Stored procedure (Stored Procedure) using (c)

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 Following The second, followed by the stored procedure used to achieve other functions

Seven string split:

       If only one stored procedure parameter is nvarchar or varchar like string type, if a plurality of strings, this stored procedure to be invoked multiple times, so that the database is connected to a plurality of times, less efficient, it can be composed of a plurality of strings string, signed and spaced apart, and the string stored in the resolution process, then other operations, so that only one call a stored procedure, of course, higher efficiency than the multiple calls. The following is how to split the string (strings are separated by commas):

-- ============================================= -- Author: masson -- Create date: 2009-12-14 -- Description: 拆分字符串 -- ============================================= CREATE PROCEDURE testSplit @Name nvarchar(max) --字符串用逗号分隔 AS declare @charind int,@lengh int declare @NameStr nvarchar(300) BEGIN set @charind = charindex(',',@Name) –-分隔符位置 while @charind >0 –- 大于0表示存在此分隔符 BEGIN set @lengh = len(@Name) –- 字符串总长度 set @NameStr = left(@Name,@charind-1) –-取得一个字符串，@charind-1表示除去分隔符 print @NameStr –- 输出信息 set @Name = right(@Name,@lengh - @charind) –减去已经取得的字符串 set @charind = charindex(',', @Name) --移动下标 if(@charind =0) ––处理最后一个字符串 BEGIN print @NameStr–- 输出信息 END END END

 

Process explain: string found @Name the first separator " , " position, in SQL , the position of the string from a beginning (to the C # open start difference string position). This string is then pre-separator removed, this string is the first string required string @Name subtracting the string has been made and delimiters. In this way, re-string the string has been subtracted made to operate continuously repeated. Until the last character string, this string is not delimiter, the string itself is the need to take.

Here a few functions to explain:

( . 1 ) CHARINDEX ( separator, string ) : obtaining a first position designation delimiter in the string. Return int , such as string, "ABC, EFG, HIJ" , calls CHARINDEX ( ',', 'ABC, EFG, HIJ' ), returns 4 . If there is no matching delimiters, it returns 0.

( 2 ) left ( string, left N characters ) , returns this string from left N characters. Such as call left (ABCDEFG, 3) , then returns abc

    ( . 3 ) right (( string, from right N characters ) , returns this string from right N characters as call right (ABCDEFG,. 3) , is returned EFG .

 

Eight randomly selected table records:

       If you need to select from a table of random N records are returned, the need to use Order by NEWID () . The following format:

select top N * from tableName order by newid()。

       Note that, here, N is a number has been determined, i.e., before the call has been determined N value. * Represent the columns you want to select, you can add where statements were randomly selected in the qualifying line. As shown, from the following A random selection of Table 2 records that meet the conditions of Article:

 

-- ============================================= -- Author: masson -- Create date: 2009-12-14 -- Description: 随机选择1 -- ============================================= CREATE PROCEDURE testNewid @name nvarchar(20) AS BEGIN select TOP 2 * from A where Name = @name order by newid() END

    If N is the SQL query out by other tables to determine the value, you can put in a variable written statement, to be N to determine and then execute it, as shown below.

-- ============================================= -- Author: masson -- Create date: 2009-12-14 -- Description: 随机选择2 -- ============================================= CREATE PROCEDURE testNewid @name nvarchar(20) AS declare @s nvarchar(max), @n int BEGIN Select @n = Num from B where Name=@name -- 取得数量N set @s = ' select top '+cast(@n as nvarchar(50))+ ' * from A where Name=’ +@name + ‘ order by newid() '—把select语句写在变量中 exec (@s) – 执行 END

Nine of temporary table:

       If you need to check out a bunch of records, and then take the data records from the heap, then use the temporary table is a good choice. Create a temporary table, the table name needs to add " # ." The format is:

create table #t ( parameter name parameter type ) , the following are examples, the table A , table B , table C in the name of the query are out on the temporary table, and then remove all the temporary table name.

-- ============================================= -- Author: masson -- Create date: 2009-12-14 -- Description: 临时表 -- ============================================= CREATE PROCEDURE testTempTable AS BEGIN Select @n = Num from B where Name=@name -- 取得数量N set @s = create table #t(name varchar())’ +' insert into #t select Name from A '+' insert into #t select Name form B ’ +' insert into #t select Name form C ’ +' select * from #t’—-把语句写在变量中 exec (@s) – 执行,返回临时表中的全部记录 END

 

   至此，已经将所用到的使用存储过程的功能使用进行了介绍，希望可以帮到初学者，同时也可以记录一下自己学习的过程。呵呵