Query data with the same field values in a table

No data with the same field values in a table # selectp1.citynamefromforecastp1, forecastp2wherep1. citynamep2.citynameandp1. citynamep2.citameynandp1. id! P2.id;

Query data with the same field values in a table. None # query data with the same field values in a table. select p1.cityname from forecast p1, forecast p2 where p1.cityname = p2.cityname and p1.cityname = p2.cityname and p1.id! = P2.id;

Query data with the same field values in a table <无>

# Query data with the same field values in a table. select p1.cityname from forecast p1, forecast p2 where p1.cityname = p2.cityname and p1.cityname = p2.cityname and p1.id! = P2.id;