python - SQLite 在使用之间不保存数据

Question

我制作了一个包含以下内容的模块：

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())

但是当我运行它时，它打印了以下内容：

[('testing',)]
[]

它应该打印：

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

怎么了？

Answer 1

您没有将更改提交到数据库中。当你丢弃连接时，事务将被回滚。这有效

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())