Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Specifies the properties of a PRIMARY KEY, FOREIGN KEY, UNIQUE, or CHECK constraint that is part of a new column definition added to a table by using ALTER TABLE. Примітка For Microsoft Fabric, visit ALTER ...
159 PostgreSQL multi-column unique constraint and NULL values 6 Two-column foreign key constraint only when third column is NOT NULL 2 Good way to restructure a table 5 Add a primary key constraint to an existing unique column 3 Compound unique constraint with NULL values 1 ...
CONSTRAINT_COLUMN_USAGE (Transact-SQL) 發行項 2025/01/03 11 位參與者 意見反應 適用於: SQL Server Azure SQL 資料庫 Azure SQL 受控執行個體 針對目前資料庫中定義條件約束的數據行,各傳回一個數據列。 這項資訊架構檢視會傳回目前使用者具有許可權之對象的相關信息。
SQL Server 和 Azure SQL 数据库 的语法。 syntaxsql 复制 CREATE [ OR ALTER ] VIEW [ schema_name . ] view_name [ (column [ ,...n ] ) ] [ WITH <view_attribute> [ ,...n ] ] AS select_statement [ WITH CHECK OPTION ] [ ; ] <view_attribute> ::= { [ ENCRYPTION ] [ SCHEMA...
SQL Server 和 Azure SQL 数据库 的语法。 syntaxsql CREATE[ORALTER]VIEW[schema_name. ]view_name[ (column [ ,...n ] ) ] [WITH<view_attribute>[ ,...n ] ]ASselect_statement[WITHCHECKOPTION] [ ; ]<view_attribute>::={ [ENCRYPTION] [SCHEMABINDING] [VIEW_METADATA] } ...
{ CHECK | NOCHECK } ] | ADD { <column_definition> | <computed_column_definition> | | <column_set_definition> } [ ,...n ] | [ system_start_time_column_name datetime2 GENERATED ALWAYS AS ROW START [ HIDDEN ] [ NOT NULL ] [ CONSTRAINT constraint_name ] DEFAULT constant_expression ...
Pour Microsoft Fabric, consultezALTER TABLE column_constraintet sélectionnez la version du produit souhaitée. Conventions de la syntaxe Transact-SQL Syntaxe syntaxsql [CONSTRAINTconstraint_name] { [NULL|NOTNULL] {PRIMARYKEY|UNIQUE} [CLUSTERED|NONCLUSTERED] [WITHFILLFACTOR= fillfactor ] [WITH(index_...
ALTER TABLE column_constraint指定加入數據表之新數據行定義之一部分之 PRIMARY KEY、FOREIGN KEY、UNIQUE 或 CHECK 條件約束的屬性。
83 Check constraint only one of three columns is non-null 0 unique key violation occuring on a unique value combination 5 Unable to drop non-PK index because it is referenced in a foreign key constraint 19 NVARCHAR column as PRIMARY KEY or as UNIQUE column 1 Should...
To avoid conflicts, users can add a default collation setting in the T-SQL query statement: 1 2 COLLATE DATABASE_DEFAULT WHERE Column1 COLLATE DATABASE_DEFAULT = Column2 This may prompt an issue when programming for SQL Server. Users can resolve this issue by utilizing a SQL Server column...