CODEWITHSUNDEEP
winformsvisual-studio-2008datagridviewsql-server-2008-r2
Tim Bostwick
Tim Bostwick

Reputation: 332

Failed to convert parameter value -- Updating changes to a DataGridView

I'm trying to update a SQL Server database when the user modifies a cell in a DataGridView on a Windows Form. I get the error 

Failed to convert parameter value from a DataGridViewTextBoxCell to a String

on the line 'update.ExecuteNonQuery()'. I'm running Visual Studio C# Express 2008 and SQL Server Management Studio Express 2008 R2. Any assistance would be greatly appreciated. 

    private void buttonUpdate_Click(object sender, EventArgs e)
    {
        // Create the UpdateCommand.
        SqlCommand update = new SqlCommand(
            "UPDATE clients SET " +
            "client_name_first = @client_name_first " +
            "WHERE client_id = @modifiedRowNum;", connect);

        // Add the parameters for the UpdateCommand.
        update.Parameters.Add(
            "@client_name_first", SqlDbType.VarChar, 50).Value = 
            dgvClients.Rows[dgvClients.CurrentCell.RowIndex + 1].Cells[dgvClients.CurrentCell.ColumnIndex];            
        update.Parameters.Add(
            "@modifiedRowNum", SqlDbType.Int, 5).Value = dgvClients.CurrentCell.RowIndex + 1;            

        // Execute the operation.
        update.ExecuteNonQuery();
    }

Upvotes: 0

Views: 193

Answers (1)

Shell
Shell

Reputation: 6849

The error is occurred because you have not specified .Value property after Cell. You are trying to assign DataGridViewCell instead of value of that cell. The value can be retrieved from cell by using .Value property.

ie. var value = dgv.Rows[RowIndex].Cell[ColumnIndex].Value.

and in the code you just need to add .Value after ..Cells[dgvClients.CurrentCell.ColumnIndex]

update.Parameters.Add("@client_name_first", SqlDbType.VarChar, 50).Value = dgvClients.Rows[dgvClients.CurrentCell.RowIndex + 1].Cells[dgvClients.CurrentCell.ColumnIndex].Value;

the complete code will be look like this

// Create the UpdateCommand.
SqlCommand update = new SqlCommand(
        "UPDATE clients SET " +
        "client_name_first = @client_name_first " +
        "WHERE client_id = @modifiedRowNum;", connect);

// Add the parameters for the UpdateCommand.
update.Parameters.Add(
        "@client_name_first", SqlDbType.VarChar, 50).Value = 
        dgvClients.Rows[dgvClients.CurrentCell.RowIndex + 1].Cells[dgvClients.CurrentCell.ColumnIndex].Value;            
update.Parameters.Add(
        "@modifiedRowNum", SqlDbType.Int, 5).Value = dgvClients.CurrentCell.RowIndex + 1;            

// Execute the operation.
update.ExecuteNonQuery();

Upvotes: 1

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