SQLSERVER存储过程基础

1.声明变量

DECLARE @F001 SMALLINT, (三元素，声明declare+变量名+类型)

@F002 INTEGER,

@F003 VARCHAR(20),

@F004 CHAR(20),

@@F002 MONEY

2.赋值语句

SET @F001 =space(40) @F002= 3

3.条件判断(IF...ELSE)

IF condition BEGIN

[statements ]

END

ELSE BEGIN (ELSE IF condition2 BEGIN)

[elseifstatements ]

END

4.多分支判断(case[when...then...else...] end）

SET @F011 =

CASE

WHEN [testexpression1] THEN @F001

WHEN [testexpression2] THEN @F002

WHEN [testexpression3] THEN @F003

WHEN [testexpression4] THEN @F004

END

5.循环(while)

WHILE condition BEGIN

[statements ]

END

6.动态定义游标(*)

DECLARE @strSQL nvarchar(30)

DECLARE @inSQL nvarchar(50) -- select...

SET @strSQL = ' DECLARE name_cursor CURSOR FOR
' + @inSQL

EXEC (@strSQL)

7.遍历游标

FETCH NEXT FROM name_cursor into@F001,@F002 （要求与游标的返回值对应）

WHILE @@FETCH_STATUS = 0 BEGIN （如@inSQL是selectf001,f002 from tablename)

FETCH NEXT FROM name_cursor into @F001,@F002

END (说明：FETCH_STATUS检索到数据返回0，失败返回-1，可判断是否滚动未到结尾。)

8.获得游标行数

SET @RECCNT = @@ROWCOUNT --内嵌参数@@FETCH_STATUS
同

9.事务处理

BEGIN distributed transaction

WHILE @@TRANCOUNT > 0

commit transaction

10.字符串连接

SET @m_sql = @m_sql + ' Where F001 = ''' +@F001 + ''''

SET @m_sql = @m_sql + ' F002 = ' + CONVERT(varchar,@F002) convert会加引号？

11.存储过程的调用及返回值

（1）存储过程的创建 (sql server数据库中create procedure)

CREATE PROCEDURE material_solo_days_proc

(@materialnovarchar(20),

@year_month datetime,

@totalday int,

@qty decimal(18,4)=0 output
--总量,也会return

)

BEGIN

DECLARE@@count
int

SET@@count = 0

DECLARE@@dailyqty
decimal(18,4)

SET@@dailyqty
= 0

SET@qty = 0

WHILE@@count < @totalday

BEGIN

--计算日流水量

EXECUTE @@dailyqty
= material_solo_oneday_proc @materialno,@year_month

SET @qty
= @qty + @@dailyqty

SET @year_month
= dateadd(dd,1,@year_month)

SET @@count
= @@count + 1

END

RETURN@qty

END

（2）SQL-DELPHI调用存储过程(open/execproc)

withmaterial_account_proc do

begin

Close;

ProcedureName:='material_account_proc';

Parameters.Clear;

Parameters.Refresh;

Parameters.ParamByName('@year_month').Value:= year_month;

Parameters.ParamByName('@condition').Value:= ''; //string不匹配nvarchar

open;

y :=Parameters.ParamByName('@count').Value;

x := Parameters.ParamByName('@totalday').Value;

end;

（3）存储过程调用存储过程

DECLARE @C001 VARCHAR(20),

@C002 SMALLINT

EXEC name_produce @C001,@C002 output

/////////////////////////////////////////////////////////////////////////////////

12.动态sql语句的创建和执行()

CREATE PROCEDURE usp_GetSalesHistory

　　(

　　 @WhereClauseNVARCHAR(2000)=NULL

　　)

　　BEGIN

　　DECLARE @SelectStatement NVARCHAR(2000)

　　DECLARE @FullStatement NVARCHAR(4000)

　　SET @SelectStatement = 'SELECT * FROM SalesHistory'

　　SET @FullStatement = @SelectStatement +ISNULL(@WhereClause,' ')

　　PRINT @FullStatement

　　EXECUTE sp_executesql @FullStatement

　　/*EXECUTE(@FullStatement) */

END

说明: sp_executesql
执行的不能是varchar只能是nvarchar，sp_executesql
支持独立于 Transact-SQL
字符串设置参数值，有更多例子网上搜。

Execute可以是varchar,而且execute的sql语句中的参数只能是属性列或者表

13.Update语句常见错误总结 (update .,.set where)

--√

Update name_table set

F001 = @F181,

F002 = @F182

Where

F003 = @F003

--×

Update name_table

F001 = @F181,

F002 = @F182

Where

F003 = @F003

--×

Update name_table set

F001 = @F181,

F002 = @F182,

Where

F003 = @F003

--×

Update name_table set

,F001 = @F181

,F002 = @F182

Where

F003 = @F003

14.Insert语句常见语法错误总结

--√

INSERT INTO name_table(

,KEY_FIELD，BUSYOCD

)Values(

@F001,@F002

)

--×

INSERT INTO name_table(

F001,F002

)Values(

,@F001,@F002

)

--×

INSERT INTO name_table(

F001,F002

)Values(

@F001,@F002,

)

--×

INSERT name_table(

F001,F002

)Values(

@F001,@F002

)