update primary key sql

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

* From sysindexkeys-- Each index and table in the database occupies one row in the table.-- Sysindexkeys. ID table ID-- Sysindexkeys. indid index ID type-- Sysindexkeys. colid column ID The primary key must be a unique index. The unique index is not necessarily a primary key. A

SQL PRIMARY KEY Instance Tutorial Database PRIMARY KEY constraintThe PRIMARY KEY constraint uniquely identifies each record in a database table.The

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

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

Subject: How to write an SQL statement that modifies the field type to "ID" and sets this field as the primary key ?? Author: China_skag () Level 1: Reputation value: 100 Forum: MS-

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:Add the settings for the database multi-field composite primary key.First, a table cannot have more than one primary key. But there are multiple fields that can be combined into one primary key, which is why sometimes the table has multiple fields with a

SELECT primary key Column Id=b.rkey, primary key Column name = (SELECT name from syscolumns WHERE Colid=b.rkey and Id=b.rkeyid), FOREIGN key table Id=b.fkeyid, foreign key table name =object_name (B.fkeyid), Foreign

Label:How to obtain primary foreign key relationships in SQL Server 2008:Transferred from: http://www.cnblogs.com/ke10/archive/2012/06/11/2544655.htmlSELECT object_name (con.constid) ' Relationship name ',object_name (Sf.fkeyid) ' primary key table ',Fcol.name '

that does not have duplicate values and does not update operations at all. Also, in a SQL Server database, a clustered index can have only one table. Therefore, the clustering index is very important and needs to be left to more important fields to use. Therefore, the index is created here in a nonclustered way, in contrast to the above table and the importance of the clustering index. Specific applicatio

SQL: insert all other columns of rows with the same primary key updated. In SQL writing, we often encounter such problems. During each insert operation, you must determine whether the data table already exists. For the same data, all the columns except the primary

-null Delete A Field Alter table mytable DROP field name; Add unique key Alter table 'test2' add unique ('userid ') Modify primary key Alter table 'test2' drop primary key, add primary key