db类vb点虐 源码 vbnet ado

求vb点虐 的源代码，最好说明其解决问题，越多越好，满意加50分。

下面这段代码，是我用来计算每个月存500元进银行，连续30年，最后连本带利能有多少钱。这里面涉及复利计算。界面中右边的文本框用来输出每一次计算的结果。

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Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

  Dim nianxian As Integer '年限变量

  Dim dingcun As Integer '定存变量

  Dim fuli_big As Long '大复利

  Dim fuli_small As Long '小复利

  Dim i As Integer '循环变量

  Dim DATAstring As String '数据字符串

  nianxian = Val(年限_TextBox.Text)

  dingcun = Val(定存_TextBox.Text)

  DATAstring = ""

  For i = 1 To nianxian

      fuli_small = dingcun * (1 + 0.1875)

      dingcun = fuli_small

      fuli_big = fuli_big + fuli_small

      DATAstring = DATAstring + "[" + Trim(Str(i)) + "]" + Str(fuli_big) + Chr(13) + Chr(10)

      'DATAstring = DATAstring + "[" + Trim(Str(i)) + "]" + Str(fuli_small) + Chr(13) + Chr(10)

  Next

  'fuli_big = fuli_small

  TextBox1.Text = DATAstring

  结果_TextBox.Text = Str(fuli_big) + "元"

End Sub

VB点虐 中用SQL语句操作数据库并实时刷新显示在DataGridView中，附源码,求指导

重要的是区别两个方法：DbAdapter.Fill是读，DbCommand.ExecuteNonquery是执行修改。删除按钮下理论上应先调用修改，确认成功后，再调用读取。

利用VB.NET实现导出DataTable数据到excel中，各位大侠帮帮忙，最好有源码，谢谢，江湖救急

刚好写了个Helper类，你试验一下DataTable2Exce(这个方法代码如下：

Imports System.IO

Imports System.Data

Imports System.Data.OleDb

Public MustInherit Class ExcelHelper

Private Shared Function buildConnStr(excelFilePath As String) As String

Dim excelFileInfo As New System.IO.FileInfo(excelFilePath)

Dim constr As String

If excelFileInfo.Extension = ".xlsx" Then

constr = String.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 12.0 Xml;HDR=YES;IMEX=1'", excelFilePath)

Else

constr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'", excelFilePath)

End If

Return constr

End Function

'将datatable导入到excel

Public Shared Function DataTable2Excel(dt As DataTable, excelFilePath As String) As Boolean

If File.Exists(excelFilePath) Then

Throw New Exception("该文件已经存在！")

End If

If dt.TableName.Trim.Length = 0 Or dt.TableName.ToLower = "table" Then

dt.TableName = "Sheet1"

End If

Dim colCount As Integer = dt.Columns.Count

Dim pa(colCount - 1) As OleDb.OleDbParameter

Dim tableStructStr As String = "Create Table " dt.TableName "("

Dim connString As String = buildConnStr(excelFilePath)

Dim objconn As New OleDbConnection(connString)

Dim objcmd As New OleDbCommand

objcmd.Connection = objconn

Dim dataTypeList As New ArrayList

dataTypeList.Add("System.Decimal")

dataTypeList.Add("System.Double")

dataTypeList.Add("System.Int16")

dataTypeList.Add("System.Int32")

dataTypeList.Add("System.Int64")

dataTypeList.Add("System.Single")

Dim i As Integer = 0

For Each col As DataColumn In dt.Columns

If dataTypeList.IndexOf(col.GetType.ToString) 0 Then

pa(i) = New OleDbParameter("@" col.ColumnName, OleDbType.Double)

objcmd.Parameters.Add(pa(i))

If i + 1 = colCount Then

tableStructStr += col.ColumnName + " double)"

Else

tableStructStr += col.ColumnName + " double,"

End If

Else

pa(i) = New OleDbParameter("@" col.ColumnName, OleDbType.VarChar)

objcmd.Parameters.Add(pa(i))

If i + 1 = colCount Then

tableStructStr += col.ColumnName + " VarChar)"

Else

tableStructStr += col.ColumnName + " VarChar,"

End If

End If

i += 1

Next

Try

objcmd.CommandText = tableStructStr

If objconn.State = ConnectionState.Closed Then objconn.Open()

objcmd.ExecuteNonQuery()

Catch ex As Exception

Throw ex

End Try

Dim InsertSql_1 As String = "Insert into " + dt.TableName + " ("

Dim InsertSql_2 As String = " Values ("

Dim InsertSql As String = ""

For colID As Integer = 0 To colCount - 1 Step 1

If colID + 1 = colCount Then

InsertSql_1 += dt.Columns(colID).ColumnName ")"

InsertSql_2 += "@" + dt.Columns(colID).ColumnName + ")"

Else

InsertSql_1 += dt.Columns(colID).ColumnName + ","

InsertSql_2 += "@" + dt.Columns(colID).ColumnName + ","

End If

Next

InsertSql = InsertSql_1 + InsertSql_2

For rowID As Integer = 0 To dt.Rows.Count - 1 Step 1

For colID = 0 To dt.Columns.Count - 1

If pa(colID).DbType = DbType.Double And dt.Rows(rowID)(colID).ToString.Trim = "" Then

pa(colID).Value = 0

Else

pa(colID).Value = dt.Rows(rowID)(colID).ToString.Trim

End If

Next

Try

objcmd.CommandText = InsertSql

objcmd.ExecuteNonQuery()

Catch ex As Exception

Throw ex

End Try

Next

Try

If objconn.State = ConnectionState.Open Then objconn.Close()

Catch exp As Exception

Throw exp

End Try

Return True

End Function

' 获取Excel文件数据表列表Sheets

Public Shared Function GetExcelTables(ExcelFileName As String) As ArrayList

'Dim sheets As New List(Of String)

'conn.Open()

'Dim dt As DataTable = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, Nothing)

'For Each r In dt.Rows

' sheets.Add(r("TABLE_NAME"))

'Next

'conn.Close()

'Return sheets

Dim dt As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

Return Nothing

End If

Dim tableList As New ArrayList

Using conn As OleDbConnection = New OleDbConnection(buildConnStr(ExcelFileName))

Try

conn.Open()

dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, New Object() {Nothing, Nothing, Nothing, "TABLE"})

Catch ex As Exception

Throw ex

End Try

For i As Integer = 0 To dt.Rows.Count - 1

Dim tableName As String = dt.Rows(i)(2).ToString.Trim.TrimEnd("$")

If tableList.IndexOf(tableName) 0 Then tableList.Add(tableName)

Next

End Using

Return tableList

End Function

'将Excel文件导出至DataTable(第一行作为表头)

Public Shared Function InputFromExcel(ExcelFileName As String, TableName As String) As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

End If

Dim tableList As ArrayList = GetExcelTables(ExcelFileName)

If tableList.IndexOf(TableName) 0 Then

TableName = tableList(0).ToString.Trim

End If

Dim dt As New DataTable

Dim conn As New OleDbConnection(buildConnStr(ExcelFileName))

Dim cmd As New OleDbCommand("select * from [" TableName "$]", conn) '调试是否需要$

Dim adapter As New OleDbDataAdapter(cmd)

Try

If conn.State = ConnectionState.Closed Then conn.Open()

adapter.Fill(dt)

Catch ex As Exception

Throw ex

Finally

If conn.State = ConnectionState.Open Then conn.Close()

End Try

Return dt

End Function

'查询excel文件中的一个数据

Public Shared Function ReadOneDataFromExcel(ExcelFileName As String, TableName As String, sql As String) As Object

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

End If

Dim tableList As ArrayList = GetExcelTables(ExcelFileName)

If tableList.IndexOf(TableName) 0 Then

TableName = tableList(0).ToString.Trim

End If

Dim dt As New DataTable

Dim conn As New OleDbConnection(buildConnStr(ExcelFileName))

Dim cmd As New OleDbCommand(sql, conn) '调试是否需要$

Dim ret As Object

Try

If conn.State = ConnectionState.Closed Then conn.Open()

ret = cmd.ExecuteScalar()

Catch ex As Exception

Throw ex

Finally

If conn.State = ConnectionState.Open Then conn.Close()

End Try

Return ret

End Function

'获取Excel文件指定数据表的数据列表columnNames

Public Shared Function GetExcelTableColumns(ExcelFileName As String, TableName As String) As ArrayList

Dim dt As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

Return Nothing

End If

Dim ColList As New ArrayList

Using conn As OleDbConnection = New OleDbConnection(buildConnStr(ExcelFileName))

Try

conn.Open()

dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, New Object() {Nothing, Nothing, TableName, Nothing})

Catch ex As Exception

Throw ex

End Try

For i As Integer = 0 To dt.Rows.Count - 1

Dim ColName = dt.Rows(i)("Column_Name").ToString().Trim()

ColList.Add(ColName)

Next

End Using

Return ColList

End Function

End Class

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