Be aware however that the resulting sqlar table is incomplete. It does not have a "create unique index sqlar_autoindex_1 on sqlar(name)", and you may not be able to create one because there may be duplicate name entries notwithstanding that the rows are unique.
To do this properly and include the last "name" duplicate as the unique "name" entry you would do for an arbitrary number of sqlar files: import sqlite3 cn=sqlite3.connect(sys.argv[1], isolation_level=None) # open database and turn off the broken magic cn.execute('''CREATE TABLE IF NOT EXISTS sqlar( name TEXT PRIMARY KEY, -- name of the file mode INT, -- access permissions mtime INT, -- last modification time sz INT, -- original file size data BLOB -- compressed content );''') for infile in sys.argv[2:]: cn.execute('ATTACH DATABASE ? AS d1', [infile]) cn.execute('''insert into main.sqlar select * from d1.sqlar where true on conflict (name) do update set (mode, mtime, sz, data) = (excluded.mode, excluded.mtime, excluded.sz, excluded.data);''') cn.execute('DETACH d1') cn.close() *you need to be using a version of sqlite that understands the insert on conflict (upsert) and true/false constants. where the first param is the name of the database (which may already be an sqlar database containing data) to merge into and the rest of the params are the sqlar databases to merge from. -- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> On Behalf >Of Peng Yu >Sent: Friday, 6 September, 2019 18:09 >To: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> >Subject: Re: [sqlite] Merge two sqlar files > >OK. It works. But it seems that `.ar` is not necessary. > >import sqlite3 >infile1, infile2, outfile = sys.argv[1:] >conn=sqlite3.connect(outfile) >c=conn.cursor() >c.execute('ATTACH DATABASE ? AS d1', [infile1]) >c.execute('ATTACH DATABASE ? AS d2', [infile2]) >c.execute('CREATE TABLE sqlar AS SELECT * FROM d1.sqlar UNION SELECT * >FROM d2.sqlar') >conn.commit() > >> UNION is for "unioning" the output of two select statements (with >duplicate rows removed). It does not matter if the tables are in the same >database or even on the same planet, as long as they can be accessed on the >same connection. Sqlar creates nothing more than a standard sqlite >database file with a table called sqlar that contains the data. >> >> >sqlite >> SQLite version 3.30.0 2019-09-04 07:55:38 >> Enter ".help" for usage hints. >> Connected to a transient in-memory database. >> Use ".open FILENAME" to reopen on a persistent database. >> sqlite> .ar -cf test.db appi.py >> sqlite> .ar -cf test1.db bs.py >> sqlite> attach 'test.db' as test; >> sqlite> attach 'test1.db' as test1; >> sqlite> create table sqlar as select * from test.sqlar union select * >from test1.sqlar; >> sqlite> .ar -t >> appi.py >> bs.py > >-- >Regards, >Peng >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users