... UNIQUE(column_name) ); 定义多列的unique约束 UNIQUE(column_name1,column_name2),定义约束并重命名CONSTRAINT new_name UNIQUE(column_name) 2)ALTER TABLE 时的 SQL UNIQUE 约束 ALTER TABLE table_name ADD UNIQUE (column_name) 添加多列的unique约束 UNIQUE(column_name1,column_name2),定义约束并...
server SYSNAME NULL, source_database SYSNAME NULL, source_schema SYSNAME NULL, source_table SYSNAME NULL, source_column SYSNAME NULL, is_identity_column BIT NULL, is_part_of_unique_key BIT NULL, is_updateable BIT NULL, is_computed_column BIT NULL, is_sparse_column_set BIT N...
Step 2: Create a key vault Optional - Configure an Azure Key Vault Managed HSM (Hardware Security Module) Show 6 more Applies to: SQL Server In this article, you install and configure the SQL Server Connector for Azure Key Vault. Note Microsoft Entra ID was previously known as Azure Act...
is_part_of_unique_key bit 如果數據行是唯一索引的一部分,則傳回 1(包括唯一和主要條件約束),如果不是,則傳回 0。 如果無法判斷數據行是唯一索引的一部分,則傳回NULL。 只有在要求瀏覽資訊時才會填入。 is_updateable bit 如果數據行是可更新的,則傳回 1;如果不是,則傳...
对所修改的表的主键和唯一键的key各计算一个hash值(hash字符串由更新行的index,db,table,value按照一定规则拼接,这里不深究),放入到事务的写集合中(利用主键和unique key的唯一性来检测冲突和依赖)。 记录表的外键信息,如果表是某一些表的父表,调用Rpl_transaction_write_set_ctx::set_has_related_foreign_keys...
3.SQL语言 数据准备 创建Student 表结构 CREATE DATABASE Stu USE Stu --创建学生表 CREATE DATABASE Stu USE Stu --创建学生表 CREATE TABLE Student( Sno CHAR(6) PRIMARY KEY, Sname NCHAR(20) NOT NULL, Ssex NCHAR(2) NOT NULL DEFAULT '男' CHECK (Ssex IN ('男', '女')), ...
If you useDISTINCT,UNION,GROUP BY, orHAVING, or you include an aggregate expression in theselect_list, the cursor is created asSTATIC. If each underlying table doesn't have a unique index and an ISOSCROLLcursor or if a Transact-SQLKEYSETcursor is requested, the cursor is automatically aSTATI...
ON and OFF settings also affect the CPU column in the Process Info View for Current Activity in SQL Server Management Studio. SET STATISTICS TIME ON; GO SELECT BusinessEntityID, JobTitle FROM HumanResources.Employee WHERE JobTitle LIKE 'Production%'; ...
Applies to: SQL Server (Starting with SQL Server 2012 (11.x)) Runs the action in the current database. CURRENT isn't supported for all options in all contexts. If CURRENT fails, provide the database name. <accelerated_database_recovery> ::= Applies to: SQL Server (Starting with SQL Se...
SQL Másolás SELECT i.name AS index_name , i.type_desc , i.is_unique , ds.type_desc AS filegroup_or_partition_scheme , ds.name AS filegroup_or_partition_scheme_name , i.ignore_dup_key , i.is_primary_key , i.is_unique_constraint , i.fill_factor , i.is_padded , i.is_...