Joining two tables using pandasql

Question

I am running SQL queries in Python using Pandasql. The queries x, y and z work fine but u gives an error

x = pysql("select * from flight f left join iata i on f.ORIGIN = i.IATA;")

y = pysql("select * from flight f inner join iata i on f.ORIGIN = i.IATA;")

z = pysql("select * from flight, iata where flight.ORIGIN = iata.IATA;")

u = pysql("select * from flight f, iata i where f.ORIGIN = i.IATA;") 

The error message is

PandaSQLException: (sqlite3.OperationalError) no such table: iata [SQL: 'select * from flight f, iata i where f.ORIGIN = i.IATA;']

Question : What is wrong with u? It looks like we can use aliases in a join without mentioning left, right, inner etc. Is this true?

Answer 1

Because you must explicitly alias it with AS when using old style joins

instead

select * from flight f, iata i where f.ORIGIN = i.IATA;

write

select * from flight AS f, iata AS i where f.ORIGIN = i.IATA;

Answer 2

试试这个代码

u = pysql("SELECT * from flight f join iata i on (f.ORIGIN = i.IATA);")