private void ResizeColumnsIfRequired(DataTable toProcess, IDataLoadEventListener listener)
{
var tbl = _database.ExpectTable(TargetTableName);
var typeTranslater = tbl.GetQuerySyntaxHelper().TypeTranslater;
//Get the current estimates from the datatype computer
Dictionary <string, string> oldTypes = _dataTypeDictionary.ToDictionary(k => k.Key, v => v.Value.GetSqlDBType(typeTranslater), StringComparer.CurrentCultureIgnoreCase);
//adjust the computer to
//work out the max sizes - expensive bit
foreach (DataRow row in toProcess.Rows)
{
//for each destination column
foreach (string col in _dataTypeDictionary.Keys)
{
//if it appears in the toProcess DataTable
if (toProcess.Columns.Contains(col))
{
//run the datatype computer over it to compute max lengths
_dataTypeDictionary[col].AdjustToCompensateForValue(row[col]);
}
}
}
//see if any have changed
foreach (DataColumn column in toProcess.Columns)
{
//get what is required for the current batch and the current type that is configured in the live table
string oldSqlType = oldTypes[column.ColumnName];
string newSqlType = _dataTypeDictionary[column.ColumnName].GetSqlDBType(typeTranslater);
bool changesMade = false;
//if the SQL data type has degraded e.g. varchar(10) to varchar(50) or datetime to varchar(20)
if (oldSqlType != newSqlType)
{
listener.OnNotify(this, new NotifyEventArgs(ProgressEventType.Warning, "Resizing column '" + column + "' from '" + oldSqlType + "' to '" + newSqlType + "'"));
var col = tbl.DiscoverColumn(column.ColumnName, _managedConnection.ManagedTransaction);
//try changing the Type to the legit type
col.DataType.AlterTypeTo(newSqlType, _managedConnection.ManagedTransaction, AlterTimeout);
changesMade = true;
}
if (changesMade)
{
_bulkcopy.InvalidateTableSchema();
}
}
}
