Flask SQLAlchemy 數據類型和數據庫的對應關系

1 數據類型

類型名	MySQL類型	python類型	描述
SmallInteger	smallint	int	取值范圍較小，一般為16位
Integer	int	int	普通整數，一般32位
BigInteger	bigint	int/long	不限精度的整數
Float	float	float	浮點數
Numeric	decimal	decimal.Decimal	定點數
String	varchar	str	變長字符串
Text	tinytext	str	變長字符串，64K,216−1216−1 2^{16}-1216−1=65535bytes
Text(65536)	mediumtext	str	變長字符串，max16M,224−1224−1 2^{24}-1224−1=16777215bytes
Text(16777216)	longtext	str	變長字符串，max32M,232−1232−1 2^{32}-1232−1=4294967295bytes
LargeBinary	blob	str	二進制文件，64K
LargeBinary(65536)	mediumblob	str	二進制，max16M
LargeBinary(16777216)	longblob	str	二進制，max32M
PickleType	blob	任何python對象	自動使用Pickle序列化，只有blob
Unicode	varchar	unicode	變長字符串
UnicodeText	text	unicode	變長字符串，64K
Boolean	tinyint	bool	布爾值
Date	date	datetime.date	日期
Time	time	date.time	時間
DateTime	datetime	datetime.datetime	日期和時間
Interval	datetime	datetime.timedelta	時間間隔
Enum	enum	str	一組字符串

2 數據庫類型設計

• 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表結構

+--------------+-------------------------+------+-----+---------+----------------+
| 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鍵屬性

屬性	描述	生效值
primary_key	主鍵	True
unique	鍵值唯一性	True
index	索引	True
nullable	空值	True
default	默認值	null