[英]Get Value From ms-access and addition all values Vb.Net
我有我的數據庫ms-access包含“客戶端”表,該表包含:(ClientName,ClientPhone,ClientAddress,ClientCredit,ClientDes)__確定! 我想在我的軟件vb.net中添加ClientCredit的所有值。 我使用此代碼及其工作,但我給我一個錯誤的值!
Dim credit As Double = 0
Try
Dim dt As DataTable = New DBConnect().selectdata( _
"SELECT ClientName, ClientPhone, ClientAddress, ClientCredit, ClientDes FROM Client;")
For i As Integer = 0 To dt.Rows.Count - 1
credit = dt.Rows(0)(3).ToString + credit
Next
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
FlatTextBox1.Text = credit
這段代碼給我結果:400,但實際結果是415.2
您不要在循環中使用索引i。 修改代碼為行(i)而不是行(0)
For i As Integer = 0 To dt.Rows.Count - 1
//credit = dt.Rows(0)(3).ToString + credit
// credit is double, why ToString
credit = Convert.ToDuble(dt.Rows(i)(3)) + credit
Next
其他解決方案:
您可以避免循環(將..next刪除),並使用DataTable的Compute方法:
credit = dt.Compute("Sum(ClientCredit)", "");
您的總和行:
credit = dt.Rows(0)(3).ToString + credit
應該讀
credit += TryCast(dt.Rows(i)(3), Double)
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