/// <summary>Alter an existing table ensuring all columns exist.</summary>
/// <param name="table">The table definition to write to the database.</param>
private void AlterTable(DataTable table)
{
bool haveBegunTransaction = false;
foreach (DataColumn column in table.Columns)
{
if (!columnNamesInDb.Contains(column.ColumnName))
{
if (!haveBegunTransaction)
{
haveBegunTransaction = true;
connection.BeginTransaction();
}
// Column is missing from database file - write it.
connection.AddColumn(Name, column.ColumnName, connection.GetDBDataTypeName(column.DataType));
columnNamesInDb.Add(column.ColumnName);
}
}
// End the transaction that we started above.
if (haveBegunTransaction)
{
connection.EndTransaction();
}
}
/// <summary>Called to run the command. Can throw on error.</summary>
/// <param name="cancelToken">Is cancellation pending?</param>
public void Run(CancellationTokenSource cancelToken)
{
if (dataToWrite.Rows.Count > 0)
{
if (!tables.TryGetValue(dataToWrite.TableName, out var table))
{
table = new DatabaseTableDetails(connection, dataToWrite.TableName);
tables.Add(dataToWrite.TableName, table);
}
var query = new InsertQuery(dataToWrite);
// Make sure the table has the correct columns.
table.EnsureTableExistsAndHasRequiredColumns(dataToWrite);
// Get a list of column names.
var columnNames = dataToWrite.Columns.Cast <DataColumn>().Select(col => col.ColumnName);
try
{
connection.BeginTransaction();
// Write all rows.
foreach (DataRow row in dataToWrite.Rows)
{
query.ExecuteQuery(connection, columnNames, row.ItemArray);
}
}
finally
{
connection.EndTransaction();
query.Close(connection);
}
}
}
/// <summary>Called to run the command. Can throw on error.</summary>
/// <param name="cancelToken">Is cancellation pending?</param>
public void Run(CancellationTokenSource cancelToken)
{
if (dataToWrite.Rows.Count > 0)
{
if (!tables.TryGetValue(dataToWrite.TableName, out var table))
{
table = new DatabaseTableDetails(connection, dataToWrite.TableName);
tables.Add(dataToWrite.TableName, table);
}
var query = new InsertQuery(dataToWrite);
// Make sure the table has the correct columns.
table.EnsureTableExistsAndHasRequiredColumns(dataToWrite);
// Get a list of column names.
var columnNames = dataToWrite.Columns.Cast <DataColumn>().Select(col => col.ColumnName);
try
{
connection.BeginTransaction();
if (deleteExistingRows)
{
// fixme - this assumes that "Current" checkpoint ID is always 1.
// This should always be correct afaik, but it would be better to
// verify this at runtime.
bool tableHasCheckpointID = connection.GetColumns(dataToWrite.TableName).Any(c => c.Item1 == "CheckpointID");
connection.ExecuteNonQuery($"DELETE FROM [{dataToWrite.TableName}] {(tableHasCheckpointID ? "WHERE CheckpointID = 1" : "")}");
}
// Write all rows.
foreach (DataRow row in dataToWrite.Rows)
{
query.ExecuteQuery(connection, columnNames, row.ItemArray);
}
}
finally
{
connection.EndTransaction();
query.Close(connection);
}
}
}
