VB中访问存储过程的几种办法

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使用SQL存储过程有什么好处

■SQL存储过程执行起来比SQL命令文本快得多。当一个SQL语句包含在存储过程中时，服务器不必每次执行它时都要分析和编译它。

■调用存储过程，可以认为是一个三层结构。这使你的程序易于维护。如果程序需要做某些改动，你只要改动存储过程即可

■你可以在存储过程中利用Transact-SQL的强大功能。一个SQL存储过程可以包含多个SQL语句。你可以使用变量和条件。这意味着你可以用存储过程建立非常复杂的查询，以非常复杂的方式更新数据库。

■最后，这也许是最重要的，在存储过程中可以使用参数。你可以传送和返回参数。你还可以得到一个返回值（从SQL RETURN语句）。

环境:WinXP+VB6+sp6+SqlServer2000

数据库:test

表:Users

CREATE TABLE [dbo].[users] (

[id] [int] IDENTITY (1, 1) NOT NULL ,

[truename] [char] (10) COLLATE Chinese_PRC_CI_AS NULL ,

[regname] [char] (10) COLLATE Chinese_PRC_CI_AS NULL ,

[pwd] [char] (10) COLLATE Chinese_PRC_CI_AS NULL ,

[sex] [char] (10) COLLATE Chinese_PRC_CI_AS NULL ,

[email] [text] COLLATE Chinese_PRC_CI_AS NULL ,

[jifen] [decimal](18, 2) NULL

) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

ALTER TABLE [dbo].[users] WITH NOCHECK ADD

CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED

(

[id]

) ON [PRIMARY]

存储过程select_users

CREATE PROCEDURE select_users @regname char(20), @numrows int OUTPUT

Select * from users

SELECT @numrows = @@ROWCOUNT

if @numrows = 0

return 0

else return 1

存储过程insert_users

CREATE PROCEDURE insert_users @truename char(20), @regname char(20),@pwd char(20),@sex char(20),@email char(20),@jifen decimal(19,2)

insert into users(truename,regname,pwd,sex,email,jifen) values(@truename,@regname,@pwd,@sex,@email,@jifen)

在VB环境中，添加DataGrid控件，4个按钮，6个文本框

代码简单易懂。

‘引用microsoft active data object 2.X library

Option Explicit

Dim mConn As ADODB.Connection

Dim rs1 As ADODB.Recordset

Dim rs2 As ADODB.Recordset

Dim rs3 As ADODB.Recordset

Dim rs4 As ADODB.Recordset

Dim cmd As ADODB.Command

Dim param As ADODB.Parameter

'这里用第一种方法使用存储过程添加数据

Private Sub Command1_Click()

Set cmd = New ADODB.Command

Set rs1 = New ADODB.Recordset

cmd.ActiveConnection = mConn

cmd.CommandText = "insert_users"

cmd.CommandType = adCmdStoredProc

Set param = cmd.CreateParameter("truename", adChar, adParamInput, 20, Trim(txttruename.Text))

cmd.Parameters.Append param

Set param = cmd.CreateParameter("regname", adChar, adParamInput, 20, Trim(txtregname.Text))

cmd.Parameters.Append param

Set param = cmd.CreateParameter("pwd", adChar, adParamInput, 20, Trim(txtpwd.Text))

cmd.Parameters.Append param

Set param = cmd.CreateParameter("sex", adChar, adParamInput, 20, Trim(txtsex.Text))

cmd.Parameters.Append param

Set param = cmd.CreateParameter("email", adChar, adParamInput, 20, Trim(txtemail.Text))

cmd.Parameters.Append param

‘下面的类型需要注意，如果不使用adSingle,会发生一个精度无效的错误

Set param = cmd.CreateParameter("jifen", adSingle, adParamInput, 50, Val(txtjifen.Text))

cmd.Parameters.Append param

Set rs1 = cmd.Execute

Set cmd = Nothing

Set rs1 = Nothing

End Sub

'这里用第二种方法使用存储过程添加数据

Private Sub Command2_Click()

Set rs2 = New ADODB.Recordset

Set cmd = New ADODB.Command

cmd.ActiveConnection = mConn

cmd.CommandText = "insert_users"

cmd.CommandType = adCmdStoredProc

cmd.Parameters("@truename") = Trim(txttruename.Text)

cmd.Parameters("@regname") = Trim(txtregname.Text)

cmd.Parameters("@pwd") = Trim(txtpwd.Text)

cmd.Parameters("@sex") = Trim(txtsex.Text)

cmd.Parameters("@email") = Trim(txtemail.Text)

cmd.Parameters("@jifen") = Val(txtjifen.Text)

Set rs2 = cmd.Execute

Set cmd = Nothing

Set rs1 = Nothing

End Sub

'这里用第三种方法使用连接对象来插入数据

Private Sub Command4_Click()

Dim strsql As String

strsql = "insert_users '" & Trim(txttruename.Text) & "','" & Trim(txtregname.Text) & "','" & Trim(txtpwd.Text) & "','" & Trim(txtsex.Text) & "','" & Trim(txtemail.Text) & "','" & Val(txtjifen.Text) & "'"

Set rs3 = New ADODB.Recordset

Set rs3 = mConn.Execute(strsql)

Set rs3 = Nothing

End Sub

'利用存储过程显示数据

‘要处理多种参数，输入参数，输出参数以及一个直接返回值

Private Sub Command3_Click()

Set rs4 = New ADODB.Recordset

Set cmd = New ADODB.Command

cmd.ActiveConnection = mConn

cmd.CommandText = "select_users"

cmd.CommandType = adCmdStoredProc

'返回值

Set param = cmd.CreateParameter("RetVal", adInteger, adParamReturnValue, 4)

cmd.Parameters.Append param

'输入参数

Set param = cmd.CreateParameter("regname", adChar, adParamInput, 20, Trim(txtregname.Text))

cmd.Parameters.Append param

'输出参数

Set param = cmd.CreateParameter("numrows", adInteger, adParamOutput)

cmd.Parameters.Append param

Set rs4 = cmd.Execute()

If cmd.Parameters("RetVal").Value = 1 Then

MsgBox cmd.Parameters("numrows").Value

Else

MsgBox "没有记录"

End If

MsgBox rs4.RecordCount

Set DataGrid1.DataSource = rs4

DataGrid1.Refresh

End Sub

'连接数据库

Private Sub Form_Load()

Set mConn = New Connection

mConn.ConnectionString = "Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=Test;Data Source=yang"

mConn.CursorLocation = adUseClient '设置为客户端

mConn.Open

End Sub

'关闭数据连接

Private Sub Form_Unload(Cancel As Integer)

mConn.Close

Set mConn = Nothing

End Sub