SqlServer 游标

找出数据库中所有的数据库名：

　　

DECLARE @databaseName VARCHAR(100)

DECLARE @itemCur CURSOR
SET @itemCur = CURSOR FOR 
    SELECT name FROM sys.databases 
        WHERE database_id > 4

OPEN @itemCur
FETCH NEXT FROM @itemCur INTO @databaseName
--读取下一条游标是否成功
WHILE @@FETCH_STATUS=0
BEGIN
    --逻辑处理
    PRINT @databaseName
    
    FETCH NEXT FROM @itemCur INTO @databaseName
END 

CLOSE @itemCur
DEALLOCATE @itemCur

 

鼠标轨迹字字符串分割：

1.创建测试表

--创建测试表[VisiteLog]
CREATE TABLE [dbo].[VisiteLog](
    [Id] [int] IDENTITY(1,1) NOT NULL,
    [PosSet] [varchar](500) NULL,
 CONSTRAINT [PK_VisiteLog] PRIMARY KEY CLUSTERED 
(
    [Id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

--插入测试数据
SET IDENTITY_INSERT [dbo].[VisiteLog] ON
INSERT [dbo].[VisiteLog] ([Id], [PosSet]) VALUES (1, N'[573,1103,2010-09-03 22:32:35],[864,110,2010-09-03 22:32:57]')
INSERT [dbo].[VisiteLog] ([Id], [PosSet]) VALUES (2, N'[513,1303,2010-09-03 22:34:35]')
SET IDENTITY_INSERT [dbo].[VisiteLog] OFF

--查看数据
SELECT * FROM [dbo].[VisiteLog]

 结果：

2.创建表PosSetInfo，这个表是用来保存鼠标轨迹字符串分割后的数据

--创建表[PosSetInfo]
CREATE TABLE [dbo].[PosSetInfo](
    [ID] [int] NULL,
    [PosSet_x] [int] NULL,
    [PosSet_y] [int] NULL,
    [PosTime] [datetime] NULL
) ON [PRIMARY]
GO

 3.创建了一个函数，它的作用是把字符串@str以@split分隔符进行分隔，返回第@index次匹配的元素。

CREATE FUNCTION [dbo].[Get_StrArrayStrOfIndex]
(
    @str VARCHAR(5000),  --要分割的字符串
    @split VARCHAR(10),  --分隔符号
    @index INT --取第几个元素
)
RETURNS VARCHAR(5000)
AS
BEGIN
    DECLARE @location INT
    DECLARE @start INT
    DECLARE @next INT
    DECLARE @seed INT
    SET @str=LTRIM(RTRIM(@str))
    SET @start=1
    SET @next=1
    SET @seed=LEN(@split)
  
    SET @location=CHARINDEX(@split,@str)
    WHILE @location<>0 and @index>@next
    BEGIN
        SET @start=@location+@seed
        SET @location=CHARINDEX(@split,@str,@start)
        SET @next=@next+1
    END
    IF @location =0 SELECT @location =LEN(@str)+1 
    RETURN SUBSTRING(@str,@start,@location-@start)
END

--测试函数
SELECT DBO.[Get_StrArrayStrOfIndex]('AB,CDE,FG,HIJK',',',3);

 

4.VisiteLog表的数据进行分割，再把分割后的字符串保存到PosSetInfo表中

--鼠标轨迹字符串分割
DECLARE @ID int,@PosSet VARCHAR(2000)
DECLARE @splitlen INT
DECLARE @split NVARCHAR(10)
DECLARE @temp VARCHAR(100)
DECLARE @PosSet_x INT
DECLARE @PosSet_y INT
DECLARE @PosTime DATETIME
SET @split = ']'
DECLARE @itemCur CURSOR
SET @itemCur = CURSOR FOR 
    SELECT ID,PosSet FROM [VisiteLog]
        WHERE PosSet <> ''

OPEN @itemCur
FETCH NEXT FROM @itemCur INTO @ID,@PosSet
WHILE @@FETCH_STATUS=0
BEGIN
    SET @splitlen=LEN(@split+'a')-2
    WHILE CHARINDEX(@split,@PosSet)>0
    BEGIN
        SET @Temp = LEFT(@PosSet,CHARINDEX(@split,@PosSet)-1)
        SET @Temp = replace(replace(@Temp,',[',''),'[','')
        SET @PosSet_x = dbo.Get_StrArrayStrOfIndex(@Temp,',',1)
        SET @PosSet_y = dbo.Get_StrArrayStrOfIndex(@Temp,',',2)
        SET @PosTime = dbo.Get_StrArrayStrOfIndex(@Temp,',',3)
        INSERT PosSetInfo VALUES(@ID,@PosSet_x,@PosSet_y,@PosTime)
        SET @PosSet=STUFF(@PosSet,1,CHARINDEX(@split,@PosSet)+@splitlen,'')
    END

    FETCH NEXT FROM @itemCur INTO @ID,@PosSet
END 

CLOSE @itemCur
DEALLOCATE @itemCur

 5.看PosSetInfo表的数据

SELECT * FROM [dbo].[PosSetInfo]

 

6.补充：

--循环每个数据库
EXEC sp_MSForEachDB 'USE [?];
SELECT * FROM sys.database_files'