如果OLE DB 提供者支援 OLE DB 2.6 結構描述資料列集 CHECK,SQL Server 查詢最佳化工具也會使用定義於遠端資料來源中基底資料表的 CHECK_CONSTRAINTS_BY_TABLE 條件約束。 結構描述資料列集 CHECK_CLAUSE 資料行應該以符合 SQL-92 規範的語法傳回 CHECK 子句述詞。 查詢最佳化工具使用條件約束資訊以消除或...
CHECK_CONSTRAINTS 適用於:SQL Server 2008 (10.0.x) 和更新版本。 指定在二進位資料流上傳作業期間,必須檢查目標資料表或檢視表的所有條件約束。 如需詳細資訊,請參閱 BULK INSERT (Transact-SQL)。 KEEPNULLS 適用於:SQL Server 2008 (10.0.x) 和更新版本。 指定在二進位資料流上傳作業期間,空白資料行應該保留...
Check constraints contain an expression the database will evaluate when you modify or insert a row. If the expression evaluates to false, the database will not save the row. Building a check constraint is similar to building a WHERE clause. You can use many of the same operators (>, <, ...
The table declaration includes column definitions and column or table constraints. The table is always put in the primary filegroup. <clr_table_type_definition> ( { column_namedata_type } [ , ...n ] ) Applies to: SQL Server 2008 (10.0.x) SP 1 and later versions, and Azure SQL Data...
139 当在兼容性级别较低的数据库上,针对特定数据类型分析兼容性级别 130 中引入的改进型精度和转换逻辑时,在 DBCC CHECKDB、DBCC CHECKTABLE 和DBCC CHECKCONSTRAINTS 等DBCC 检查命令的作用域中强制执行正确的转换语义。 有关详细信息,请参阅 SQL Server 和Azure SQL 数据库改进,以处理某些数据类型和不常见操作。
CREATE XML INDEX (Transact-SQL) DROP INDEX (Transact-SQL) Disable indexes and constraints XML indexes (SQL Server) Optimize index maintenance to improve query performance and reduce resource consumption sys.dm_db_index_physical_stats (Transact-SQL) EVENTDATA (Transact-SQL)Feed...
sys.check_constraintsfor check constraints on columns sys.key_constraintsfor key constraints (e.g. primary keys) sys.foreign_keysfor foreign key relations and alot more- check it out! You can query and join those views to get the info needed - e.g. this will list the tables, columns and...
In SQL Server, you use UNIQUE and CHECK constraints, which are database objects that enforce data integrity in SQL Server tables. To validate that a value is valid in another table, use a foreign key constraint. To validate that a value in a column is within a specific ...
For information on unique constraints in Azure Synapse Analytics, see Primary key, foreign key, and unique key in Azure Synapse Analytics. Permissions Requires ALTER permission on the table. Use SQL Server Management Studio (SSMS) Create a unique constraint using SSMS In Object Explorer, right-clic...
2 Applies to SQL Server 2012 (11.x). Nonclustered columnstore indexes: Can't have more than 1,024 columns. Can't be created as a constraint-based index. It's possible to have unique constraints, primary key constraints, and foreign key constraints on a table with a columnstore index. C...