sequelizejs中文文檔（二）Model定義

英文文檔

Model定義

用define方法來定義模型與表之間的映射關係。

const Project = sequelize.define('project', {
  title: Sequelize.STRING,
  description: Sequelize.TEXT
})

const Task = sequelize.define('task', {
  title: Sequelize.STRING,
  description: Sequelize.TEXT,
  deadline: Sequelize.DATE
})

你還能夠在每列上設置一些選項：

const Foo = sequelize.define('foo', {
 // instantiating will automatically set the flag to true if not set
 flag: { type: Sequelize.BOOLEAN, allowNull: false, defaultValue: true },

 // default values for dates => current time
 myDate: { type: Sequelize.DATE, defaultValue: Sequelize.NOW },

 // setting allowNull to false will add NOT NULL to the column, which means an error will be
 // thrown from the DB when the query is executed if the column is null. If you want to check that a value
 // is not null before querying the DB, look at the validations section below.
 title: { type: Sequelize.STRING, allowNull: false },

 // Creating two objects with the same value will throw an error. The unique property can be either a
 // boolean, or a string. If you provide the same string for multiple columns, they will form a
 // composite unique key.
 uniqueOne: { type: Sequelize.STRING,  unique: 'compositeIndex' },
 uniqueTwo: { type: Sequelize.INTEGER, unique: 'compositeIndex' },

 // The unique property is simply a shorthand to create a unique constraint.
 someUnique: { type: Sequelize.STRING, unique: true },

 // It's exactly the same as creating the index in the model's options.
 { someUnique: { type: Sequelize.STRING } },
 { indexes: [ { unique: true, fields: [ 'someUnique' ] } ] },

 // Go on reading for further information about primary keys
 identifier: { type: Sequelize.STRING, primaryKey: true },

 // autoIncrement can be used to create auto_incrementing integer columns
 incrementMe: { type: Sequelize.INTEGER, autoIncrement: true },

 // You can specify a custom field name via the 'field' attribute:
 fieldWithUnderscores: { type: Sequelize.STRING, field: 'field_with_underscores' },

 // It is possible to create foreign keys:
 bar_id: {
   type: Sequelize.INTEGER,

   references: {
     // This is a reference to another model
     model: Bar,

     // This is the column name of the referenced model
     key: 'id',

     // This declares when to check the foreign key constraint. PostgreSQL only.
     deferrable: Sequelize.Deferrable.INITIALLY_IMMEDIATE
   }
 }
})

Timestamps

默認狀況下，Sequelize會將createdAt和updatedAt的屬性添加到模型中，以便您能夠知道數據庫條目什麼時候進入數據庫以及什麼時候被更新。

請注意，若是您使用Sequelize遷移，則須要將createdAt和updatedAt字段添加到遷移定義中：

module.exports = {
  up(queryInterface, Sequelize) {
    return queryInterface.createTable('my-table', {
      id: {
        type: Sequelize.INTEGER,
        primaryKey: true,
        autoIncrement: true,
      },

      // Timestamps
      createdAt: Sequelize.DATE,
      updatedAt: Sequelize.DATE,
    })
  },
  down(queryInterface, Sequelize) {
    return queryInterface.dropTable('my-table');
  },
}

若是您不想在模型上使用時間戳，只須要一些時間戳，或者您正在使用現有的數據庫，其中列被命名爲別的東西，請直接跳轉到配置，以瞭解如何執行此操做。

Data types

如下是sequelizejs所支持的一些數據類型。 有關完整和更新的列表，請參閱數據類型。

Sequelize.STRING                      // VARCHAR(255)
Sequelize.STRING(1234)                // VARCHAR(1234)
Sequelize.STRING.BINARY               // VARCHAR BINARY
Sequelize.TEXT                        // TEXT
Sequelize.TEXT('tiny')                // TINYTEXT

Sequelize.INTEGER                     // INTEGER
Sequelize.BIGINT                      // BIGINT
Sequelize.BIGINT(11)                  // BIGINT(11)

Sequelize.FLOAT                       // FLOAT
Sequelize.FLOAT(11)                   // FLOAT(11)
Sequelize.FLOAT(11, 12)               // FLOAT(11,12)

Sequelize.REAL                        // REAL        PostgreSQL only.
Sequelize.REAL(11)                    // REAL(11)    PostgreSQL only.
Sequelize.REAL(11, 12)                // REAL(11,12) PostgreSQL only.

Sequelize.DOUBLE                      // DOUBLE
Sequelize.DOUBLE(11)                  // DOUBLE(11)
Sequelize.DOUBLE(11, 12)              // DOUBLE(11,12)

Sequelize.DECIMAL                     // DECIMAL
Sequelize.DECIMAL(10, 2)              // DECIMAL(10,2)

Sequelize.DATE                        // DATETIME for mysql / sqlite, TIMESTAMP WITH TIME ZONE for postgres
Sequelize.DATE(6)                     // DATETIME(6) for mysql 5.6.4+. Fractional seconds support with up to 6 digits of precision
Sequelize.DATEONLY                    // DATE without time.
Sequelize.BOOLEAN                     // TINYINT(1)

Sequelize.ENUM('value 1', 'value 2')  // An ENUM with allowed values 'value 1' and 'value 2'
Sequelize.ARRAY(Sequelize.TEXT)       // Defines an array. PostgreSQL only.

Sequelize.JSON                        // JSON column. PostgreSQL only.
Sequelize.JSONB                       // JSONB column. PostgreSQL only.

Sequelize.BLOB                        // BLOB (bytea for PostgreSQL)
Sequelize.BLOB('tiny')                // TINYBLOB (bytea for PostgreSQL. Other options are medium and long)

Sequelize.UUID                        // UUID datatype for PostgreSQL and SQLite, CHAR(36) BINARY for MySQL (use defaultValue: Sequelize.UUIDV1 or Sequelize.UUIDV4 to make sequelize generate the ids automatically)

Sequelize.RANGE(Sequelize.INTEGER)    // Defines int4range range. PostgreSQL only.
Sequelize.RANGE(Sequelize.BIGINT)     // Defined int8range range. PostgreSQL only.
Sequelize.RANGE(Sequelize.DATE)       // Defines tstzrange range. PostgreSQL only.
Sequelize.RANGE(Sequelize.DATEONLY)   // Defines daterange range. PostgreSQL only.
Sequelize.RANGE(Sequelize.DECIMAL)    // Defines numrange range. PostgreSQL only.

Sequelize.ARRAY(Sequelize.RANGE(Sequelize.DATE)) // Defines array of tstzrange ranges. PostgreSQL only.

Sequelize.GEOMETRY                    // Spatial column.  PostgreSQL (with PostGIS) or MySQL only.
Sequelize.GEOMETRY('POINT')           // Spatial column with geometry type. PostgreSQL (with PostGIS) or MySQL only.
Sequelize.GEOMETRY('POINT', 4326)     // Spatial column with geometry type and SRID.  PostgreSQL (with PostGIS) or MySQL only.

BLOB數據類型容許您將數據做爲字符串和緩衝區插入。 當您在具備BLOB列的模型上執行find或findAll時，該數據將始終做爲緩衝區返回。

若是您正在使用PostgreSQL TIMESTAMP WITHOUT TIMEZONE，您須要將其解析爲不一樣的時區，請使用pg庫本身的解析器：

require('pg').types.setTypeParser(1114, stringValue => {
  return new Date(stringValue + '+0000');
  // e.g., UTC offset. Use any offset that you would like.
});

除了上述類型以外，integer，bigint，float和double也支持unsigned和zerofill屬性，能夠按任意順序組合：注意這不適用於PostgreSQL！

Sequelize.INTEGER.UNSIGNED              // INTEGER UNSIGNED
Sequelize.INTEGER(11).UNSIGNED          // INTEGER(11) UNSIGNED
Sequelize.INTEGER(11).ZEROFILL          // INTEGER(11) ZEROFILL
Sequelize.INTEGER(11).ZEROFILL.UNSIGNED // INTEGER(11) UNSIGNED ZEROFILL
Sequelize.INTEGER(11).UNSIGNED.ZEROFILL // INTEGER(11) UNSIGNED ZEROFILL

Range types

因爲範圍類型具備其綁定的包含/排除的額外信息，因此使用一個元組在javascript中表示它們並非很簡單。

將範圍提供爲值時，您能夠從如下API中進行選擇：

// defaults to '["2016-01-01 00:00:00+00:00", "2016-02-01 00:00:00+00:00")'
// inclusive lower bound, exclusive upper bound
Timeline.create({ range: [new Date(Date.UTC(2016, 0, 1)), new Date(Date.UTC(2016, 1, 1))] });

// control inclusion
const range = [new Date(Date.UTC(2016, 0, 1)), new Date(Date.UTC(2016, 1, 1))];
range.inclusive = false; // '()'
range.inclusive = [false, true]; // '(]'
range.inclusive = true; // '[]'
range.inclusive = [true, false]; // '[)'

// or as a single expression
const range = [
  { value: new Date(Date.UTC(2016, 0, 1)), inclusive: false },
  { value: new Date(Date.UTC(2016, 1, 1)), inclusive: true },
];
// '("2016-01-01 00:00:00+00:00", "2016-02-01 00:00:00+00:00"]'

// composite form
const range = [
  { value: new Date(Date.UTC(2016, 0, 1)), inclusive: false },
  new Date(Date.UTC(2016, 1, 1)),
];
// '("2016-01-01 00:00:00+00:00", "2016-02-01 00:00:00+00:00")'

Timeline.create({ range });

不過請注意，只要您收到範圍內的值，您將收到：

// stored value: ("2016-01-01 00:00:00+00:00", "2016-02-01 00:00:00+00:00"]
range // [Date, Date]
range.inclusive // [false, true]

確保在序列化以前將其轉換爲可序列化的格式，由於數組額外的屬性將不會被序列化。

Special Cases

// empty range:
Timeline.create({ range: [] }); // range = 'empty'

// Unbounded range:
Timeline.create({ range: [null, null] }); // range = '[,)'
// range = '[,"2016-01-01 00:00:00+00:00")'
Timeline.create({ range: [null, new Date(Date.UTC(2016, 0, 1))] });

// Infinite range:
// range = '[-infinity,"2016-01-01 00:00:00+00:00")'
Timeline.create({ range: [-Infinity, new Date(Date.UTC(2016, 0, 1))] });

Getters & setters

能夠在模型上定義「object-property」getter和setter函數，這些能夠用於映射到數據庫字段的「protecting」屬性，也能夠用於定義「pseudo」屬性。

Getters和Setter能夠經過兩種方式定義（您能夠混合使用這兩種方式）：

　　做爲單一屬性定義的一部分

const Employee = sequelize.define('employee', {
  name: {
    type: Sequelize.STRING,
    allowNull: false,
    get() {
      const title = this.getDataValue('title');
      // 'this' allows you to access attributes of the instance
      return this.getDataValue('name') + ' (' + title + ')';
    },
  },
  title: {
    type: Sequelize.STRING,
    allowNull: false,
    set(val) {
      this.setDataValue('title', val.toUpperCase());
    }
  }
});

Employee
  .create({ name: 'John Doe', title: 'senior engineer' })
  .then(employee => {
    console.log(employee.get('name')); // John Doe (SENIOR ENGINEER)
    console.log(employee.get('title')); // SENIOR ENGINEER
  })

　　做爲模型選項的一部分

const Foo = sequelize.define('foo', {
  firstname: Sequelize.STRING,
  lastname: Sequelize.STRING
}, {
  getterMethods: {
    fullName() {
      return this.firstname + ' ' + this.lastname
    }
  },

  setterMethods: {
    fullName(value) {
      const names = value.split(' ');

      this.setDataValue('firstname', names.slice(0, -1).join(' '));
      this.setDataValue('lastname', names.slice(-1).join(' '));
    },
  }
});

Validations

模型驗證，容許您爲模型的每一個屬性指定格式/內容/繼承驗證。

驗證將自動運行在建立，更新和保存。 您也能夠調用validate（）手動驗證一個實例。

const ValidateMe = sequelize.define('foo', {
  foo: {
    type: Sequelize.STRING,
    validate: {
      is: ["^[a-z]+$",'i'],     // will only allow letters
      is: /^[a-z]+$/i,          // same as the previous example using real RegExp
      not: ["[a-z]",'i'],       // will not allow letters
      isEmail: true,            // checks for poem format (foo@bar.com)
      isUrl: true,              // checks for url format (http://foo.com)
      isIP: true,               // checks for IPv4 (129.89.23.1) or IPv6 format
      isIPv4: true,             // checks for IPv4 (129.89.23.1)
      isIPv6: true,             // checks for IPv6 format
      isAlpha: true,            // will only allow letters
      isAlphanumeric: true,     // will only allow alphanumeric characters, so "_abc" will fail
      isNumeric: true,          // will only allow numbers
      isInt: true,              // checks for valid integers
      isFloat: true,            // checks for valid floating point numbers
      isDecimal: true,          // checks for any numbers
      isLowercase: true,        // checks for lowercase
      isUppercase: true,        // checks for uppercase
      notNull: true,            // won't allow null
      isNull: true,             // only allows null
      notEmpty: true,           // don't allow empty strings
      equals: 'specific value', // only allow a specific value
      contains: 'foo',          // force specific substrings
      notIn: [['foo', 'bar']],  // check the value is not one of these
      isIn: [['foo', 'bar']],   // check the value is one of these
      notContains: 'bar',       // don't allow specific substrings
      len: [2,10],              // only allow values with length between 2 and 10
      isUUID: 4,                // only allow uuids
      isDate: true,             // only allow date strings
      isAfter: "2011-11-05",    // only allow date strings after a specific date
      isBefore: "2011-11-05",   // only allow date strings before a specific date
      max: 23,                  // only allow values <= 23
      min: 23,                  // only allow values >= 23
      isCreditCard: true,       // check for valid credit card numbers

      // custom validations are also possible:
      isEven(value) {
        if (parseInt(value) % 2 != 0) {
          throw new Error('Only even values are allowed!')
          // we also are in the model's context here, so this.otherField
          // would get the value of otherField if it existed
        }
      }
    }
  }
});

Configuration

const Bar = sequelize.define('bar', { /* bla */ }, {
  // don't add the timestamp attributes (updatedAt, createdAt)
  timestamps: false,

  // don't delete database entries but set the newly added attribute deletedAt
  // to the current date (when deletion was done). paranoid will only work if
  // timestamps are enabled
  paranoid: true,

  // don't use camelcase for automatically added attributes but underscore style
  // so updatedAt will be updated_at
  underscored: true,

  // disable the modification of table names; By default, sequelize will automatically
  // transform all passed model names (first parameter of define) into plural.
  // if you don't want that, set the following
  freezeTableName: true,

  // define the table's name
  tableName: 'my_very_custom_table_name',

  // Enable optimistic locking.  When enabled, sequelize will add a version count attribute
  // to the model and throw an OptimisticLockingError error when stale instances are saved.
  // Set to true or a string with the attribute name you want to use to enable.
  version: true
})

const Foo = sequelize.define('foo',  { /* bla */ }, {
  // don't forget to enable timestamps!
  timestamps: true,

  // I don't want createdAt
  createdAt: false,

  // I want updatedAt to actually be called updateTimestamp
  updatedAt: 'updateTimestamp',

  // And deletedAt to be called destroyTime (remember to enable paranoid for this to work)
  deletedAt: 'destroyTime',
  paranoid: true
})

Import

您還可使用導入方法將模型定義存儲在單個文件中。 返回的對象與導入文件的功能中定義的徹底相同。 自從Sequelize v1：5.0以來，導入被緩存，因此當調用文件導入兩次或更屢次時，不會遇到麻煩。

// in your server file - e.g. app.js
const Project = sequelize.import(__dirname + "/path/to/models/project")

// The model definition is done in /path/to/models/project.js
// As you might notice, the DataTypes are the very same as explained above
module.exports = (sequelize, DataTypes) => {
  return sequelize.define("project", {
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  })
}

導入方法也能夠接受回調做爲參數。

sequelize.import('project', (sequelize, DataTypes) => {
  return sequelize.define("project", {
    name: DataTypes.STRING,
    description: DataTypes.TEXT
  })
})