标
    DECLARE CUR_ALLTABLES CURSOR
    FOR
    SELECT Name FROM SysObjects Where XType='U' ORDER BY Name

    --打开游标
    OPEN CUR_ALLTABLES
    --开始FETCH
    FETCH NEXT FROM CUR_ALLTABLES INTO @tableName
    
    DECLARE @SQL VARCHAR(MAX) = ''

    --0 FETCH 语句成功
    --1 FETCH 语句失败或此行不在结果集中
    --2 被提取的行不存在
    WHILE(@@FETCH_STATUS=0) 
    BEGIN
        
        SET @SQL = 'TRUNCATE TABLE ' + @tableName
        PRINT @SQL

        FETCH NEXT FROM CUR_ALLTABLES INTO @tableName
    END
    
    CLOSE CUR_ALLTABLES
    DEALLOCATE CUR_ALLTABLES

 11. 行列转换的例子

WITH CTE AS (
    select 1 as 序号 ,'2010-2-3' as 日期,'是' as 状
    union all
    select 2 as 序号 ,'2010-2-3' as 日期,'否' as 状
    union all
    select 3 as 序号 ,'2010-2-4' as 日期,'是' as 状
    union all
    select 4 as 序号 ,'2010-2-4' as 日期,'否' as 状
    union all
    select 5 as 序号 ,'2010-2-3' as 日期,'是' as 状
    union all
    select 6 as 序号 ,'2010-2-3' as 日期,'是' as 状
    union all
    select 7 as 序号 ,'2010-2-4' as 日期,'是' as 状
)
SELECT 日期, SUM(是) 是, SUM(否) 否 FROM (
    SELECT 日期, 
    CASE WHEN 状='是' THEN 1 ELSE 0 END AS 是,
    CASE WHEN 状='是' THEN 0 ELSE 1 END AS 否 FROM CTE
)A GROUP BY 日期

12. 获取一个存储过程的内容

DECLARE @Content NVARCHAR(max)
SELECT @Content=text
FROM syscomments
WHERE id = ( SELECT id FROM sysobjects WHERE name = 'StoredProcedureName') 
PRINT @Content

13. 使用OFFSET/FETCH NEXT获取分页数据[SQL Server 2012]
注：OFFSET是从0开始的

DECLARE @Count int = 10
SELECT * FROM TableName(NOLOCK) WHERE Status&2=2
ORDER BY CreateTime DESC
OFFSET 0 ROW FETCH NEXT @Count rows only

14. top

DECLARE @COUNT INT = 10;
SELECT TOP(@COUNT) FROM T_Name

 15. Create View

IF object_id(N'dbo.v_users',N'V') IS NOT NULL
    DROP VIEW dbo.v_users
GO

CREATE VIEW dbo.v_users
AS
SELECT *
FROM [dbo].[users]

 16. 查看SP

sp_helptext spname

 17. 获取执行统计信息

DBCC DROPCLEANBUFFERS 清除缓冲区
DBCC FREEPROCCACHE 删除计划高速缓存中的元素


SET STATISTICS TIME ON
SET STATISTICS IO ON

SELECT 1 FROM Persons

SET STATISTICS TIME OFF
SET STATISTICS IO OFF

相关： http://www.cnblogs.com/xqhppt/p/4041799.html

18. 修改字段

alter table Persons alter column Name nvarchar(12) not null

To Be Continued ...