如何避免重复文本框以便将数据插入数据库 [英] How to avoid duplicates of text box in order to inserting the data into the database

问题描述

我没有得到数据库中可用于比较给定文本框数据的任何名称，所以请告诉我如何从数据库中获取数据以便比较i / p数据以避免重复



我的尝试：



vb.net代码

< ;的WebMethod（）> _ $ / $
Public Shared Sub AddRecord（FName As String）



Dim con As New SqlConnection（Data Source =; Database =; User Id =;密码=）

尝试

Dim dt As New DataTable

Dim cmd2 As New SqlCommand（INSERT MDT_MOBILE_FEATURES_SETTINGS（FEATURES_NAME）VALUES（ @Name））

cmd2.Parameters.AddWithValue（@ Name，FName）

Dim cmd As New SqlCommand（从MDT_MOBILE_FEATURES_SETTINGS中选择FEATURES_NAME）



cmd.Connection = con



Dim da As New SqlDataAdapter（cmd）

da.Fill（dt）

Dim strFName（dt.Rows.Count - 1）As String

Dim X As String



将整数调整为整数

Dim i作为整数

strFName（i）=

对于i = 0到dt.Rows .Count - 1



如果（strFName（i）= X）那么



结束如果



下一页





strFName（a）=（a）

a = a + 1






cmd2.Connection = con

con.Open（）



cmd2.ExecuteNonQuery（）



Catch ex As Exception

Throw







结束尝试

结束Sub

i did not get any name which is available in database for comparing the given textbox data,so please tell me how to get data from database in order to comparing the i/p data for avoiding duplicates

What I have tried:

vb.net code
<WebMethod()> _
Public Shared Sub AddRecord(FName As String)

Dim con As New SqlConnection("Data Source=;Database=;User Id=;Password=")
Try
Dim dt As New DataTable
Dim cmd2 As New SqlCommand("INSERT MDT_MOBILE_FEATURES_SETTINGS(FEATURES_NAME) VALUES(@Name)")
cmd2.Parameters.AddWithValue("@Name", FName)
Dim cmd As New SqlCommand("select FEATURES_NAME from MDT_MOBILE_FEATURES_SETTINGS")

cmd.Connection = con

Dim da As New SqlDataAdapter(cmd)
da.Fill(dt)
Dim strFName(dt.Rows.Count - 1) As String
Dim X As String

Dim a As Integer
Dim i As Integer
strFName(i) =
For i = 0 To dt.Rows.Count - 1

If (strFName(i) = X) Then

End If

Next


strFName(a) = (a)
a = a + 1



cmd2.Connection = con
con.Open()

cmd2.ExecuteNonQuery()

Catch ex As Exception
Throw



End Try
End Sub

推荐答案

您好Devaraneni，



您应该在插入新行之前检查数据库中是否存在功能名称。



如果功能名称不存在则只应插入新行，否则应抛出异常并在UI中显示错误。



I希望以下代码可以帮助您。

Hi Devaraneni,

You should check if the feature name existing in the database before inserting a new row.

If the feature name does not exist then only a new row should be inserted else an exception should be thrown and an error should be displayed in the UI.

I hope following code might help you.

Public Sub AddRecord(featureName As String)
	Dim connection = New SqlConnection("Data Source=;Database=;User Id=;Password=")
	Dim sqlCmd = New SqlCommand("select Top 1 FEATURE_NAME from MDT_MOBILE_FEATURES_SETTINGS WHERE FEATURES_NAME = @featureName")

	sqlCmd.Parameters.Add(New SqlParameter("@featureName", featureName))

	sqlCmd.CommandType = CommandType.Text

	Dim result = sqlCmd.ExecuteScalar()

	If result IsNot Nothing Then
		Throw New Exception(String.Format("Feature name {0} already exist.", featureName))
	End If

	Dim sqlInsertCommand = New SqlCommand("INSERT MDT_MOBILE_FEATURES_SETTINGS(FEATURES_NAME) VALUES(@Name)")

	sqlInsertCommand.Parameters.AddWithValue("@Name", featureName)

	sqlInsertCommand.ExecuteNonQuery()

	connection.Close()
End Sub

谢谢和问候，

Chetan Ranpariya

Thanks and regards,
Chetan Ranpariya

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