一、SQL 存儲過程之遊標
--- 使用遊標循環 SQL 查詢結果:
--- 聲明變量
DECLARE @bid nvarchar(30);
DECLARE @address nvarchar(50);
--- 定義遊標
DECLARE cur CURSOR for
select bid,[Address] from building;
--- 打開遊標
OPEN cur
FETCH cur INTO @bid, @address
WHILE @@FETCH_STATUS=0 --- 遊標狀態
BEGIN
print @bid + ', ' + @address
update B_LDZ set CZWDZ = @address where BID = @bid
FETCH cur INTO @bid, @address --- 移到下一位置
END
CLOSE cur --- 關閉遊標
DEALLOCATE cur --- 刪除遊標
二、SQL 解析字符串列表
2.1 遍歷字符串列表
--- SET @s='appNum1,appNum2,appNum3,appNum4,appNum5,appNum6,appNum7,appNum8,'
CREATE PROCEDURE [dbo].[pro_split_str]
@s nvarchar(1000)
AS
BEGIN
DECLARE @bid nvarchar(30)
SET @s= 'appNum1,appNum2,appNum3,appNum4,appNum5,appNum6,appNum7,appNum8,'
WHILE CHARINDEX(',',@s)>0
BEGIN
SET @bid = LEFT(@s,CHARINDEX(',',@s)-1)
print @bid --- 輸出分隔內容,執行SQL或存儲過程
SET @s=RIGHT(@s,LEN(@s)-CHARINDEX(',',@s))
END
END
GO
2.2 存儲過程之 IN 參數
2.2.1 CHARINDEX 分隔字符串
--- 聲明臨時表及參數
declare @TempTable Table(id nvarchar(10),name int)
declare @s nvarchar(100)
set @s = 'a,b'
--- 添加數據
insert @TempTable select 'a',1 union all select 'b',2
union all select 'c',5 union all select 'd',8
--- 檢索數據,相當於 where id in @s
select * from @TempTable where CHARINDEX(','+id+',',','+@s+',')>0
/*
id name
a 1
b 2
*/
2.2.2 創建函數分隔字符串
--- 把含分隔符的字符串轉換爲表
--- @str = 'a,b,c,d'
CREATE FUNCTION [dbo].[Split]
(
@str VARCHAR(MAX) ,
@split VARCHAR(50)
)
RETURNS @t TABLE ( col VARCHAR(50) )
AS
BEGIN
WHILE ( CHARINDEX(@split, @str) <> 0 )
BEGIN
INSERT @t( col )
VALUES ( SUBSTRING(@str, 1, CHARINDEX(@split, @str) - 1) )
SET @str = STUFF(@str, 1, CHARINDEX(@split, @str), '')
END
INSERT @t( col ) VALUES ( @str )
RETURN
END
--- 測試
select * from dbo.split('a,b,c,d' , ',')
/*
col
-----
a
b
c
d
*/
應用時使用:select * from table where id in dbo.split('a,b,c')