Unlike a PRIMARY KEY constraint, you can create multiple UNIQUE constraints for a single table and are also allowed to designate a UNIQUE constraint for columns that allow NULL values (although only one NULL value is allowed for a single column key, per table). Like primary keys, UNIQUE const...
java代码报错：java.sql.BatchUpdateException: ORA-00001: 违反唯一约束条件 (TTT.table)at oracle.jdbc.driver.DatabaseError.throwBatchUpdateException(DatabaseError.java:629)at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:9447)at oracle.jdbc.driver.OracleStatement...
'宣告PublicOverridableSubExplicitVisit ( _ nodeAsUniqueConstraint _ ) 參數 node 型別:Microsoft.Data.Schema.ScriptDom.Sql.UniqueConstraint 指定的片段型別。 .NET Framework 安全性 完全信任立即呼叫者。這個成員無法供部分信任的程式碼使用。如需詳細資訊,請參閱從部分受信任程式碼使用程式庫。
FeatureROWGUIDCOLThe option ROWGUIDCOL is not supported for columns of memory-optimized tables. Remove theROWGUIDCOLkeyword from the column definition. FeatureFOREIGN KEYApplies to:Azure SQL Database and SQL Server starting SQL Server 2016 (13.x) ...
Microsoft SQL Server 2008 R2 and Microsoft SQL Server 2012 vary as follows: Transact-SQLpartially supports this feature. Transact-SQL does not support multiple columns on both sides of an assignment. See[ISO/IEC9075-2:2011]for the definition of "column"....
允许的约束类型仅为 PRIMARY KEY、UNIQUE KEY 和 NULL。 有关语法的详细信息,请参阅 CREATE TABLE (Transact-SQL) 、CREATE FUNCTION (Transact-SQL) 和DECLARE @local_variable (Transact-SQL)。 collation_definition 由Microsoft Windows 区域设置和比较样式、Windows 区域设置和二进制表示法或 Microsoft SQL Server...
2.1.2.256 T621, Enhanced numeric functions 2.1.2.257 T641, Multiple column assignment 2.1.2.258 T652, SQL-dynamic statements in SQL routines 2.1.2.259 T654, SQL-dynamic statements in external routines 2.2 Clarifications 2.3 Error Handling 2.4 Security 3 Change Tracking 4 Index Download PDF...
2.1.2.256 T621, Enhanced numeric functions 2.1.2.257 T641, Multiple column assignment 2.1.2.258 T652, SQL-dynamic statements in SQL routines 2.1.2.259 T654, SQL-dynamic statements in external routines 2.2 Clarifications 2.3 Error Handling 2.4 Security 3 Change Tracking 4 Index Download PDF Learn...
Metadata information in SQL Server 2008 reports meaningful precision and scale values for the new date and time data types. In thesys.columnsview, theprecisionattribute describes the total number of characters in the default literal string representation of the value, and the scale describes the num...
A primary key in a relational database is a column or combination of columns that always contain unique values. Knowing the primary key value allows you to locate the row that contains it. Relational database engines, such as SQL Server, Oracle, and Microsoft Access/Jet support the creation ...