1、正常插入的情况

connection=sqlite3.connect(':memory:')
cursor=connection.cursor()
cursor.execute('''CREATE TABLE foo (id integer primary key autoincrement ,
                                    username varchar(50),
                                    password varchar(50))''')
cursor.execute('INSERT INTO foo (username,password) VALUES (?,?)',
               ('test','test'))
print(cursor.lastrowid)

2、顺序插入两条，但是使用不同的cursor的情况

cursor.execute('INSERT INTO foo (username,password) VALUES (?,?)',
               ('blah','blah'))
cursor2=connection.cursor()
cursor2.execute('INSERT INTO foo (username,password) VALUES (?,?)',
               ('blah','blah')
print(cursor2.lastrowid)        
#输出3
print(cursor.lastrowid)
#输出2

3、插入时指定插入的Id的情况

cursor.execute('INSERT INTO foo (id,username,password) VALUES (?,?,?)',
               (100,'blah','blah'))
print(cursor.lastrowid)
#输出100

注意：一次插入多行时lastrowid返回：None

cursor.executemany('INSERT INTO foo (username,password) VALUES (?,?)',
               (('baz','bar'),('bing','bop')))
print(cursor.lastrowid)
#输出None