KeyFields Property (MySqlCommandBuilder)

In This Topic

Gets or sets string containing list of key field names separated by semicolon. They are used to generate update commands.

Syntax

Visual Basic
C#


'Declaration Public Shadows Property KeyFields As String


public new string KeyFields {get; set;}

Property Value

The string containing list of key field names separated by semicolon.

Remarks

This property is used when the ConflictOption property is set to OverwriteChanges, otherwise all columns will be used in the WHERE clause.

If KeyFields is nonempty, its value is used as the list of columns for the WHERE clause. If KeyFields is empty, the primary key columns are used.

Example

The following example demonstrates how UPDATE and DELETE statements are generated.

csharp


public void UseKeyFields(string connectionString) { MySqlConnection conn = new MySqlConnection(connectionString); conn.Open(); MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM Test.Dept", conn); MySqlCommandBuilder commBuilder = new MySqlCommandBuilder(adapter); commBuilder.ConflictOption = ConflictOption.OverwriteChanges; commBuilder.KeyFields = "DeptNo, DName"; string updateComm = commBuilder.GetUpdateCommand().CommandText; string deleteComm = commBuilder.GetDeleteCommand().CommandText; Console.WriteLine(updateComm); Console.WriteLine(deleteComm); conn.Close(); }

public void UseKeyFields(string connectionString) {

        MySqlConnection conn = new MySqlConnection(connectionString);
        conn.Open();

        MySqlDataAdapter adapter = new MySqlDataAdapter("SELECT * FROM Test.Dept", conn);
        MySqlCommandBuilder commBuilder = new MySqlCommandBuilder(adapter);

        commBuilder.ConflictOption = ConflictOption.OverwriteChanges;

        commBuilder.KeyFields = "DeptNo, DName";

        string updateComm = commBuilder.GetUpdateCommand().CommandText;
        string deleteComm = commBuilder.GetDeleteCommand().CommandText;

        Console.WriteLine(updateComm);
        Console.WriteLine(deleteComm);
        conn.Close();
}

Visual Basic


Public Sub UseKeyFields(ByVal connectionString As String) Dim conn As MySqlConnection = New MySqlConnection(connectionString) conn.Open() Dim adapter As MySqlDataAdapter = New MySqlDataAdapter("SELECT * FROM Test.Dept", conn) Dim commBuilder As MySqlCommandBuilder = New MySqlCommandBuilder(adapter) commBuilder.ConflictOption = ConflictOption.OverwriteChanges commBuilder.KeyFields = "DeptNo, DName" Dim updateComm As String = commBuilder.GetUpdateCommand().CommandText Dim deleteComm As String = commBuilder.GetDeleteCommand().CommandText Console.WriteLine(updateComm) Console.WriteLine(deleteComm) conn.Close() End Sub

Public Sub UseKeyFields(ByVal connectionString As String)
        Dim conn As MySqlConnection = New MySqlConnection(connectionString)
        conn.Open()

        Dim adapter As MySqlDataAdapter = New MySqlDataAdapter("SELECT * FROM Test.Dept", conn)
        Dim commBuilder As MySqlCommandBuilder = New MySqlCommandBuilder(adapter)

        commBuilder.ConflictOption = ConflictOption.OverwriteChanges

        commBuilder.KeyFields = "DeptNo, DName"

        Dim updateComm As String = commBuilder.GetUpdateCommand().CommandText
        Dim deleteComm As String = commBuilder.GetDeleteCommand().CommandText

        Console.WriteLine(updateComm)
        Console.WriteLine(deleteComm)
        conn.Close()
End Sub

Reference

MySqlCommandBuilder Class
MySqlCommandBuilder Members

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