把所有“OleDb”开头的，都改成“SQL”，比如：OleDbCommand改成SqlCommand

con.ConnectionString = “server=你的服务器名;database=你的数据库名;uid=你的用户名;pwd=你的密码”

添加内容到数据库时我是单击“确定”按扭，运行。“确定”的代码为
search.insert("" & TextBox1.Text & "','" & TextBox2.Text & "','" &  TextBox3.Text & "','" & TextBox4.Text & "','" & TextBox5.Text  & "")
MsgBox("添加成功！", MsgBoxStyle.OKOnly, "提示")


我是依照你的方法去做了，但出现了一个问题：
“未将对象引入设置到对象的实例”


代码以黄色线条出现的是下面代码中的   ada.InsertCommand.CommandText = SQL
不知如何入手，请大师指点。谢谢

Public Shared Function insert(ByVal SQL As String) As Integer
        Dim i As Integer
        ds = New DataSet
        ada.InsertCommand.CommandText = SQL
        con.Open()
        i = ada.InsertCommand.ExecuteNonQuery()
        con.Close()
        ada.Fill(ds)
        Return (i)
    End Function
[em10][em10][em10][em10]
为了能够与sql server连接，我把整个模块代码进行了修改，就有了上面说的黄色线条的错误，修改为的模块代码为
Imports System.Data.SqlClient
Imports System.Data


Public Class search

    Public Shared con As SqlConnection
    Public Shared ada As SqlDataAdapter
    Public Shared ds As DataSet


    Public Shared Sub init()
        con = New SqlConnection
    
        '定义如何联接数据库
        Dim connStr As String
        con.ConnectionString = "Server=(local);Database=BookSystem;uid=sa;pwd=1234"
        connStr = con.ConnectionString
        '定义一个连接对象,连接到数据库
        Dim jgBookConn As New SqlConnection(connStr)
        jgBookConn.Open()
        '定义一个执行对象,用于Sql语句执行
        Dim jgBookCommand As New SqlCommand("select * from photolist")
        jgBookCommand.Connection = jgBookConn   '执行Sql语句
        '获取数据
        Dim jgReader As SqlDataReader
        jgReader = jgBookCommand.ExecuteReader(CommandBehavior.CloseConnection)

        ada = New SqlDataAdapter
        ada.SelectCommand = New SqlCommand
        ada.InsertCommand = New SqlCommand
        ada.UpdateCommand = New SqlCommand
        ada.DeleteCommand = New SqlCommand

        ada.SelectCommand.Connection = con
        ada.InsertCommand.Connection = con
        ada.UpdateCommand.Connection = con
        ada.DeleteCommand.Connection = con

    End Sub

    Public Shared Function query(ByVal SQL As String) As DataSet
        Try
            ds = New DataSet
            ada.SelectCommand.CommandText = SQL
            ada.Fill(ds)
            Return (ds)
        Catch ex As Exception
            MsgBox(ex.Message)

        End Try

    End Function

    Public Shared Function insert(ByVal SQL As String) As Integer
        Dim i As Integer
        ds = New DataSet
        ada.InsertCommand.CommandText = SQL
        con.Open()
        i = ada.InsertCommand.ExecuteNonQuery()
        con.Close()
        ada.Fill(ds)
        Return (i)
    End Function

    Public Shared Function update(ByVal SQL As String) As Integer
        Try


            Dim i As Integer
            ds = New DataSet
            ada.UpdateCommand.CommandText = SQL
            con.Open()
            i = ada.UpdateCommand.ExecuteNonQuery()
            con.Close()
            ada.Fill(ds)
            Return (i)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Function

    Public Shared Function delete(ByVal SQL As String) As Integer
        Dim i As Integer
        ds = New DataSet
        ada.DeleteCommand.CommandText = SQL
        con.Open()
        i = ada.DeleteCommand.ExecuteNonQuery()
        con.Close()
        ada.Fill(ds)
        Return (i)
    End Function
End Class