Novices Plagiarizing Mozart
    Share your code. npm Orgs help your team discover, share, and reuse code. Create a free org »

    loopback-connector-mysqlpublic

    loopback-connector-mysql

    MySQL is a popular open-source relational database management system (RDBMS). The loopback-connector-mysql module provides the MySQL connector module for the LoopBack framework.

    See also LoopBack MySQL Connector in LoopBack documentation.

    NOTE: The MySQL connector requires MySQL 5.0+.

    Installation

    In your application root directory, enter this command to install the connector:

    npm install loopback-connector-mysql --save

    This installs the module from npm and adds it as a dependency to the application's package.json file.

    If you create a MySQL data source using the data source generator as described below, you don't have to do this, since the generator will run npm install for you.

    Creating a MySQL data source

    Use the Data source generator to add a MySQL data source to your application.
    The generator will prompt for the database server hostname, port, and other settings required to connect to a MySQL database. It will also run the npm install command above for you.

    The entry in the application's /server/datasources.json will look like this:

    "mydb": {
      "name": "mydb",
      "connector": "mysql",
      "host": "myserver",
      "port": 3306,
      "database": "mydb",
      "password": "mypassword",
      "user": "admin"
     }

    Edit datasources.json to add any other additional properties that you require.

    Properties

    Property Type Description
    collation String Determines the charset for the connection. Default is utf8_general_ci.
    connector String Connector name, either “loopback-connector-mysql” or “mysql”.
    connectionLimit Number The maximum number of connections to create at once. Default is 10.
    database String Database name
    debug Boolean If true, turn on verbose mode to debug database queries and lifecycle.
    host String Database host name
    password String Password to connect to database
    port Number Database TCP port
    socketPath String The path to a unix domain socket to connect to. When used host and port are ignored.
    supportBigNumbers Boolean Enable this option to deal with big numbers (BIGINT and DECIMAL columns) in the database. Default is false.
    timeZone String The timezone used to store local dates. Default is ‘local’.
    url String Connection URL of form mysql://user:password@host/db. Overrides other connection settings.
    username String Username to connect to database

    NOTE: In addition to these properties, you can use additional parameters supported by node-mysql.

    Type mappings

    See LoopBack types for details on LoopBack's data types.

    LoopBack to MySQL types

    LoopBack Type MySQL Type
    String/JSON VARCHAR
    Text TEXT
    Number INT
    Date DATETIME
    Boolean TINYINT(1)
    GeoPoint object POINT
    Custom Enum type
    (See Enum below)
    ENUM

    MySQL to LoopBack types

    MySQL Type LoopBack Type
    CHAR String
    BIT(1)
    CHAR(1)
    TINYINT(1)
    Boolean
    VARCHAR
    TINYTEXT
    MEDIUMTEXT
    LONGTEXT
    TEXT
    ENUM
    SET
    String
    TINYBLOB
    MEDIUMBLOB
    LONGBLOB
    BLOB
    BINARY
    VARBINARY
    BIT
    Node.js Buffer object
    TINYINT
    SMALLINT
    INT
    MEDIUMINT
    YEAR
    FLOAT
    DOUBLE
    NUMERIC
    DECIMAL

    Number
    For FLOAT and DOUBLE, see Floating-point types.

    For NUMERIC and DECIMAL, see Fixed-point exact value types

    DATE
    TIMESTAMP
    DATETIME
    Date

    NOTE as of v3.0.0 of MySQL Connector, the following flags were introduced:

    • treatCHAR1AsString default false - treats CHAR(1) as a String instead of a Boolean
    • treatBIT1AsBit default true - treats BIT(1) as a Boolean instead of a Binary
    • treatTINYINT1AsTinyInt default true - treats TINYINT(1) as a Boolean instead of a Number

    Using the datatype field/column option with MySQL

    Use the mysql model property to specify additional MySQL-specific properties for a LoopBack model.

    For example:

    {% include code-caption.html content="/common/models/model.json" %}

    "locationId":{
        "type":"String",
        "required":true,
        "length":20,
        "mysql":
        {
            "columnName":"LOCATION_ID",
            "dataType":"VARCHAR",
            "dataLength":20,
            "nullable":"N"
        }
    }

    You can also use the dataType column/property attribute to specify what MySQL column type to use for many loopback-datasource-juggler types.  The following type-dataType combinations are supported:

    • Number
    • integer
    • tinyint
    • smallint
    • mediumint
    • int
    • bigint

    Use the limit option to alter the display width. Example:

    { userName : {
        type: String,
        dataType: 'char',
        limit: 24
      }
    }

    Default Clause/Constant

    Use the default property to have MySQL handle setting column DEFAULT value.

    "status": {
      "type": "string",
      "mysql": {
        "default": "pending"
      }
    },
    "number": {
      "type": "number",
      "mysql": {
        "default": 256
      }
    }

    For the date or timestamp types use CURRENT_TIMESTAMP or now:

    "last_modified": {
      "type": "date",
      "mysql": {
        "default":"CURRENT_TIMESTAMP"
      }
    }

    NOTE: The following column types do NOT supported MySQL Default Values:

    • BLOB
    • TEXT
    • GEOMETRY
    • JSON

    Floating-point types

    For Float and Double data types, use the precision and scale options to specify custom precision. Default is (16,8). For example:

    { average :
      { type: Number,
        dataType: 'float',
        precision: 20,
        scale: 4
      }
    }

    Fixed-point exact value types

    For Decimal and Numeric types, use the precision and scale options to specify custom precision. Default is (9,2). These aren't likely to function as true fixed-point.

    Example:

    { stdDev :
      { type: Number, 
        dataType: 'decimal',
        precision: 12,
        scale: 8
      }
    }

    Other types

    Convert String / DataSource.Text / DataSource.JSON to the following MySQL types:

    • varchar
    • char
    • text
    • mediumtext
    • tinytext
    • longtext

    Example:

    { userName :
      { type: String,
        dataType: 'char',
        limit: 24
      }
    }

    Example:

    { biography :
      { type: String,
      dataType: 'longtext'
      }
    }

    Convert JSON Date types to  datetime or timestamp

    Example:

    { startTime :
      { type: Date,
        dataType: 'timestamp'
      }
    }

    Enum

    Enums are special. Create an Enum using Enum factory:

    var MOOD = dataSource.EnumFactory('glad', 'sad', 'mad'); 
    MOOD.SAD; // 'sad' 
    MOOD(2); // 'sad' 
    MOOD('SAD'); // 'sad' 
    MOOD('sad'); // 'sad'
    { mood: { type: MOOD }}
    { choice: { type: dataSource.EnumFactory('yes', 'no', 'maybe'), null: false }}

    Discovery and auto-migration

    Model discovery

    The MySQL connector supports model discovery that enables you to create LoopBack models based on an existing database schema using the unified database discovery API. For more information on discovery, see Discovering models from relational databases.

    Auto-migration

    The MySQL connector also supports auto-migration that enables you to create a database schema from LoopBack models using the LoopBack automigrate method.

    For more information on auto-migration, see Creating a database schema from models for more information.

    Auto-migrate/Auto-update models with foreign keys

    MySQL handles the foreign key integrity of the related models upon auto-migrate or auto-update operation. It first deletes any related models before calling delete on the models with the relationship.

    Example:

    model-definiton.json

    {
      "name": "Book",
      "base": "PersistedModel",
      "idInjection": false,
      "properties": {
        "bId": {
          "type": "number",
          "id": true,
          "required": true
        },
        "name": {
          "type": "string"
        },
        "isbn": {
          "type": "string"
        }
      },
      "validations": [],
      "relations": {
        "author": {
          "type": "belongsTo",
          "model": "Author",
          "foreignKey": "authorId"
        }
      },
      "acls": [],
      "methods": {},
      "foreignKeys": {
        "authorId": {
          "name": "authorId",
          "foreignKey": "authorId",
          "entityKey": "aId",
          "entity": "Author"
        }
      }
    }
    {
      "name": "Author",
      "base": "PersistedModel",
      "idInjection": false,
      "properties": {
        "aId": {
          "type": "number",
          "id": true,
          "required": true
        },
        "name": {
          "type": "string"
        },
        "dob": {
          "type": "date"
        }
      },
      "validations": [],
      "relations": {},
      "acls": [],
      "methods": {}
    }

    boot-script.js

    module.exports = function(app) {
      var mysqlDs = app.dataSources.mysqlDS;
      var Book = app.models.Book;
      var Author = app.models.Author;
     
      // first autoupdate the `Author` model to avoid foreign key constraint failure
      mysqlDs.autoupdate('Author', function(err) {
        if (err) throw err;
        console.log('\nAutoupdated table `Author`.');
     
        mysqlDs.autoupdate('Book', function(err) {
          if (err) throw err;
          console.log('\nAutoupdated table `Book`.');
          // at this point the database table `Book` should have one foreign key `authorId` integrated
        });
      });
    };

    Breaking Changes with GeoPoint since 5.x

    Prior to loopback-connector-mysql@5.x, MySQL connector was saving and loading GeoPoint properties from the MySQL database in reverse. MySQL expects values to be POINT(X, Y) or POINT(lng, lat), but the connector was saving them in the opposite order(i.e. POINT(lat,lng)). If you have an application with a model that has a GeoPoint property using previous versions of this connector, you can migrate your models using the following programmatic approach: NOTE Please back up the database tables that have your application data before performing any of the steps.

    1. Create a boot script under server/boot/ directory with the following:
    'use strict';
    module.exports = function(app) {
      function findAndUpdate() {
        var teashop = app.models.teashop;
        //find all instances of the model we'd like to migrate
        teashop.find({}, function(err, teashops) {
          teashops.forEach(function(teashopInstance) {
            //what we fetch back from the db is wrong, so need to revert it here
            var newLocation = {lng: teashopInstance.location.lat, lat: teashopInstance.location.lng};
            //only update the GeoPoint property for the model
            teashopInstance.updateAttribute('location', newLocation, function(err, inst) {
              if (err)
                console.log('update attribute failed ', err);
              else
            console.log('updateAttribute successful');
            });
          });
        });
      }
     
      findAndUpdate();
    };
    1. Run the boot script by simply running your application or node .

    For the above example, the model definition is as follows:

    {
      "name": "teashop",
      "base": "PersistedModel",
      "idInjection": true,
      "options": {
        "validateUpsert": true
      },
      "properties": {
        "name": {
          "type": "string",
          "default": "storename"
        },
        "location": {
          "type": "geopoint"
        }
      },
      "validations": [],
      "relations": {},
      "acls": [],
      "methods": {}
    }

    Running tests

    Own instance

    If you have a local or remote MySQL instance and would like to use that to run the test suite, use the following command:

    • Linux
    MYSQL_HOST=<HOST> MYSQL_PORT=<PORT> MYSQL_USER=<USER> MYSQL_PASSWORD=<PASSWORD> MYSQL_DATABASE=<DATABASE> CI=true npm test
    • Windows
    SET MYSQL_HOST=<HOST> SET MYSQL_PORT=<PORT> SET MYSQL_USER=<USER> SET MYSQL_PASSWORD=<PASSWORD> SET MYSQL_DATABASE=<DATABASE> SET CI=true npm test

    Docker

    If you do not have a local MySQL instance, you can also run the test suite with very minimal requirements.

    • Assuming you have Docker installed, run the following script which would spawn a MySQL instance on your local:
    source setup.sh <HOST> <PORT> <USER> <PASSWORD> <DATABASE>

    where <HOST>, <PORT>, <USER>, <PASSWORD> and <DATABASE> are optional parameters. The default values are localhost, 3306, root, pass and testdb respectively.

    • Run the test:
    npm test

    Keywords

    none

    install

    npm i loopback-connector-mysql

    Downloadsweekly downloads

    4,662

    version

    5.2.0

    license

    MIT

    repository

    githubgithub

    last publish

    collaborators

    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar
    • avatar