1. VB.net链接Mysql数据库的方法
sqlcommand = “select count( *) from user where User="+输入的User信息+"”；
如果执行这个语句返回的值大于0
说明数据库中存在此用户
2. 请问：VB.NET怎么连接SQL
Public sqlcon As System.Data.SqlClient.SqlConnection
Public sqladapter As System.Data.SqlClient.SqlDataAdapter
Public command As System.Data.SqlClient.SqlCommand
Public ds As System.Data.DataSet
Public dr As System.Data.DataTable
sqlcon = New System.Data.SqlClient.SqlConnection
sqlcon.ConnectionString = "Server=(local); Initial Catalog=test1 ; User ID="数据库sa用户"; Password="数据库密码""
ds = New System.Data.DataSet
dr = New System.Data.DataTable(" test2 ")
ds.Tables.Add(dr)
sqladapter = New System.Data.SqlClient.SqlDataAdapter("select * from test2 ", sqlcon)
sqlcon.Open()
sqladapter.Fill(dr)
sqlcon.Close()
界面上控件
DataGridView1.DataSource = dr
3. vb.net 连接sql数据库模块,如何使用
比如有个asp.net(vb.net)连接sql server 2000数据库的连接模块(mole)：
Mole MdlCommon
Public txtSQL As String '存放SQL语句
Public DBSet As DataSet '查询得到的记录集
Public ErrorMsg As String '存放错误信息
Public Function ExecuteSQL(ByVal strSQL As String, ByRef errMsg As String) As DataSet
Dim cnn As SqlClient.SqlConnection
Dim cmd As New SqlClient.SqlCommand()
Dim adpt As SqlClient.SqlDataAdapter
Dim rst As New DataSet()
Dim SplitSQL() As String
errMsg = ""
Try
SplitSQL = Split(strSQL)
cnn = New SqlClient.SqlConnection("data source=(local);initial catalog=urp;user id=sa;pwd=1234")
If InStr("INSERT,DELETE,UPDATE", UCase$(SplitSQL(0))) Then
cmd.Connection = cnn
cmd.Connection.Open()
cmd.CommandText = strSQL
cmd.ExecuteNonQuery()
Else
adpt = New SqlClient.SqlDataAdapter(strSQL, cnn)
adpt.Fill(rst)
ExecuteSQL = rst
End If
Catch ex As Exception
errMsg = ex.Message
Finally
rst = Nothing
cnn = Nothing
End Try
End Function End Mole
调用时在asp.net后台写上txtSQL="SELECT * FROM user";
DBSet=ExecuteSQL(txtSQL,ErrorMsg)就可以查询db返回结果了。