To create a unique index on a table, using: SQL Server Management Studio Transact-SQLBefore You BeginBenefits of a Unique IndexMulticolumn unique indexes guarantee that each combination of values in the index key is unique. For example, if a unique index is created on a combination of LastNa...
在使用索引创建向导创建索引时,不能将计算列包含在索引中,但在直接创建或使用CREATE INDEX命令创建索引时,则可以对计算机列创建索引,这在SQL Server2000以前的版本中是不允许的,算得上是一大改进。 例8-1: 为表products 创建一个簇索引。 create unique clustered index pk_p_id on products(p_id) with pad_i...
在使用索引创建向导创建索引时,不能将计算列包含在索引中,但在直接创建或使用CREATE INDEX命令创建索引时,则可以对计算机列创建索引,这在SQL Server2000以前的版本中是不允许的,算得上是一大改进。 例8-1: 为表products 创建一个簇索引。 create unique clustered index pk_p_id on products(p_id) with pad_i...
Sql Server创建主键失败:CREATE UNIQUE INDEX 终止,因为发现对象名称 '[PPR_BasicInformation]' 和索引名称 '[PK_PPR_BasicInformation]' 有重复的键(E) 这种问题是由于主键设置了唯一性,而数据库中主键列的值又有重复的值,重复值为E,改掉其中一个值就可以了。 分类:DB_Sql Server...
A unique index can be filtered a constraint cannot. "SQL Server forces any clustered indexes to be unique ... you can still insert duplicate rows if you want, but SQL Server adds a suffix to the key internally to ensure that the row has a unique identifier" so why can't non clustered...
This topic describes how to create a unique index on a table in SQL Server 2014 by using SQL Server Management Studio or Transact-SQL. A unique index guarantees that the index key contains no duplicate values and therefore every row in the table is in some way unique. There are no ...
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SQL SERVER中用CREATE INDEX 命令创建索引 阅读更多 CREATE INDEX 既可以创建一个可改变表的物理顺序的簇索引,也可以创建提高查询性能的非簇索引。其语法如下: CREATE [UNIQUE] [CLUSTERED | NONCLUSTERED] INDEX index_name ON {table | view } column [ ASC | DESC ] [,...n])...
SQL Server、Azure SQL Database、Azure SQL 受控執行個體的語法syntaxsql 複製 CREATE [ UNIQUE ] [ CLUSTERED | NONCLUSTERED ] INDEX index_name ON ( column [ ASC | DESC ] [ ,...n ] ) [ INCLUDE ( column_name [ ,...n ] ) ] [ WHERE <filter_predicate> ] [ WITH ( <relational...
SQL Server、Azure SQL Database、Azure SQL 受控執行個體的語法syntaxsql 複製 CREATE [ UNIQUE ] [ CLUSTERED | NONCLUSTERED ] INDEX index_name ON ( column [ ASC | DESC ] [ ,...n ] ) [ INCLUDE ( column_name [ ,...n ] ) ] [ WHERE <filter_predicate> ] [ WITH ( <relational...