單表操作

建立一張表，如下所示

1|r&d
2|sales
3|financial

# 增
models.UserGroup.objects.create(title='sales')
# 刪
models.UserGroup.objects.filter(id=3).delete()
# 改
models.UserGroup.objects.filter(id=1).update(title='r&d')
# 查
v = models.UserGroup.objects.all()
    print(v) # <QuerySet [<UserGroup: UserGroup object>, <UserGroup: UserGroup object>, <UserGroup: UserGroup object>]>
 

    print(v.first()) # UserGroup object
    print(v.first().title) # r&d
    print(v.last()) # UserGroup object
    print(v.last().title) # financial
    print(v.all()) # <QuerySet [<UserGroup: UserGroup object>, <UserGroup: UserGroup object>, <UserGroup: UserGroup object>]>
 

    print(v.values()) # <QuerySet [{'id': 1, 'title': 'r&d'}, {'id': 2, 'title': 'sales'}, {'id': 3, 'title': 'financial'}]>
    print(v.values()[0]) # {'id': 1, 'title': 'r&d'}
    print(v.values_list()) # <QuerySet [(1, 'r&d'), (2, 'sales'), (3, 'financial')]>
    print(v.values_list()[0
 
]) # (1, 'r&d')
# 另外一種查詢試音get，得到的是 一個物件， 只有查詢到的資料，如果查詢不到丟擲異常，如果匹配到多條資料丟擲異常
 v = models.UserGroup.objects.get(id=1)
    print(v) # UserGroup object
    print(v.title) # r&d

# 使用雙下滑線查詢
v = models.UserGroup.objects.filter(id__gt=1) # 表示id>1
    print(v) # <QuerySet [<UserGroup: UserGroup object>, <UserGroup: UserGroup object>]>
    for row in v:
        print(row.id, row.title)
    """
    2 sales
    3 financial
    """

關於雙下滑線的應用