如何使用SQL返回Persons表中的记录数?( )
SELECT COUNT(*) FROM Persons
SELECT COUNT() FROM Persons
SELECT COLUMNS(*) FROM Persons
SELECT COLUMNS() FROM Persons
如何使用SQL返回Persons表中的记录数?( )
SELECT COUNT(*) FROM Persons
SELECT COUNT() FROM Persons
SELECT COLUMNS(*) FROM Persons
SELECT COLUMNS() FROM Persons