Question

我正在尝试更新DataGridView中的单元格，但是它给了我一个带有消息的异常：

参数@Description没有默认值

如果我点击进入单元格，它会给我：

索引或主键在插入查询中不能包含Null值。

AccountNumber是我的主键，但是现在整个表都是空白的，插入查询我写在dataGridView1_RowLeave事件上，而更新查询写在dataGridView1_CellValueChanged事件上插入代码：

if (dataGridView1.IsCurrentRowDirty)
{
    string connectionString = null;
    connectionString = ConfigurationManager.ConnectionStrings["AccessConnectionString"].ConnectionString;
    con.ConnectionString = connectionString;

    string cmd1 = "insert into Ledger([AccountNumber],[Account],[Date],[Description],[Post_Ref],[Debit],[Credit],[Balance])values(?,?,?,?,?,?,?,?)";
    OleDbCommand cmd = new OleDbCommand(cmd1, con);
    con.Open();
    cmd.CommandType = CommandType.Text;

    int accountNumber;

    bool accountHasValue = int.TryParse(
        dataGridView1.Rows[e.RowIndex].Cells["AccountNumber"].Value.ToString(),
        out accountNumber);

    if (accountHasValue)
    {
        cmd.Parameters.AddWithValue("@AccountNumber", accountNumber);
    }
    else
    {
        cmd.Parameters.AddWithValue("@AccountNumber", DBNull.Value);
    }

    string accounts = dataGridView1.Rows[e.RowIndex].Cells["Account"].Value.ToString();
    cmd.Parameters.AddWithValue("@Account", accounts);

    DateTime datetime;
    bool dateTimeHasValue = DateTime.TryParse(dataGridView1.Rows[e.RowIndex].Cells["Date"].Value.ToString(), out datetime);

    if (dateTimeHasValue)
    {
        cmd.Parameters.AddWithValue("@Date", datetime);
    }
    else
    {
        cmd.Parameters.AddWithValue("@Date", DBNull.Value);
    }

    string Description = dataGridView1.Rows[e.RowIndex].Cells["Description"].Value.ToString();
    cmd.Parameters.AddWithValue("@Description", Description);

    string Post_Ref = dataGridView1.Rows[e.RowIndex].Cells["Post_Ref"].Value.ToString();
    cmd.Parameters.AddWithValue("@Post_Ref", Post_Ref);

    int debit;
    bool debitHasValue = Int32.TryParse(
        dataGridView1.Rows[e.RowIndex].Cells["Debit"].Value.ToString(),
        out debit);

    if (debitHasValue)
    {
        cmd.Parameters.AddWithValue("@Debit", debit);
    }
    else
    {
        cmd.Parameters.AddWithValue("@Debit", DBNull.Value);
    }

    int Credits;
    bool CreditsHasValue = Int32.TryParse(
        dataGridView1.Rows[e.RowIndex].Cells["Credit"].Value.ToString(),
        out Credits);

    if (CreditsHasValue)
    {
        cmd.Parameters.AddWithValue("@Credit", Credits);
    }
    else
    {
        cmd.Parameters.AddWithValue("@Credit", DBNull.Value);
    }

    int Balances;
    bool BalancesHasValue = Int32.TryParse(
        dataGridView1.Rows[e.RowIndex].Cells["Balance"].Value.ToString(),
        out Balances);

    if (BalancesHasValue)
    {
        cmd.Parameters.AddWithValue("@Balance", Balances);
    }
    else
    {
        cmd.Parameters.AddWithValue("@Balance", DBNull.Value);
    }

    cmd.ExecuteNonQuery();
    dataGridView1.DataSource = null;
    dataGridView1.Refresh();

    con.Close();
}

更新代码：

private void dataGridView1_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{
    if (dataGridView1.IsCurrentRowDirty)
    {
        int accountnumber = 0;
        string Account = "";
        DateTime? Date = null;
        string Description = "";
        string Post_ref = "";
        int Debit = 0;
        int Credit = 0;
        int Balance = 0;

        if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[0].Value, DBNull.Value))
        {
            accountnumber = Convert.ToInt32(
                dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString());
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[1].Value, DBNull.Value))
        {
            Account = dataGridView1.Rows[e.RowIndex].Cells[1].Value.ToString();
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[2].Value, DBNull.Value))
        {
            Date = Convert.ToDateTime(dataGridView1.Rows[e.RowIndex].Cells[2].Value);
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[3].Value, null))
        {
            Description = dataGridView1.Rows[e.RowIndex].Cells[3].Value.ToString();
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[4].Value, null))
        {
            Post_ref = dataGridView1.Rows[e.RowIndex].Cells[4].Value.ToString();
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[5].Value, DBNull.Value))
        {
            Debit = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[5].Value.ToString());
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[6].Value, DBNull.Value))
        {
            Credit = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[6].Value.ToString());
        }
        else if (!object.ReferenceEquals(dataGridView1.CurrentRow.Cells[7].Value, DBNull.Value))
        {
            Balance = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[7].Value.ToString());
        }

        string cmd1 = ("update Ledger set [Account]=@Account,[Date]=@Date,[Description]=@Description,[Post_Ref]=@Post_ref,[Debit]=@Debit,[Credit]=@Credit,[Balance]=@Balance where [AccountNumber]=@accountnumber");
        OleDbCommand cmd = new OleDbCommand(cmd1, con);
        con.Open();
        cmd.CommandType = CommandType.Text;

        cmd.Parameters.AddWithValue("@AccountNumber", accountnumber);
        cmd.Parameters.AddWithValue("@Account", Account);
        cmd.Parameters.AddWithValue("@Date", Date);
        cmd.Parameters.AddWithValue("@Description", Description);
        cmd.Parameters.AddWithValue("@Post_Ref", Post_ref);
        cmd.Parameters.AddWithValue("@Debit", Debit);
        cmd.Parameters.AddWithValue("@Credit", Credit);
        cmd.Parameters.AddWithValue("@Balance", Balance);
        cmd.ExecuteNonQuery();
        con.Close();
        Load_data();
        dataGridView1.DataSource = null;
        dataGridView1.Refresh();
    }
}

更新datagridview单元格

0 个答案: