问题:

I have 3 SQLite DBs, each having exactly the same set of 7 tables with respect to table structure. [They are Log Dumps from 3 different Machines].

I want to combine them into one SQLite DB, having those very same 7 tables, but each table should have the combined data from all the three DBs. since I want to run queries across the 3 of them. What is the best, fastest way to do it.

回答1:

Export each database do an SQL dump and then import the dumps into your new combined database.

For GUIs have a look at http://www.sqlite.org/cvstrac/wiki?p=ManagementTools

For example, with SQLiteStudio that will be Database > Export the database: Export format: SQL > Done.

回答2:

here is one way to merge two database with all tables of the same structure. I hope it could help.

import sqlite3
con3 = sqlite3.connect("combine.db")

con3.execute("ATTACH 'results_a.db' as dba")

con3.execute("BEGIN")
for row in con3.execute("SELECT * FROM dba.sqlite_master WHERE type='table'"):
    combine = "INSERT INTO "+ row[1] + " SELECT * FROM dba." + row[1]
    print(combine)
    con3.execute(combine)
con3.commit()
con3.execute("detach database dba")