求VB.NET 连接SQL数据库最简练的语句

2009-01-20 03:31:48 190 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

给STM32供电，别只接VDD和GND！VBAT、VDDA这些引脚不接会怎样？本文深入解析STM32电源设计中VBAT与VDDA引脚的关键作用，揭示仅连接VDD和GND可能导致的ADC精度下降、RTC功能异常等问题。通过实测数据对比不同连接方案，提供包括滤波电路设计、PCB布局布线和双电源自动切换在内的实用解决方案，帮助开发者优化系统稳定性与性能。阅读详情

要求：显示一个SQL表数据到DataGrid,用最少的语句实现，要从定义连接开始，语句越少得分越高(代码成功的话),控件只用一个GataGrid.

...全文

单相PWM整流器搭建训练——（一）拓扑原理介绍单相整流器是一种将交流电转换为直流电的设备，主要由变压器、整流元件和滤波电路组成。变压器将输入的交流电压转换为适合整流的较低电压，整流元件（如二极管）利用其单向导电性将交流电转换为脉动直流电，最后滤波电路去除脉动直流电中的纹波，输出较为平滑的直流电，从而实现交流到直流的转换，广泛应用于各类电源设备中。阅读详情

蔡健常熟

VB 16,718 成员 110,520 内容

+ 关注 + 加入社区

切换为时间正序

雾里看花 2009-01-21

打赏
举报

Dim DbConnAs New SqlConnection
Dim DbDataAdapter As New SqlDataAdapter
Dim DbDataSet As New DataTable
DbConn.ConnectionString = "data source=127.0.0.1;database=数据库名;uid=sa;pwd=;"
DbDataAdapter = New System.Data.OleDb.OleDbDataAdapter(strSQL, DbConn)
DbDataSet = New System.Data.DataSet
DbDataAdapter.Fill(DbDataSet, "OpenTable")
DataGridView1.DataSource = DbDataSet.Tables("OpenTable")

blues_zhao_yang 2009-01-21

打赏
举报



        Dim SqlConn As New SqlConnection

        Dim SqlDa As New SqlDataAdapter

        Dim Dt As New DataTable

        SqlConn.ConnectionString = "data source=127.0.0.1;database=数据库名;uid=sa;pwd=;"

        SqlDa.SelectCommand = New SqlCommand

        SqlDa.SelectCommand.Connection = SqlConn

        SqlDa.SelectCommand.CommandText = "select * from [表]"

        SqlConn.Open()

        SqlDa.Fill(Dt)

        SqlConn.Close()

         DataGrid1.DataSource = Dt

lovehongyun 2009-01-21

打赏
举报

Public Function SelectRows( _

    ByVal dataSet As DataSet, ByVal connectionString As String, _

    ByVal queryString As String) As DataSet



    Using connection As New SqlConnection(connectionString)

        Dim adapter As New SqlDataAdapter()

        adapter.SelectCommand = New SqlCommand( _

            queryString, connection)

        adapter.Fill(dataSet)

        Return dataSet

    End Using

End Function



DataGrid1.DataSource = SelectRows(0).DefaultView

liujiayu10 2009-01-21

打赏
举报

因为VS2005和VS2003中的表格控件不同，所以，在2005中就是上面那样，在2003中就应该是

DataGrid1.DataSource = myDs.Tables(0).DefaultView

liujiayu10 2009-01-21

打赏
举报

Dim Conn As New SqlConnection("Data Source=(local);Initial Catalog=northwind;User ID=sa;Password=1234")
Dim myDa As New SqlDataAdapter("Select * from Customers", Conn)
Dim myDs As New DataSet
myDa.Fill(myDs, "tmp")
myDa.Dispose()

DataGridView1.DataSource = myDs.Tables(0).DefaultView

hzybc 2009-01-21

打赏
举报

Dim CN As New SqlConnection
Dim CnStr As String
CnStr = "Server=192.168.1.100;DataBase=DhFyGL;Uid=DhFy;Pwd=123456"
CN.ConnectionString = CnStr
CN.Open()

Dim Sql1 As String
Sql1 = " Select Col1,Col2,Col3 from dhfyb where " & CxTj & ""
Dim Cmd As SqlCommand
Dim Ds As New DataSet
Dim DA As New SqlDataAdapter

Cmd = CN.CreateCommand
Cmd.CommandText = Sql1
If Ds.Tables.Contains("CX_TJ") = True Then Ds.Tables.Remove("CX_TJ")
DA.SelectCommand = Cmd
DA.Fill(Ds, "CX_TJ")
DataGridView3.DataSource = Nothing
DataGridView3.DataSource = Ds.Tables("CX_TJ")

lingdu1225 2009-01-20

打赏
举报

essenza 2009-01-20

打赏
举报

Public Function FillDataGridview(ByVal ObjString As Object, ByVal SqlString As String)
Using conn As New OleDb.OleDbConnection(SQL2005_String)
Try
conn.Open()
Dim MyDataSet As DataSet = New DataSet()
Dim MyOleDataAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter()
MyOleDataAdapter.SelectCommand = New OleDb.OleDbCommand(SqlString, conn)
MyOleDataAdapter.Fill(MyDataSet)
ObjString.DataSource = MyDataSet.Tables(0)

MyOleDataAdapter.Dispose()
MyDataSet.Dispose()
Catch ex As Exception ' catches any error
MessageBox.Show(ex.Message.ToString())
Finally
conn.Dispose()
End Try
End Using
Return 0
End Function



Public Function FillDataGridview(ByVal ObjString As Object, ByVal SqlString As String)

        Using conn As New OleDb.OleDbConnection(SQL2005_String)

            Try

                conn.Open()

                Dim MyDataSet As DataSet = New DataSet()

                Dim MyOleDataAdapter As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter()

                MyOleDataAdapter.SelectCommand = New OleDb.OleDbCommand(SqlString, conn)

                MyOleDataAdapter.Fill(MyDataSet)

                ObjString.DataSource = MyDataSet.Tables(0)



                MyOleDataAdapter.Dispose()

                MyDataSet.Dispose()

            Catch ex As Exception ' catches any error

                MessageBox.Show(ex.Message.ToString())

            Finally

                conn.Dispose()

            End Try

        End Using

        Return 0

    End Function

求VB.NET 连接SQL数据库最简练的语句

相关推荐