An attribute that specifies what type of information can be stored in a column , parameter , or variable . system - supplied data types are provided by sql server 2 .在transact - sql语句中，是指解析对数据库对象的引用时，执行语句的sql server实例。
The topics in this section contain tables of the visual basic declaration and executable statements , and of important lists that apply to many statements 本节的主题包含visual basic声明和可执行语句的表格，以及适用于许多语句的重要列表的表格。
The key performance benefit of parameterized queries is that the optimizer can formulate an access path that can be reused over repeated executions of the statement 参数化查询的主要性能好处是优化器可以制定在重复执行语句时能够再使用的存取路径。
Indicates a problem in the database engine software , but the statement completes execution , and the connection to the instance of the database engine is maintained 指示数据库引擎软件中有问题，但可完成执行语句，并且可维护到数据库引擎实例的连接。
Keyword marks a statement block as a critical section by obtaining the mutual - exclusion lock for a given object , executing a statement , and then releasing the lock 关键字将语句块标记为临界区，方法是获取给定对象的互斥锁，执行语句，然后释放该锁。
Test transact - sql statements and stored procedures in the development phase of a project by single - stepping through statements to confirm that the code works as expected 在项目开发阶段，通过单步执行语句来测试transact - sql语句和存储过程，以确保代码按预期方式运行。
When set showplan xml is on , sql server returns execution information for each statement without executing it , and transact - sql statements are not executed 如果set showplan _ xml为on ，则sql server将在不执行语句的情况下返回每个语句的执行信息。 transact - sql语句不被执行。
All statements fall into one of two categories : declaration statements , which name a variable , constant , or procedure and can also specify a data type ; or 所有语句都属于以下两个类别之一： “声明语句” （该语句命名变量、常数或过程，并还可指定数据类型）或“可执行语句” （它启动操作） 。
If the statement is executed repeatedly , a completely new transact - sql string must be built for each execution , even when the only differences are in the values supplied for the parameters 如果重复执行语句，则即使只有提供的参数值不同，每次执行时也必须生成全新的transact - sql字符串。
Is responsible for measuring performance statistics for executing statements , tracks the connections used to acquire statements , and tracks the sql strings associated with prepared and callable statements 负责测量执行语句的性能统计值，跟踪用来取得语句的连接，跟踪与预备（和可调用）语句关联的sql字符串。
