这意味着使用“NOT NULL PRIMARY KEY”或“PRIMARY KEY”装饰列应该做同样的事情。但是，您正依赖SQL标准正确地依赖SQL引擎。作为一个例子，由于早期的错误，SQL Lite没有正确实现标准，并允许非整数主键中的空值（请参阅sqlite.org/lang_createtable.html）。这意味着（至少）SQLLite这两个语句做两件事。 由于“...
You can create a primary key in SQL Server (Transact-SQL) with the ALTER TABLE statement. However, you can only use the ALTER TABLE statement to create a primary key on column(s) that are already defined as NOT NULL. If the column(s) allow NULL values, you will not be able to add...
In particular the matching clause is evaluated while only holding a weak IX or IU lock.That lock sequence is compatible with another copy of the same lock sequence until the last lock, the X lock on the key you are inserting which in incompatible. That will allow two...
“The CREATE UNIQUE INDEX statement terminated because a duplicate key was found for the object name ‘dbo.Person’ and the index name ‘PK_Person’. The duplicate key value is (1).”Filed under TSQL Related Posts: Add Primary Key Create Index Syntax Add Constraint Add Column Constraint ...
@@FETCH_STATUS in nested loops @@ServerName returns wrong value in SQL SERVER 2008 ##TempTable and INSERT-SELECT FROM an existing Table with an IDENTITY column %rowtype equivalent in SQL server ++ operator in TSQL - bug or feature? 2 tables referencing each other using foreign key.is it ...
IdentityValueKeyOption IfStatement IgnoreDupKeyIndexOption IIfCall ImportanceParameterType IndexDefinition IndexExpressionOption IndexOption IndexOptionKind IndexStatement IndexStateOption IndexTableHint IndexType IndexTypeKind InlineDerivedTable InlineFunctionOption InlineResultSetDefinition InPredicate InsertBul...
Does anyone know of a good way to Drop and Recreate all Primary and Foreign Key Constraints for all tables in a database please? Ive looked at various solutions but they dont seem to capture and recreate all the PK and FK constraints for all tables Ken McKelvey SSCoach...
There are three methods that we can get use of them in order to delete dublicates in a table. One method is using the SET ROWCOUNT t-sql command. And the second method uses the TOP tsql command. But if you open the SQL Server 2005 Books Online (BOL) you will see a note indicating...
Update Allkeys set @Lastkey = Key =Key + @amountwhere TableName=@TName if @@Error <> 0 Return 0 else Return Isnull(@Lastkey,0) end and this is very much like your identity. You can even get fancy and create ranges, rollover intervals, etc but this is basically the functionality you...
2) If not how do I generate one in TSQL? 3) If so, what do I use to store my Foreign Keys. 4) How do I declare my Foreign key constraints? View 12 RepliesView Related Transact SQL :: Identify Primary And Foreign Keys In Two Table ...