public SqlQueryable <T> Sum(Expression <Func <T, object> > expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression", "Value cannot be null");
}
this._sqlBuilder.SetSqlCommandType(SqlCommandType.Calculate);
this.Clear();
SqlProvider.Sum(expression.Body, this._sqlBuilder);
return(this);
}
protected override SqlBuilder Sum(ParameterExpression expression, SqlBuilder sqlBuilder)
{
SqlProvider.Sum(expression, sqlBuilder);
return(sqlBuilder);
}
protected override SqlBuilder Sum(UnaryExpression expression, SqlBuilder sqlBuilder)
{
SqlProvider.Sum(expression.Operand, sqlBuilder);
return(sqlBuilder);
}