sql server update table from another table

Label:Temporary tables in SQL Server are divided into session temporary tables and permanent temporary tables. The session temp table is automatically deleted after the session ends, and the permanent temporary table is basically no different from the basic table, and it nee

After reading the article, it is very enlightening that MySQL is usually the first select when it is update, and at this point, if the index is not used, it will lock the entire table. The best use of indexesBy using the primary key, if we know the scope of the primary key (as long as it is a superset of the exact range), you can add the scope of the primary key in the query condition so that the queryBy us

Tags: details text query exec node cut how many. NET nbsp1. Select * from sys.dm_tran_locks or sp_lock view request_node field for ' X ' (exclusive lock) or ' IX ' (Intent exclusive lock)2. View process details with SP_WHO2 + PID (process ID)3. Use DBCC INPUTBUFFER (PID) to view the contents of the dead-lock statement When blocking occurs, the following command shows which process session ID is blocking which process session ID, and how many milliseconds (ms) have elapsed. As in 3, session

= object_id (N ' tempdb). #TEMP_TBL ') and type= ' U ') print ' exists ' ELSE print ' does not exist ' The following is a supplemental introduction: In SQL Server (which should be said to be in all current database products), create a resource such as a table, a view, and a stored procedure that determines whether or not the resource you are creating alr

Label:Recently made a report in which stored procedures, cursors, CTE expressions, temporal tables, and table variables are used in the report. The problem comes when the cursor iterates through the data in the CTE, stores the corresponding data in the variable, inserts the variable into the table variable, and after the cursor ends, wants to filter the table var

(SELECT [GUID] from deleted) EndgoThe basic design is complete, now test.INSERT into [dbo]. [Vdemotab] ([Guid],[username],[password],[useraccount],[amount]) SELECT NEWID (), ' User01 ', ' pw01 ', ' account01 ', 100UNION allselect NEWID (), ' User02 ', ' pw02 ', ' account02 ', 99UNION Allselect NEWID (), ' user03 ', ' pw03 ', ' account03 ', 0GOUPDATE [Vdemotab] SET [password]= ' pw ', [amount]= '] where [Amount] >=0 and [amount]the basic operation is normal! Vertical sub-

one type of variables. Table variables are also divided into local and global variables. The names of local table variables are prefixed, only the local user connection can be accessed. The names of global table variables are prefixed with "@". Generally, they are system global variables. For example, @ error indicates the error number, @ rowcount indicates the

1, Reprinted: http://database.ctocio.com.cn/tips/442/8206442.shtml In SQL Server performance tuning, there is an incomparable problem: that is, how to process temporary datasets in a code that requires a long time or frequently called code? Table variables and temporary tables are two options. I remember seeing a large number of temporary data set processing requ

Tags: complete delete sys how to use SSI current CTI ServerIn addition to the basics of table triggers, this article also uses a bit of knowledge.1. How to use SQL to get the current session user name and machine nameSelect current_user, HOST_NAME ()2. How to get the current table name in a table triggerSELECT Object_s

1, the vertical table to the horizontal table Vertical table Structure Table_a: Converted structure: SQL example for vertical table to horizontal table: SELECT Name, sum (case when Course = n ' language ' THEN Grade EL

Post 1:Temporary tables are similar to permanent tables, but temporary tables are stored in tempdb. They are automatically deleted when they are no longer used.Temporary tables can be local or global. They differ in terms of name, visibility, and availability. The name of the local temporary table starts with a single digit (#). They are only visible to the current user connection and are deleted when the user is disconnected from the

Tags: style time span stat name not sel tab DUPI'm using a statement to save the queried data to a new table 1) using the into table statement, the new table that needs to be saved does not need to be created in advance Select * to from table-Insert new Table statement in

, @ RowCount indicates the number of affected rows. For example, let's look at the statement for creating table variables: DECLARE @ News Table(News_id int not null,NewsTitle varchar (100 ),NewsContent varchar (2000 ),NewsDateTime datetime) You can select, insert, update, and delete SQL statements to compare temporary

If you have entered this post, then you must have encountered the same problem as me. Do not look at the set case of the topic when ..., I started with the first reaction is to use case when but found not to work.It's a little bit bigger than that: dynamic specifies the field to modify.In fact, little white here did not find the solution I thought [laughter cry], but at least the problem is solved.Here are the addresses of the original posts:Http://stackoverflow.com/questions/4830191/t-

prefixed, only the local user connection can be accessed. The names of global table variables are prefixed with "@". Generally, they are system global variables. For example, @ error indicates the error number, @ rowcount indicates the number of affected rows. For example, let's look at the statement for creating table variables: Declare @ news table (news_id

A Cartesian productSELECT * FROM table 1, table 2Traverse the records of two tables to displayHorizontal connection of two tables1 using foreign key relationships as a conditionSELECT * from table 1, table 2 where table 1 table 2

http://msdn.microsoft.com/zh-cn/library/dn144699.aspx IntroductionIn SQL Server, the common table-to-table inner Join,outer Join is executed by the engine based on the selected column, the data is indexed, and the selected data is selectively converted to loop Join,merge Join,hash Join one of the three physical connect

SQL server table data change trigger mail sending method, SQL send mail Today, I encountered a problem where the original production system is running properly. Now I need to monitor a data table and send an email to the Administrator when adding data. After receiving this r

:.. From B in "server.mappath (". ") "\data.mdb" "where." 24. Create a Database CREATE DATABASE Database-name 25. Note: Delete database Drop Database dbname 26. Note: Back up SQL Server ---Create Device of Backup data Use master EXEC sp_addumpdevice disk, Testback, C:\mssql7backup\MyNwind_1.dat ---start Backup BACKUP DATABASE pubs to Testback 27. Note: Create a new

onA.uid=B.uid--left connection (based on left table, connection right with connection data, not NULL) Select * fromQ_user a Left JoinUserInformation b--inner can be omitted onA.uid=B.uid--Right connection (based on the right table) Select * fromQ_user a Right JoinUserInformation b--inner can be omitted onA.uid=B.uid--self-connect (just connect yourself to a table