Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
210 views
in Technique[技术] by (71.8m points)

python - SQLite not saving data between uses

I made a module with the following contents:

import sqlite3 as sq
connection = sq.connect("test.db")
cursor = connection.cursor()
cursor.execute("DROP TABLE IF EXISTS test")
cursor.execute("CREATE TABLE test (st TEXT)")
cursor.execute("INSERT INTO test VALUES ('testing')")
cursor.execute("SELECT * FROM test")
print(cursor.fetchall())
cursor.close()
connection.close()
connection2 = sq.connect("test.db")
cursor2 = connection2.cursor()
cursor2.execute("SELECT * FROM test")
print(cursor2.fetchall())

But when I ran it, it printed the following:

[('testing',)]
[]

It should have printed:

[('testing',)]
[('testing',)]

What is wrong?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You did not commit your changes into the DB. When you discard the connection, the transaction will be rolled back. This works

import sqlite3 as sq
connection = sq.connect("test.db")
cursor = connection.cursor()
cursor.execute("DROP TABLE IF EXISTS test")
cursor.execute("CREATE TABLE test (st TEXT)")
cursor.execute("INSERT INTO test VALUES ('testing')")
connection.commit() # !!!

cursor.execute("SELECT * FROM test")
print(cursor.fetchall())
cursor.close()
connection.close()  # rolls back changes without .commit()

connection2 = sq.connect("test.db")
cursor2 = connection2.cursor()
cursor2.execute("SELECT * FROM test")
print(cursor2.fetchall())

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...