Python SQLITE3 向后插入

Question

I have a small piece of code which inserts some data into a database. However, the data is being inserting in a reverse order.
If i "commit" after the for loop has run through, it inserts backwards, if i "commit" as part of the for loop, it inserts in the correct order, however it is much slower.
How can i commit after the for loop but still retain the correct order?

import subprocess, sqlite3
output4 = subprocess.Popen(['laZagne.exe', 'all'], stdout=subprocess.PIPE).communicate()[0]
lines4 = output4.splitlines()

conn = sqlite3.connect('DBNAME')
cur = conn.cursor()


for j in lines4:
    print j
    cur.execute('insert into Passwords (PassString) VALUES (?)',(j,))
conn.commit()
conn.close()

Answer 1

You can't rely on any ordering in SQL database tables. Insertion takes place in an implementation-dependent manner, and where rows end up depends entirely on the storage implementation used and the data that is already there.

As such, no reversing takes place; if you are selecting data from the table again and these rows come back in a reverse order, then that's a coincidence and not a choice the database made.

If rows must come back in a specific order, use ORDER BY when selecting. You could order by ROWID for example, which may be increasing monotonically for new rows and thus give you an approximation for insertion order. See ROWIDs and the INTEGER PRIMARY KEY .