什么是存储过程?

什么是“存储过程”，它们是如何工作的?

存储过程是由什么组成的(每个东西都必须是存储过程)?

当前回答

一般来说，存储过程是一个“SQL函数”。他们有:

-- a name
CREATE PROCEDURE spGetPerson
-- parameters
CREATE PROCEDURE spGetPerson(@PersonID int)
-- a body
CREATE PROCEDURE spGetPerson(@PersonID int)
AS
SELECT FirstName, LastName ....
FROM People
WHERE PersonID = @PersonID

这是一个以T-SQL为重点的示例。存储过程可以执行大多数SQL语句，返回标量值和基于表的值，并且被认为更安全，因为它们可以防止SQL注入攻击。

2009-01-19 22:45:29

其他回答

存储过程是一个预编译的SQL语句集，它执行一些特定的任务。存储过程应该使用EXEC单独执行存储过程可以返回多个参数存储过程可用于实现事务

2016-05-31 13:15:15

SQL Server中的存储过程可以接受输入参数并返回多个输出参数值;在SQL Server中，存储过程编写语句在数据库中执行操作，并将状态值返回给调用过程或批处理。

在SQL Server中使用存储过程的好处

它们允许模块化编程。它们允许更快的执行。它们可以减少网络流量。它们可以用作一种安全机制。

下面是一个存储过程的示例，它接受参数，执行查询并返回结果。具体来说，存储过程接受BusinessEntityID作为参数，并使用它来匹配HumanResources的主键。Employee表返回所请求的员工。

> create procedure HumanResources.uspFindEmployee    `*<<<---Store procedure name`*
@businessEntityID                                     `<<<----parameter`
as
begin
SET NOCOUNT ON;
Select businessEntityId,              <<<----select statement to return one employee row
NationalIdNumber,
LoginID,
JobTitle,
HireData,
From HumanResources.Employee
where businessEntityId =@businessEntityId     <<<---parameter used as criteria
end

这是我从essential.com上学到的，非常有用。

2017-09-13 07:21:45

想想这样的情况，

You have a database with data. There are a number of different applications needed to access that central database, and in the future some new applications too. If you are going to insert the inline database queries to access the central database, inside each application's code individually, then probably you have to duplicate the same query again and again inside different applications' code. In that kind of a situation, you can use stored procedures (SPs). With stored procedures, you are writing number of common queries (procedures) and store them with the central database. Now the duplication of work will never happen as before and the data access and the maintenance will be done centrally.

注意:

In the above situation, you may wonder "Why cannot we introduce a central data access server to interact with all the applications? Yes. That will be a possible alternative. But, The main advantage with SPs over that approach is, unlike your data-access-code with inline queries, SPs are pre-compiled statements, so they will execute faster. And communication costs (over networks) will be at a minimum. Opposite to that, SPs will add some more load to the database server. If that would be a concern according to the situation, a centralized data access server with inline queries will be a better choice.

2016-05-22 06:13:18

create procedure <owner>.<procedure name><param> <datatype>
As
    <body>

存储过程是将数据访问集中在一点上的SQL语句组。适用于在一个镜头中执行多个操作。

2023-01-23 02:50:04

存储过程不过是编译成单个执行计划的一组SQL语句。

创建一次，调用n次减少网络流量

示例:创建存储过程

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE GetEmployee
      @EmployeeID int = 0
AS
BEGIN
      SET NOCOUNT ON;

      SELECT FirstName, LastName, BirthDate, City, Country
      FROM Employees 
      WHERE EmployeeID = @EmployeeID
END
GO

更改或修改存储过程:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE GetEmployee
      @EmployeeID int = 0
AS
BEGIN
    SET NOCOUNT ON;

    SELECT FirstName, LastName, BirthDate, City, Country
    FROM Employees 
    WHERE EmployeeID = @EmployeeID
END
GO

删除存储过程:

DROP PROCEDURE GetEmployee

2015-12-28 15:30:07

什么是存储过程?

推荐文章

最新文章

标签