sql primary key autoincrement

\ ' database name \ ', \ ' autoshrink\ ', \ ' true\ '\\\ ' Add field general functionSub AddColumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "ADD \" columnname\ "\" columntype\ "\")End Sub\\\ ' Change field general functionSub Modcolumn (Tablename,columnname,columntype)Conn.execute (\ "Alter Table \" tablename\ "alter Column \" columnname\ "\" columntype\ "\")End Sub\\\ ' Check if the table existsSql=\ "SELECT COUNT (*) as Dida from sysobjects where id = object

is to obtain a self-growing value before inserting a record operation, in the execution Insert SQL You must specify a primary key value for the record you want to insert, so you want to before "The time to get the self-increment sequence, and then use Selectkey into the input parameter map. Assuming the self-growth or IDInsertID= "Insert"Usegeneratedkeys= "true"

Use after an SQL statementSCOPE_IDENTITY ()Of course, you can also use SELECT @ IDENTITYHowever, the use of SELECT @ IDENTITY is globally up-to-date. incorrect values may be obtained.Example:Copy codeThe Code is as follows:Insert into dbo. SNS_BlogData (userName) values ('jiangyun ');SELECT SCOPE_IDENTITY ()Gets the primary key return value for the insert into op

Use after an SQL statement SCOPE_IDENTITY () Of course, you can also use SELECT @ IDENTITY However, the use of SELECT @ IDENTITY is globally up-to-date. incorrect values may be obtained. Example:Copy codeThe Code is as follows: insert into dbo. SNS_BlogData (userName) values ('jiangyun ');SELECT SCOPE_IDENTITY () Gets the primary key return value for the insert

Original: Deletes all indexes of the specified table, including primary key indexes, unique indexes, and normal indexes, for SQL Server 2005.Deletes all indexes of the specified table, including primary key indexes, unique indexes, and normal indexes, for

Many people may confuse PrimaryKey with clustered index, or think this is the same thing. This concept is very incorrect. A primary key is a constraint attached to an index. This index can be a clustered index or a non-clustered index. So on one (or a group) Field Many people may confuse Primary Key with clustered ind

Many people may confuse PrimaryKey with clustered index, or think this is the same thing. This concept is very incorrect. A primary key is a constraint attached to an index. This index can be a clustered index or a non-clustered index. So on one (or a group) Field Many people may confuse Primary Key with clustered inde

SQL Multiple primary key tables, when the inserted data is duplicated, are prompted to violate the primary KEY constraint that cannot be inserted by the error. So, how do I find duplicate values for the inserted data? Workaround: Use Group bySuppose there is a table #a , t

= male) Five. Set the CHECK constraint. Check Age int check (age between), Six. Auto-grow. Auto_increment to be used on the primary key: Create TABLE box (ID int auto_increment primary key) Seven. Foreign key foreign key -

Label:The last day of 2014, today when importing data to the database, there is a problem, is the joint primary key to go heavy.The thing is, there is a table m, I want to find a table that imports a lot of data, and I need to set the fields a (int) and B (int) union as the primary key.But when I set the primary

Label:first, Getting started with SQL statements1. SQL statements are statements that are specific to the DBMS "talk", and the SQL syntax is recognized by different DBMS.2. The string in the SQL statement is enclosed in single quotation marks.3. SQL statements are insensitiv