SQL server for circular usage

A project needs to be modified recently , involves SqlServer Database knowledge , Sort it out and share it with you , Old rules , Post the example first , Finally, grammar ：

preparation , simulation 2012-2018 Annual order data ：

First from tb_Detail In the order detail table, find out which one belongs to 2012 Years of data （ Remarks yes , Deliberately simulated ）, Find out OrderID：

select OrderID from tb_Detail where Remark = "2012 For annual data ";

Re pass OrderID modify tb_OrderInfo Each year in the commodity order table ：

update tb_OrderInfo set OrderDate="2012-05-31 11:27:37.123" where OrderID in (select OrderID from tb_Detail where Remark = "2012 For annual data ");

Checked the whole 2012 The annual data is OK （select OrderID from tb_OrderInfo where YEAR(OrderDate) =2012;） Consider using for Circulated ：

declare @min int

declare @max int

set @min=2013

set @max=2019

while @min<@max

begin

update tb_OrderInfo set OrderDate=cast(@min as varchar(10))+"-05-31 11:27:37.123" where OrderID in (select OrderID from tb_Detail where Remark = cast(@min as varchar(10))+" For annual data ")

set @[email protected]+1

end

Be careful for In the loop cast(@min as varchar(10)) Field , This is because we declare that @min A variable is int Type of , And then there's “ For annual data ” And what we are looking for Remark The fields are vachar Type of , So we need to int Type to varchar, Otherwise, the following mistakes will occur ：

in addition , If you type it from the command line , Pay attention to copy and paste SQL Line breaks in statements .

Execute as shown in the figure for loop ：

Finally, test the data , adopt , Oh yeah \(^o^)/！！

for Introduction to loop syntax ：

  --                                  ╔════════╗  

  -- ===============================  ║ if Examples of statement usage ║  

  --                                  ╚════════╝   

            declare @a int  

            set @a=12  

            if @a>100  

               begin  

                   print @a  

               end  

            else  

               begin  

                   print 'no'  

               end  

  --                                  ╔══════════╗  

  -- ===============================  ║ while Examples of statement usage  ║  

  --                                  ╚══════════╝

declare @i int 

set @i=1 

while @i<30 

   begin 

   insert into test (userid) values(@i) 

   set @[email protected]+1 

end

 

-- Set repeat execution SQL The condition of a statement or statement block . As long as the specified condition is true , Just repeat the statement . have access to BREAK and CONTINUE Keywords are controlled inside the loop WHILE The execution of a statement in a loop . This article was obtained from the Internet before ！

 

 

  --                                   ╔════════╗  

  -- ================================  ║   Temporary tables and try   ║  

  --                                   ╚════════╝   

   

      -- Add temporary table  

       select * into #csj_temp from csj  

          

       -- Delete temporary table be used try  

        begin try    -- Detection code starts  

             drop table #csj_temp  

        end try  

   

        begin catch  -- The mistake started  

        end catch 

 

 

 --                                  ╔═════════╗  

 -- ===============================  ║ The cursor loops through the record   ║  

 --                                  ╚═════════╝   

            

            declare @temp_temp int  

            --declare @Cur_Name  

            [email protected]_Name="aaa"  

            --------------------------------- Create cursors  --Local( Local Cursor )  

            DECLARE aaa CURSOR for select House_Id from House_House where Deleted=0 or deleted is null  

            ----------------------------------- Open cursor  

              Open aaa  

            ----------------------------------- Traversing and getting cursors  

                 

            fetch next from aaa into @temp_temp  

            --print @temp_temp  

            while @@fetch_status=0  

            begin  

              -- Do what you want to do    

              select * from House_monthEnd where [email protected]_temp  

   

              fetch next from aaa into @temp_temp  -- Values are assigned to variables  

   

             --   

            end  

   

            ----------------------------------- Close cursor  

              Close aaa  

            ----------------------------------- Delete cursor  

              Deallocate aaa  

            --      

 

 

 

 

 

 

 

 

 

 

 

Reference article ：

for The realization of the cycle ：

https://zhidao.baidu.com/question/72824226.html

https://zhidao.baidu.com/question/82332450.html

https://www.cnblogs.com/xielong/p/5941595.html

SqlServer Type splicing problem ：

https://zhidao.baidu.com/question/2073884979869176588.html

Finally, I feel ：

It is also used in recent projects SqlServer Knowledge , I thought that the database teacher talked about this in college , I got the exam for Circulation? , Ha ha ha , But now it's all forgotten , Turn over the previous courseware , You can still pick up the information , Thanks to all the teachers in the University ！