Temporary Tables And Table Variables In SQL 基本常识 1. 局部临时表(#开头)只对当前连接有效,当前连接断开时自动删除 2. 全局临时表(##开头)对其它连接也有效,在当前连接和其他访问过它的连接都断开时自动删除 3. 临时表就像普通表一样,它可以做索引等等 4. 临时表存在 tempdb database, 表变量存在 memory...
Step 1. To create a table variable, the appropriate syntax involves using the DECLARE statement in conjunction with the TABLE. Syntax for Declaring a Table Variable. DECLARE @TableName TABLE ( Column1 DataType PRIMARY KEY, -- Primary key example Column2 DataType, Column3 DataType );...
Temporary Table vs Table Variable There are two ways to create a temporary table: 1. ‘On the fly’ by designating an “INTO” clause after a SELECT statement and before a FROM clause: 2. The same way as defining an actual table by using the following syntax: ...
我们不能使用语句创建表变量 select * into @tableVariableName 但是我们可以使用Create table语句和语句创建临时表 select * into #tempTableName 在SQL Server 2008之后我们可以将表变量作为参数传递给存储过程。 但是我们不能把临时表作为参数传递给存储过程。 我们可以在 UDF(用户定义函数)内使用表变量,但不能...
7. Table variables are the only way you can use DML statements (INSERT, UPDATE, DELETE) on temporary data within a user-defined function. You can create a table variable within a UDF, and modify the data using one of the above statements. This is not possible with temp tables. ...
The variable will not exist after the procedure exits. There will be no table to clean up with a DROP statement. We cannot create a non-clustered index on a table variable, unless the index is a side effect of a PRIMARY KEY or UNIQUE constraint on the table. It can only have indexes...
SQL Server Temporary Table & Table Variable (临时表和表变量),参考:在数据库中临时表什么时候会被清除呢TemporaryTablesAndTableVariablesInSQL基本常识1.局部临时表(#开头)只对当前连接有效,当前连接断开时自动删除2.全局临时表(##开头)对其它连接也有效,在当前
A summarization of table variable vs. temp table is attached in the appendix. Instead of repeating those well known facts, I'll focus on several differences that are hardly mentioned so far between table variable and temp table definitions. ...
Checking Locks on Table Variables[/caption] The DML operations (i.e. Insert, Delete, Update) done on table variable are not logged. Here is the example I tried [caption id="attachment_3875" align="aligncenter" width="725"] Table Variables and Logging[/caption] ...
and we wouldn’t use it if it contained a lot of rows. But if we were only looking at a few products this could really well. Once the table variable is populated you can then join this as a table to yet another table and gather whatever information you need. So there is a lot of...