object IPreparable.Prepare(IExpressionPreparer preparer)
{
var column = new SqlTableColumn(ColumnName, ColumnType);
if (DefaultExpression != null)
column.DefaultExpression = DefaultExpression.Prepare(preparer);
column.IsNotNull = IsNotNull;
column.IsIdentity = IsIdentity;
column.IndexType = IndexType;
return column;
}