private IEnumerable <QueryExpression> GetCreateIndexExpressions()
{
foreach (var index in _entityModel.Indexes)
{
yield return(QueryExpression.CreateIndex(
_entityModel.Table.TableName,
index.HasUniqueConstraint,
index.Fields.Where(q => q.Column != null).Select(q => q.Column.Name).ToArray()
));
}
}