Flask SQLAlchemy 数据类型和数据库的对应关系

1 数据类型

类型名MySQL类型python类型描述
SmallInteger smallint int 取值范围较小,一般为16位
Integer int int 普通整数,一般32位
BigInteger bigint int/long 不限精度的整数
Float float float 浮点数
Numeric decimal decimal.Decimal 定点数
String varchar str 变长字符串
Text tinytext str 变长字符串,64K,216−1216−1 2^{16}-1216−1=65535bytes
Text(65536) mediumtext str 变长字符串,max16M,224−1224−1 2^{24}-1224−1=16777215bytes
Text(16777216) longtext str 变长字符串,max32M,232−1232−1 2^{32}-1232−1=4294967295bytes
LargeBinary blob str 二进制文件,64K
LargeBinary(65536) mediumblob str 二进制,max16M
LargeBinary(16777216) longblob str 二进制,max32M
PickleType blob 任何python对象 自动使用Pickle序列化,只有blob
Unicode varchar unicode 变长字符串
UnicodeText text unicode 变长字符串,64K
Boolean tinyint bool 布尔值
Date date datetime.date 日期
Time time date.time 时间
DateTime datetime datetime.datetime 日期和时间
Interval datetime datetime.timedelta 时间间隔
Enum enum str 一组字符串

2 数据库类型设计

  • 建立MySQL表

class Data(db.Model):
    __tablename__ = "datas"
    id = db.Column(db.Integer, primary_key=True)
    smallInteger = db.Column(db.SmallInteger)
    bigInteger = db.Column(db.BigInteger)
    floatData = db.Column(db.Float(10))
    numericData = db.Column(db.Numeric(10))
    stringData = db.Column(db.String(250))
    textData = db.Column(db.Text(200))
    mediumText = db.Column(db.Text(65536))
    longText = db.Column(db.Text(16777216))
    largeBinary = db.Column(db.LargeBinary(300))
    mediumBlob = db.Column(db.LargeBinary(65536))
    longBlob = db.Column(db.LargeBinary(16777216))
    pickle = db.Column(db.PickleType)
    mediumPickle = db.Column(db.PickleType(65536))
    longPickle = db.Column(db.PickleType(16777216))
    unicodeData = db.Column(db.Unicode(10))
    unicodeText = db.Column(db.UnicodeText)
    booleanData = db.Column(db.Boolean(0))
    dateData = db.Column(db.Date)
    timeData = db.Column(db.Time)
    dateTime = db.Column(db.DateTime)
    interval = db.Column(db.Interval)
    enumData = db.Column(db.Enum('father', 'mother'))
    def __repr__(self):
        return "Data {}".format(self.id)

MySQL表结构

+--------------+-------------------------+------+-----+---------+----------------+
| Field        | Type                    | Null | Key | Default | Extra          |
+--------------+-------------------------+------+-----+---------+----------------+
| id           | int(11)                 | NO   | PRI | NULL    | auto_increment |
| smallInteger | smallint(6)             | YES  |     | NULL    |                |
| bigInteger   | bigint(20)              | YES  |     | NULL    |                |
| floatData     |  float                   | YES  |     | NULL    |                |
| numericData  | decimal(10,0)           | YES  |     | NULL    |                |
| stringData   | varchar(250)            | YES  |     | NULL    |                |
| textData     | tinytext                | YES  |     | NULL    |                |
| mediumText   | mediumtext              | YES  |     | NULL    |                |
| longText     | longtext                | YES  |     | NULL    |                |
| largeBinary  | blob                    | YES  |     | NULL    |                |
| mediumBlob   | mediumblob              | YES  |     | NULL    |                |
| longBlob     | longblob                | YES  |     | NULL    |                |
| pickle       | blob                    | YES  |     | NULL    |                |
| mediumPickle | blob                    | YES  |     | NULL    |                |
| longPickle   | blob                    | YES  |     | NULL    |                |
| unicodeData  | varchar(10)             | YES  |     | NULL    |                |
| unicodeText  | text                    | YES  |     | NULL    |                |
| booleanData  | tinyint(1)              | YES  |     | NULL    |                |
| dateData     | date                    | YES  |     | NULL    |                |
| timeData     | time                    | YES  |     | NULL    |                |
| dateTime     | datetime                | YES  |     | NULL    |                |
| interval     | datetime                | YES  |     | NULL    |                |
| enumData     | enum('father','mother') | YES  |     | NULL    |                |
+--------------+-------------------------+------+-----+---------+----------------+

3 Flask-MySQL键属性

属性描述生效值
primary_key 主键 True
unique 键值唯一性 True
index 索引 True
nullable 空值 True
default 默认值 null
posted on 2020-05-15 10:11  闪亮的金子  阅读(3985)  评论(1编辑  收藏  举报