How Can I Update an OLEDB Table Using Positional Parameters Instead of Named Parameters?

Updating a Table Using OLEDB Parameters

This question focuses on updating a table with three fields: LM_code, M_Name, and Desc. While the LM_code is autogenerated, the M_Name and Desc need to be updated using OLEDB parameters.

Problem Statement

The provided code attempts to update the table using a direct SQL query, but the values are not being updated. The question suggests that using OLEDB parameters might resolve this issue.

Solution

OLEDB does not natively support named parameters. However, it recognizes the intent and allows you to pass parameters in order. To utilize this, follow these steps:

1. Use Positional Parameters: Instead of named parameters, pass the values in the order they are defined in the SQL statement.
2. Create an OLEDB Command: Establish a connection and create an OLEDB command object.
3. Add Parameters in Order: Add parameters to the command object, ensuring their order corresponds to the placeholders in the SQL query.
4. Set SQL Statement: Assign the SQL statement with positional placeholders to the command text.
5. ExecuteNonQuery: Execute the command to update the table.

Code Snippet:

using (OleDbConnection conn = new OleDbConnection(connString))
{
    conn.Open();
    OleDbCommand cmd = conn.CreateCommand();

    cmd.Parameters.Add(new OleDbParameter("@MName", M_Name));
    cmd.Parameters.Add(new OleDbParameter("@Desc", Desc));
    cmd.Parameters.Add(new OleDbParameter("@LMCode", LM_code));

    cmd.CommandText = "Update Master_Accounts SET M_Name = @MName, Desc = @Desc WHERE LM_code = @LMCode";
    cmd.ExecuteNonQuery();
}

By following this method, you can effectively update the table using OLEDB parameters, ensuring proper value propagation and field updates.

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