connection=sqlite3.connect(':memory:')
cursor=connection.cursor()
cursor.execute('CREATE TABLE foo (bar INTEGER UNIQUE,baz INTEGER)')

这里我们插入一次行：

cursor.execute('INSERT INTO foo (bar,baz) VALUES (?,?)',(1,2))

尝试再次插入行失败：

try:
    cursor.execute('INSERT INTO foo (bar,2))
except sqlite3.IntegrityError as err:
    print(err)
    # sqlite3.IntegrityError: column bar is not unique

INSERT或IGNORE仅在传递UNIQUE约束时才插入记录：

cursor.execute('INSERT OR IGNORE INTO foo (bar,3))

cursor.execute('SELECT * from foo')
data=cursor.fetchall()
print(data)
# [(1,2)]

要在多个字段上创建UNIQUE索引,请使用类似的内容

cursor.execute('''
    CREATE TABLE foo (bar INTEGER,baz INTEGER,bing INTEGER,UNIQUE (bar,baz))''')

以下是信息的链接

> INSERT OR IGNORE
> UNIQUE constraints