一对多SQLite关系查询

Question

have an sqlite database that holds many cities, each city has a month and each month has 30 days. i created this database using CoreData when i was developing iOS apps on Xcode. now i want to retrieve the days that belongs to a specific month and that month belongs to a specific city.

Database map from Xcode :

Database structure :

Any one knows how accomplish this ? thanks

Answer 1

You can use the SQLiteQueryBuilder class. You can set (and join) the tables using the setTables method.

Sets the list of tables to query. Multiple tables can be specified to perform a join. For example: setTables("foo, bar") setTables("foo LEFT OUTER JOIN bar ON (foo.id = bar.foo_id)")

Parameters inTables the list of tables to query on