Copying data from one SQLite database to another

You’ll have to attach Database X with Database Y using the ATTACH command, then run the appropriate Insert Into commands for the tables you want to transfer.

INSERT INTO X.TABLE SELECT * FROM Y.TABLE;
// "INSERT or IGNORE" if you want to ignore duplicates with same unique constraint

Or, if the columns are not matched up in order:

INSERT INTO X.TABLE(fieldname1, fieldname2) SELECT fieldname1, fieldname2 FROM Y.TABLE;