Dataset questions | 易学教程

问题

I have two dataset questions.

If I change any cell in a dataset, how I can update this change in a database without using an SQL update query?
How can I see dataset contents in debug mode (to see the data)?

回答1:

You can't update a database without an UPDATE query. That's how updates happen. You can use libraries that abstract this away so that you don't have to see the query in your code, but the query still has to happen.
You can see the contents of a dataset in debug mode by adding it to your watch list and clicking the little magnifying glass icon. It opens up a window that lets you look at the tables in the dataset.

回答2:

You can use LINQ to update data into the database, without using T-SQL Update query.

回答3:

What you're looking for is a DataAdapter. It will manage updating, deleting and inserting changes.

回答4:

Check this code and adapt to your needs

    ///<summary>Update Batch records in DataTable</summary>
    ///<remarks></remarks>
    public void UpdateTables(System.Data.DataTable DataTable)
    {

        if (DataTable.TableName.Length == 0)
        {
            throw new Exception("The DataTable tablename is nedded.");
        }

        if (this.State == ConnectionState.Closed)
        {
            this.Connect();
        }

        try
        {
            string strTablename = DataTable.TableName, strSQL;
            System.Data.IDbDataAdapter dt = null;

            if (DataTable.TableName.Length == 0)
            {
                throw new Exception("Tablename can't be null.");
            }

            strSQL = "SELECT * FROM " + strTablename;

            if (m_DatabaseType == DatabaseTypeEnum.Access)
            {
                dt = new System.Data.OleDb.OleDbDataAdapter(strSQL, m_ConnectionString);
                System.Data.OleDb.OleDbCommandBuilder cb_a
                    = new System.Data.OleDb.OleDbCommandBuilder((System.Data.OleDb.OleDbDataAdapter)dt);

                dt.InsertCommand = cb_a.GetInsertCommand();
                dt.UpdateCommand = cb_a.GetUpdateCommand();
                dt.DeleteCommand = cb_a.GetDeleteCommand();

                ((System.Data.OleDb.OleDbDataAdapter)dt).Update(DataTable);
            }
            else if (m_DatabaseType == DatabaseTypeEnum.SQLServer)
            {
                dt = new System.Data.SqlClient.SqlDataAdapter(strSQL, m_ConnectionString);
                System.Data.SqlClient.SqlCommandBuilder cb_s
                    = new System.Data.SqlClient.SqlCommandBuilder((System.Data.SqlClient.SqlDataAdapter)dt);

                dt.InsertCommand = cb_s.GetInsertCommand();
                dt.UpdateCommand = cb_s.GetUpdateCommand();
                dt.DeleteCommand = cb_s.GetDeleteCommand();

                ((System.Data.SqlClient.SqlDataAdapter)dt).Update(DataTable);
            }
            else if (m_DatabaseType == DatabaseTypeEnum.Oracle)
            {
                dt = new System.Data.OracleClient.OracleDataAdapter(strSQL, m_ConnectionString);
                System.Data.OracleClient.OracleCommandBuilder cb_o
                    = new System.Data.OracleClient.OracleCommandBuilder((System.Data.OracleClient.OracleDataAdapter)dt);

                dt.InsertCommand = cb_o.GetInsertCommand();
                dt.UpdateCommand = cb_o.GetUpdateCommand();
                dt.DeleteCommand = cb_o.GetDeleteCommand();

                ((System.Data.OracleClient.OracleDataAdapter)dt).Update(DataTable);
            }
            else if (m_DatabaseType == DatabaseTypeEnum.Odbc)
            {
                dt = new System.Data.Odbc.OdbcDataAdapter(strSQL, m_ConnectionString);
                System.Data.Odbc.OdbcCommandBuilder cb_c
                    = new System.Data.Odbc.OdbcCommandBuilder((System.Data.Odbc.OdbcDataAdapter)dt);

                dt.InsertCommand = cb_c.GetInsertCommand();
                dt.UpdateCommand = cb_c.GetUpdateCommand();
                dt.DeleteCommand = cb_c.GetDeleteCommand();

                ((System.Data.Odbc.OdbcDataAdapter)dt).Update(DataTable);
            }
            else
            {
                throw new NotImplementedException();
            }

            DataTable.AcceptChanges();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
    }

来源：https://stackoverflow.com/questions/982135/dataset-questions

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dataset