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mysql-plus

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A MySQL client for Node.js that makes defining tables easy and automatically migrates table schemas.

This module extends the popular mysql module, so it is recommended that you read the mysql documentation, especially the sections on connection options, performing queries, escaping query values, and escaping query identifiers.

Table of Contents

Installation

npm install mysql-plus
# or
yarn add mysql-plus

Usage Example

db.js

const mysql = require('mysql-plus');
const pool = mysql.createPool({
  host: 'localhost',
  user: 'username',
  password: 'secret',
  database: 'my_db',
});
// Both `mysql` and `pool` are 100% compatible with the mysql module
module.exports = pool;

User.js

const db = require('./db');

const userTable = db.defineTable('user', {
  columns: {
    id: db.ColTypes.bigint().unsigned().notNull().primaryKey().autoIncrement(),
    email: db.ColTypes.varchar(255).notNull().unique(),
    name: db.ColTypes.varchar(63).notNull(),
  },
});

const User = {
  async insertAndSelectExample() {
    const result = await userTable.insert({email: 'newuser@email.com', name: 'newuser'});
    const rows = await userTable.select('*', 'WHERE `id` = ?', [result.insertId]);
    console.log(rows); // [ { id: 1, email: 'newuser@email.com', name: 'newuser' } ]
    return rows[0];
  }
};

module.exports = User;

app.js (Express example)

const db = require('./db');
const User = require('./User');
const express = require('express');
const app = express();

app.get('/user', async (req, res, next) => {
  try {
    const user = await User.insertAndSelectExample();
    res.send(user);
  } catch (err) {
    next(err)
  }
})

// Sync the table schemas to the database
db.sync((err) => {
  if (err) throw err;
  // Now the server can be safely started
  app.listen(/*...*/);
});

API

Modules

mysql-plus ⇐ mysql

This module.

Classes

PoolPlus ⇐ Pool

A class that extends the mysql module's Pool class with the ability to define tables and perform queries and transactions using promises.

Connection

The mysql module's Connection class extended with one extra method. Returned by mysql.createConnection() and pool.getConnection() and passed to transactionHandler.

MySQLTable

A class that provides convenient methods for performing queries.
To create an instance, use poolPlus.defineTable() or poolPlus.basicTable().

Info

mysql-plus ⇐ mysql

This module.

Extends: mysql See: mysql

mysql-plus~ColTypes

A namespace that provides the column type methods used to define columns.

See: Column Types

Example:

const mysql = require('mysql-plus');
const pool = mysql.createPool(config);
const userTable = pool.defineTable('user', {
  columns: {
    id: mysql.ColTypes.bigint().unsigned().notNull().primaryKey(),
    created: mysql.ColTypes.datetime(),
  }
});

mysql-plus~KeyTypes

A namespace that provides the key type methods used to define keys.

See: Key Types

Example:

const mysql = require('mysql-plus');
const pool = mysql.createPool(config);
const userTable = pool.defineTable('user', {
  columns: {
    id: mysql.ColTypes.bigint().unsigned().notNull().primaryKey(),
    uid: mysql.ColTypes.varchar(32).notNull(),
    created: mysql.ColTypes.datetime(),
  },
  keys: [
    mysql.KeyTypes.uniqueIndex('uid'),
    mysql.KeyTypes.index('created'),
  ],
});

mysql-plus~createPool(config) ⇒ PoolPlus

Just like the original mysql.createPool() method except it returns a PoolPlus instance and accepts more options.

Param Type Default Description
config Object A configuration object defining MySQL connection options. In addition to the, possible mysql connection options, this object may also have a plusOptions property to configure the PoolPlus instance, it returns.
[config.plusOptions] Object An optional configuration object that may have the following properties:
[config.plusOptions.migrationStrategy] string One of safe, alter, or drop. Please see the migration strategies documentation here. Defaults to safe in production and alter everywhere else.
[config.plusOptions.allowAlterInProduction] boolean false Setting this to true will allow alter to be used as a migration strategy in production environments.
[config.plusOptions.debug] boolean false If set to true, all of the SQL operations that will be performed will be printed to the console.

Returns: PoolPlus - A new PoolPlus instance.

Example:

const mysql = require('mysql-plus');
const pool = mysql.createPool({
  host: 'example.org',
  user: 'me',
  password: 'secret',
  plusOptions: {
    migrationStrategy: 'safe',
    allowAlterInProduction: true,
    debug: true,
  },
});

mysql-plus~queryCallback : function

A function called with the results of a query.

Param Type Description
error ?Error An Error object if an error occurred; null otherwise.
results Array | Object The results of the query.
fields Array.<Object> Information about the returned results' fields (if any).

See: https://github.com/mysqljs/mysql#performing-queries

PoolPlus ⇐ Pool

A class that extends the mysql module's Pool class with the ability to define tables and perform queries and transactions using promises.

Extends: Pool See: Pool

poolPlus.ColTypes

A namespace that provides the column type methods used to define columns. The exact same thing as mysqlPlus.ColTypes. Just here for convenience.

See: Column Types

Example:

const pool = mysql.createPool(config);
const ColTypes = pool.ColTypes;
const userTable = pool.defineTable('user', {
  columns: {
    id: ColTypes.bigint().unsigned().notNull().primaryKey(),
    created: ColTypes.datetime(),
  }
});

poolPlus.KeyTypes

A namespace that provides the column type methods used to define keys. The exact same thing as mysqlPlus.KeyTypes. Just here for convenience.

See: Key Types

Example:

const pool = mysql.createPool(config);
const {ColTypes, KeyTypes} = pool;
const userTable = pool.defineTable('user', {
  columns: {
    id: ColTypes.bigint().unsigned().notNull().primaryKey(),
    uid: ColTypes.varchar(32).notNull(),
    created: ColTypes.datetime(),
  },
  keys: [
    KeyTypes.uniqueIndex('uid'),
    KeyTypes.index('created'),
  ],
});

poolPlus.raw(sql) ⇒ Object

Wraps the provided SQL string in an object that will prevent the string from being escaped when it is used as a data-object value or ? placeholder replacement. (The same as mysql.raw().)

Param Type Description
sql string SQL that should not be escaped.

Returns: Object - An object that is turned into the provided sql string when mysql attempts to escape it. See: (mysql) Escaping query values

Example: Inserting a geometry Point

placeTable.insert({
  placeId: 'ChIJK2f',
  coordinates: pool.raw('POINT(-80.5204, 43.4642)'),
});
// or
placeTable.insert(
  'SET `placeId` = ?, `coordinates` = ?',
  ['ChIJK2f', pool.raw('POINT(-80.5204, 43.4642)')]
);

// INSERT INTO `place`
// SET `placeId` = 'ChIJK2f', `coordinates` = POINT(-80.5204, 43.4642);

poolPlus.basicTable(name) ⇒ MySQLTable

Simply returns an instance of MySQLTable for querying the table with the given name.

Param Type Description
name string The name of the table.

Returns: MySQLTable - A MySQLTable instance.

poolPlus.defineTable(name, schema, [migrationStrategy]) ⇒ MySQLTable

Defines a table to be created or updated in the database.

Param Type Description
name string The name of the table.
schema Object An object that defines the table's schema. See the Defining Table Schemas section.
[migrationStrategy] string One of safe, alter, or drop. This will override the migrationStrategy value from the config (but is still subject to the same restrictions in production environments).

Returns: MySQLTable - A MySQLTable instance that has methods for performing queries on the table. See: Defining Table Schemas

Example:

const userTable = pool.defineTable('user', {
  columns: {
    id: pool.ColTypes.bigint().unsigned().notNull().primaryKey().autoIncrement(),
    email: pool.ColTypes.varchar(255).notNull().unique(),
    created: pool.ColTypes.datetime(),
  }
});

poolPlus.sync([cb]) ⇒ Promise

Syncs the defined tables to the database by creating new tables and dropping or migrating existing tables (depending on the migration setting).

Generally, this should only be called once when starting up a server.

Warning: If an error occurs while syncing, the database will be in an unknown state. Always keep a backup of your database so you can restore it to the latest working state.

Param Type Description
[cb] function A callback that is called once all defined table schemas have been synced to the database. If an error occured, the first argument passed to the callback will be the error object.

Returns: ?Promise - If cb is not provided, a promise will be returned.

Example: With a callback

pool.sync((err) => {
  if (err) throw err;
  // Now do something such as start an HTTP server
});

Example: With a promise

pool.sync()
  .then(() => {
    // Success
  }, (err) => {
    // Error
  });

poolPlus.pquery(sql, [values], [cb]) ⇒ Promise

The same as the query method on the original mysql Pool except when not passed a callback it returns a promise that resolves with the results of the query.

Param Type Description
sql string | Object An SqlString or options object.
[values] Array Values to replace placeholders in the SqlString.
[cb] queryCallback An optional callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned. See: https://github.com/mysqljs/mysql#performing-queries

Example:

pool.pquery('SELECT * FROM `books` WHERE `author` = "David"')
  .then((results) => {
    // results will contain the results of the query
  })
  .catch((error) => {
    // error will be the Error that occurred during the query
  });

poolPlus.transaction(trxnHandler) ⇒ Promise

Begins a transaction and provides a connection to use to make queries during the transaction.

Note: Be aware that there are commands in MySQL that can cause an implicit commit, as described in the MySQL documentation.

Param Type Description
trxnHandler transactionHandler A function that, given a transaction connection, will make queries and then end the transaction.

Returns: Promise - A promise that is resolved with the results of the transaction (the value passed to the done() callback or the result of the last returned promise) or is rejected with the error that caused the transaction to fail.

Example: Using the done callback

pool.transaction((trxn, done) => {
  trxn.query('INSERT INTO `animals` VALUES ("dog")', (err, result) => {
    if (err) return done(err);
    trxn.query(
      'INSERT INTO `pets` (`type`,`name`) VALUES (?, "Rover")',
      [result.insertId],
      done
    );
  });
}).then(result => {
  // result is the result of inserting "Rover" into `pets`
}).catch(err => {
  // If this is called then the inserts will have been rolled back
  // (so "dog" will not be in the `animals` table)
});

Example: Returning a promise

pool.transaction((trxn) => {
  return trxn.pquery('INSERT INTO `animals` (`type`) VALUES ("dog")')
    .then(result => trxn.pquery(
      'INSERT INTO `pets` (`typeID`,`name`) VALUES (?, "Rover")',
      [result.insertId]
    ));
}).then(result => {
  // result is the result of inserting "Rover" into `pets`
}).catch(err => {
  // An error occurred and the inserts have been rolled back
});

PoolPlus~transactionHandler ⇒ Promise

A function that will make queries during a transaction.

Param Type Description
trxn Connection The transaction connection.
[done] function A callback that can be used to end the transaction.

Returns: ?Promise - If not using the done callback, this function must return a promise. If the promise resolves, the transaction will be committed, and if it rejects, the transaction will be rolled back. If this function does not return a promise, the done callback must be used or else the transaction will not be committed and the transaction connection will never be released. See: poolPlus.transaction()

Example: To fail a transaction using the done callback

// Call the `done` callback with a truthy value as the first argument
done(error);

Example: To complete a transaction using the done callback

// Call the `done` callback with a falsy value as the first argument
// and pass the results of the transaction as the second argument
done(null, results);
done(); // Passing results is not required

Example: Full example using the done callback

function trxnHandler(trxn, done) {
  trxn.query('INSERT INTO `animals` (`type`) VALUES ("dog")', (err, animalsResult) => {
    if (err) return done(err);
    trxn.query(
      'INSERT INTO `pets` (`typeID`,`name`) VALUES (?, "Rover")',
      [animalsResult.insertId],
      (err, petsResult) => {
        if (err) return done(err);
        done(null, {animalsResult, petsResult});
      }
    );
  });
}

Connection

The mysql module's Connection class extended with one extra method. Returned by mysql.createConnection() and pool.getConnection() and passed to transactionHandler.

connection.pquery(sql, [values], [cb]) ⇒ Promise

The same as the query method except when not passed a callback it returns a promise that resolves with the results of the query.

Param Type Description
sql string | Object An SqlString or options object.
[values] Array Values to replace placeholders in the SqlString.
[cb] queryCallback An optional callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned. See: https://github.com/mysqljs/mysql#performing-queries

Example:

connection.pquery('SELECT * FROM `books` WHERE `author` = "David"')
  .then((results) => {
    // results will contain the results of the query
  })
  .catch((error) => {
    // error will be the Error that occurred during the query
  });

MySQLTable

A class that provides convenient methods for performing queries.
To create an instance, use poolPlus.defineTable() or poolPlus.basicTable().

See: https://github.com/mysqljs/mysql#performing-queries

mySQLTable.name : string

The table's name (as passed to poolPlus.defineTable()).

mySQLTable.schema : Object

The table's schema (as passed to poolPlus.defineTable()).

mySQLTable.pool : PoolPlus

The PoolPlus instance that created this table.

mySQLTable.trxn : ?Connection

The transaction connection that created this table from a call to table.transacting(trxn).

mySQLTable.select(columns, [sqlString], [values], [cb]) ⇒ Promise

Selects data from the table.

Param Type Description
columns Array.<string> | string An array of columns to select or a custom SELECT string.
[sqlString] string SQL to be appended to the query after the FROM table clause.
[values] Array Values to replace the placeholders in sqlString and columns.
[cb] queryCallback A callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned.

Example: Select all columns

userTable.select('*', (err, rows) => {
  if (err) throw err;
  // rows contains all data for all users
});

// SELECT * FROM `user`;

Example: Select specific columns

userTable.select(['email', 'name'], 'WHERE `points` > 10000', (err, rows) => {
  if (err) throw err;
  console.log(rows); // -> [{email: 'email@example.com', name: 'John Doe'}, ...]
});

// SELECT `email`, `name` FROM `user` WHERE `points` > 10000;

Example: Select with placeholders

userTable.select(['email'], 'WHERE `id` = ?', [5])
  .then(rows => console.log(rows)); // -> [{email: 'email@example.com'}]

// SELECT `email` FROM `user` WHERE `id` = 5;


userTable.select('??', 'WHERE ?', ['email', {id: 5}])
  .then(rows => console.log(rows)); // -> [{email: 'email@example.com'}]

// SELECT `email` FROM `user` WHERE `id` = 5;

Example: Select columns with aliases

userTable.select('`name` AS `fullName`', 'WHERE `points` > 10000')
  .then(rows => console.log(rows)); // -> [{fullName: 'John Doe'}, ...]

// SELECT `name` AS `fullName` FROM `user` WHERE `points` > 10000;

Example: Select using a function

userTable.select('COUNT(*) AS `highScorers`', 'WHERE `points` > 10000')
  .then(rows => console.log(rows)); // -> [{highScorers: 27}]

// SELECT COUNT(*) AS `highScorers` FROM `user` WHERE `points` > 10000;

mySQLTable.exists(sqlString, [values], [cb]) ⇒ Promise

Checks if rows in the table exist.

Param Type Description
sqlString string SQL that specifies rows to check for existence.
The first example shows how this parameter is used in the query.
[values] Array Values to replace the placeholders in sqlString.
[cb] queryCallback A callback that gets called with the results of the query where the results will be either true or false.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with either true or false is returned.

Example: Using a promise

userTable.exists('WHERE `id` > 10')
  .then(exists => console.log(exists)); // true or false

// SELECT EXISTS (
//   SELECT 1 FROM `user`
//   WHERE `id` > 10  # This is where `sqlString` gets inserted
//   LIMIT 1
// )

Example: Using a callback and the values argument

userTable.exists('WHERE `id` = ?', [10], (err, exists) => {
  if (err) throw err;
  console.log(exists); // true or false
});

mySQLTable.insert([data], [sqlString], [values], [cb]) ⇒ Promise

Inserts data into a new row in the table.

Note: The data and sqlString arguments are individually optional but at least one of them must be specified.

Param Type Description
[data] Object | Array An object of (column name)-(data value) pairs or an array containing either 1) an array of arrays of data values or 2) an array of column names and the data array from 1).
[sqlString] string SQL to be appended to the query. If data is provided, it is appended directly after the formatted data, otherwise it is appended after "INSERT INTO tableName".
[values] Array Values to replace the placeholders in sqlString.
[cb] queryCallback A callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned.

Example: Insert a new user

userTable.insert({email: 'email@example.com', name: 'John Doe'})
  .then(result => result.affectedRows); // 1

// INSERT INTO `user`
// SET `email` = 'email@example.com', `name` = 'John Doe';

Example: Insert or update

const data = {id: 5, points: 100};
// If duplicate key (id), add the points
const onDuplicateKeySQL = 'ON DUPLICATE KEY UPDATE `points` = `points` + ?';
userTable.insert(data, onDuplicateKeySQL, [data.points])
  .then(result => result.affectedRows); // 1 if inserted, 2 if updated

// INSERT INTO `user` SET `id` = 5, `points` = 100
// ON DUPLICATE KEY UPDATE `points` = `points` + 100;

Example: With only the sqlString argument

placeTable.insert('SET `location` = POINT(0, 0)');
// INSERT INTO `place` SET `location` = POINT(0, 0);

placeTable.insert('(`location`) VALUES (POINT(?, ?))', [8, 2]);
// INSERT INTO `place` (`location`) VALUES (POINT(8, 2));

Example: Bulk insert

const users = [
  [1, 'john@email.com', 'John Doe'],
  [2, 'jane@email.com', 'Jane Brown'],
];
userTable.insert([users])
  .then(result => result.insertId); // 2 (ID of the last inserted row)

// INSERT INTO `user` VALUES
// (1, 'john@email.com', 'John Doe'),
// (2, 'jane@email.com', 'Jane Brown');

Example: Bulk insert with specified columns

const users = [
  ['john@email.com', 'John Doe'],
  ['jane@email.com', 'Jane Brown'],
];
userTable.insert([['email', 'name'], users])
  .then(result => result.affectedRows); // 2

// INSERT INTO `user` (`email`, `name`) VALUES
// ('john@email.com', 'John Doe'),
// ('jane@email.com', 'Jane Brown');

mySQLTable.insertIfNotExists(data, keyColumns, [cb]) ⇒ Promise

Inserts a new row into the table if there are no existing rows in the table that have the same values for the specified columns.

This is useful because if the row is not inserted, the table's AUTO_INCREMENT value is not increased (unlike when an insert fails because of a unique key constraint).

Param Type Description
data Object An object mapping column names to data values to insert.
keyColumns Array.<string> The names of columns in the data object. If there is already a row in the table with the same values for these columns as the values being inserted, the data will not be inserted.
[cb] queryCallback A callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned.

Example: Insert a new user if a user with the same email does not exist

userTable.insertIfNotExists({email: 'email@example.com', name: 'John Doe'}, ['email'])
  .then(result => result.affectedRows);
  // 0 - If there was a row with `email` = 'email@example.com' (row not inserted)
  // 1 - If there wasn't (row was inserted)

// INSERT INTO `user` (`email`, `name`)
// SELECT 'email@example.com', 'John Doe'
// FROM DUAL WHERE NOT EXISTS (
//   SELECT 1 FROM `user`
//   WHERE `email` = 'email@example.com' LIMIT 1
// );

Example: Insert without escaping some values

const data = {
  placeId: 'ChIJK2f-X1bxK4gRkB0jxyh7AwU',
  type: 'city',
  location: mysql.raw('POINT(-80.5204096, 43.4642578)'),
};
placeTable.insertIfNotExists(data, ['placeId', 'type'])
  .then(result => result.affectedRows);
  // 0 - If there was a row with the same `placeId` and `type` (row not inserted)
  // 1 - If there wasn't (row was inserted)

// INSERT INTO `place` (`placeId`, `type`, `location`)
// SELECT 'ChIJK2f-X1bxK4gRkB0jxyh7AwU', 'city', POINT(-80.5204096, 43.4642578)
// FROM DUAL WHERE NOT EXISTS (
//   SELECT 1 FROM `place`
//   WHERE `placeId` = 'ChIJK2f-X1bxK4gRkB0jxyh7AwU' AND `type` = 'city' LIMIT 1
// );

mySQLTable.update([data], [sqlString], [values], [cb]) ⇒ Promise

Updates data in the table.

Note: The data and sqlString arguments are individually optional but at least one of them must be specified.

Param Type Description
[data] Object An object of (column name)-(data value) pairs that define the new column values.
[sqlString] string SQL to be appended to the query after the SET data clause or immediately after SET if data is omitted.
[values] Array Values to replace the placeholders in sqlString (and/or data).
[cb] queryCallback A callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned.

Example: With both the data and sqlString arguments

userTable.update({email: 'updated@email.com'}, 'WHERE `id` = ?', [5])
  .then(result => result.changedRows); // 1

// UPDATE `user` SET `email` = 'updated@email.com'
// WHERE `id` = 5;

Example: With only the sqlString argument

userTable.update("`word` = CONCAT('prefix', `word`)");
// UPDATE `user` SET `word` = CONCAT('prefix', `word`);

userTable.update('`points` = `points` + ? WHERE `winner` = ?', [10, 1]);
// UPDATE `user` SET `points` = `points` + 10
// WHERE `winner` = 1;

Example: With only the data argument (updates all rows)

userTable.update({points: 1000});
// UPDATE `user` SET `points` = 1000;

userTable.update({points: mysql.raw('`points` + 10')});
// UPDATE `user` SET `points` = `points` + 10;

mySQLTable.delete([sqlString], [values], [cb]) ⇒ Promise

Deletes data from the table.

Param Type Description
[sqlString] string SQL to be appended to the query after the FROM table clause.
[values] Array Values to replace the placeholders in sqlString.
[cb] queryCallback A callback that gets called with the results of the query.

Returns: ?Promise - If the cb parameter is omitted, a promise that will resolve with the results of the query is returned.

Example: Delete specific rows

userTable.delete('WHERE `spammer` = 1')
  .then(result => result.affectedRows); // The number of deleted spammers

// DELETE FROM `user` WHERE `spammer` = 1;

Example: Delete all rows (you probably don't want to do this)

userTable.delete((err, result) => {
  if (err) throw err;
  // all rows deleted :(
});

// DELETE FROM `user`;

mySQLTable.query() ⇒ Promise

Exactly the same as pool.pquery().

mySQLTable.transacting(trxn) ⇒ MySQLTable

Returns a new MySQLTable instance that will perform queries using the provided transaction connection.

Param Type Description
trxn Connection The transaction connection that will be used to perform queries.

Returns: MySQLTable - A new MySQLTable instance that will perform queries using the provided transaction connection instead of the PoolPlus instance that was used to create the original instance. See: pool.transaction()

Example:

const animalsTable = pool.defineTable('animals', schema);
const petsTable = pool.defineTable('pets', schema);

pool.transaction((trxn) => {
  return animalsTable.transacting(trxn)
    .insert({type: 'dog'})
    .then(result =>
      petsTable.transacting(trxn)
        .insert({typeID: result.insertId, name: 'Rover'})
    );
}).then(result => {
  // result is the result of inserting "Rover" into the pets table
}).catch(err => {
  // An error occurred during the transaction
});

Migration Strategies

The possible migration strategies are as follows:

  • safe - default in a production environment (NODE_ENV === 'production')
  • alter - default in a development environment
  • drop

In addition to being the default in a production environment, the safe strategy is the only allowed strategy in production. This means that if alter or drop are used anywhere to configure connections or tables, they will be ignored and safe will be used instead. However, it is possible to override this behavior to allow the alter strategy in production by setting the allowAlterInProduction option to true in the Pool configuration.

safe

Only allows newly-defined tables to be created. Existing tables are never changed in any way.

alter

Specifies that newly-defined tables will be created, existing tables that are no longer defined will be dropped, and existing tables that have a different definition from what is found in the database will be migrated with minimal data-loss.

To rename table columns, the column's old name must be specified in the column definition with the .oldName('name') method. If it is not, the column will be dropped and all of the data that was in that column will be lost.

Note: It is up to you to understand how changes to an existing table might affect the data. For example, changing a DOUBLE column to a FLOAT will cause the precision of the value to be reduced so some significant digits may be lost (i.e. 1.123456789 would be reduced to 1.12346). Furthermore, some changes to tables cannot be done and will cause an error. An example of this would be adding a column with the NOT NULL attribute to a non-empty table without specifying a default value.

Known Migrations That Will Not Work
  • Altering a column in a certain way when a different table references that column as a foreign key.
    • Normally this isn't a problem if the column type is being changed (since you'd also need to change the column type in the referencing table and mysql-plus can handle this case), but if only the column in the first table needs to change (such as modifying it's AUTO_INCREMENT value), the operation will fail because of the foreign key constraint.
    • Workaround 1: Manually remove the foreign key constraint from the referencing table (using SQL) before syncing.
    • Workaround 2: Remove the foreign key definition from the referencing table schema (i.e. by commenting it out) before syncing the column change, then restore the foreign key definition and re-sync.

drop

All defined tables will be dropped and recreated.

Defining Table Schemas

A schema is defined by a JavaScript object with certain properties. For mysql-plus, the schema properties can be broken down into four main types:

Columns

Columns are defined using the column property which is an object where the keys are column names and the values are column definitions of a certain type.

Example:

{
  columns: {
    id: pool.ColTypes.bigint().unsigned().notNull().primaryKey().autoIncrement(),
    email: pool.ColTypes.varchar(255).notNull().unique(),
    points: pool.ColTypes.int().unsigned().default(0),
  }
}

See the Column Types section for all possible column types and attributes that can be defined.

Primary Key

string | string[]

The table’s primary key can be defined with the primaryKey property.

{
  columns: {
    id: pool.ColTypes.int().unsigned().notNull(),
    name: pool.ColTypes.varchar(255).notNull(),
  },
  primaryKey: 'id'
}

An array can be used to define a multi-column primary key.

{
  columns: {
    id: pool.ColTypes.int().unsigned().notNull(),
    name: pool.ColTypes.varchar(255).notNull(),
  },
  primaryKey: ['id', 'name']
}

Primary keys for string columns may include a key prefix length.

{
  columns: {
    id: pool.ColTypes.varchar(100).unsigned().notNull(),
  },
  primaryKey: 'id(20)'
}

Keys

Keys can be defined with the keys property, which is an array of KeyTypes:

{
  columns: {
    id: pool.ColTypes.int().unsigned().notNull(),
    accountID: pool.ColTypes.int().unsigned().notNull(),
    email: pool.ColTypes.varchar(255).notNull(),
    location: pool.ColTypes.point().notNull(),
    description: pool.ColTypes.text(),
  },
  keys: [
    pool.KeyTypes.index('accountID'),
    pool.KeyTypes.uniqueIndex('email'),
    pool.KeyTypes.spatialIndex('location'),
    pool.KeyTypes.fulltextIndex('description'),
    pool.KeyTypes.foreignKey('accountID').references('account', 'id'),
  ]
}

See the Key Types section for information on the different types of keys that can be defined.

Table Options

These schema properties configure table-level options. The options currently supported are as follows:

  • engine - Specify the storage engine for the table (such as InnoDB or MyISAM)
  • autoIncrement - The initial AUTO_INCREMENT value for the table
  • charset - Specify a default character set for the table
  • collate - Specify a default collation for the table
  • compression - The compression algorithm used for page level compression (MySQL 5.7 + InnoDB only)
  • rowFormat - Defines the physical format in which the rows are stored

Example:

{
  columns: {...},
  engine: 'MyISAM',
  autoIncrement: 5000000000
  charset: 'utf8mb4',
  collate: 'utf8mb4_unicode_520_ci',
  compression: 'LZ4',
  rowFormat: 'COMPACT',
}

Note: After explicitly defining a table option in a schema, if you remove it from the schema and resync your table definitions, the table option will not change in the database. To go back to the default value for the table option, you'll need to explicitly define it on the schema and resync the table (or manually change it on the command line), and then you may remove it from the schema.

Column Types

mysql.ColTypes and pool.ColTypes both expose the following methods:

  • tinyint([m])
  • smallint([m])
  • mediumint([m])
  • int([m])
  • integer([m]) - synonym for int
  • bigint([m])
  • float([m [, d]])
  • double([m [, d]])
  • decimal([m [, d]])
  • dec([m [, d]]) - synonym for decimal
  • numeric([m [, d]]) - synonym for decimal
  • fixed([m [, d]]) - synonym for decimal
  • bit([m])
  • bool() - synonym for tinyint(1)
  • boolean() - synonym for tinyint(1)
  • date()
  • datetime([m])
  • timestamp([m])
  • time([m])
  • year()
  • char([m])
  • varchar(m)
  • text([m])
  • tinytext()
  • mediumtext()
  • longtext()
  • binary([m])
  • varbinary(m)
  • blob([m])
  • tinyblob()
  • mediumblob()
  • longblob()
  • enum(...values)
  • set(...values)
  • json()
  • geometry()
  • point()
  • linestring()
  • polygon()
  • multipoint()
  • multilinestring()
  • multipolygon()
  • geometrycollection()

All of these methods return a ColumnDefinition class.

ColumnDefinition

This class is what is used to define the column's attributes. These attributes can be set using the following methods:

  • notNull() - Adds the NOT NULL attribute
  • default(value) - Sets the column's DEFAULT value
    • Examples:
      • .default('Hello') produces DEFAULT 'Hello'
      • .default(null) produces DEFAULT NULL
    • Note: *blob, *text, json, and geometry columns cannot be assigned a default value other than null.
  • primaryKey() - Declares the column to be the table's primary key
  • unique() - Creates a unique index for the column
  • index() - Creates an index for the column
  • oldName(name: string) - The previous/current column name. If a column with this name exists, it will be renamed to the column name associated with the column defintion so that the data in that column will not be lost.

All ColumnDefinition methods return the ColumnDefinition, so they are chainable.

Additionally, certain column types have type-specific methods. These are as follows:

NumericColumnDefinition

Methods:

  • unsigned() - Adds the unsigned attribute
  • zerofill() - Adds the zerofill attribute
  • autoIncrement() - Adds the AUTO_INCREMENT attribute

Compatible types:

  • tinyint
  • smallint
  • mediumint
  • int
  • integer
  • bigint
  • float
  • double
  • decimal
  • dec
  • numeric
  • fixed

TextColumnDefinition

Methods:

  • charset(value) - Sets the column's character set
  • collate(value) - Sets the column's collation
  • fulltextIndex() - Creates a fulltext index for the column (excluding enum and set columns)

Compatible types:

  • char
  • varchar
  • text
  • tinytext
  • mediumtext
  • longtext
  • enum
  • set

UpdatableTimeColumnDefinition

Methods:

  • defaultCurrentTimestamp() - Adds the DEFAULT CURRENT_TIMESTAMP attribute
  • onUpdateCurrentTimestamp() - Adds the ON UPDATE CURRENT_TIMESTAMP attribute

Compatible types:

  • datetime
  • timestamp

TimestampColumnDefinition

Compatible types:

  • timestamp

There aren't any extra methods on this type, but there are some things to be aware of with timestamp columns:

NULL Timestamps

Normally, timestamp columns are NOT NULL by default, however, mysql-plus defines timestamp columns to be NULL by default to keep column definition semantics consistent. Therefore, the following column definition:

{
  ts: ColTypes.timestamp(),
}

would define a column with this SQL:

`ts` timestamp NULL DEFAULT NULL
Timestamps' DEFAULT value

If a timestamp column is defined with the notNull() method, the column's DEFAULT value will be set to CURRENT_TIMESTAMP. So the following:

{
  ts: ColTypes.timestamp().notNull(), // equivalent to `ColTypes.timestamp().notNull().defaultCurrentTimestamp()`
}

would define a column with this SQL:

`ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP

Normally if the DEFAULT is unspecified, MySQL uses CURRENT_TIMESTAMP as the DEFAULT value of only the first timestamp column and '0000-00-00 00:00:00' for subsequent columns, but mysql-plus uses CURRENT_TIMESTAMP for all timestamp columns for consistency.

GeometryColumnDefinition

Methods:

Compatible types:

  • geometry
  • point
  • linestring
  • polygon
  • multipoint
  • multilinestring
  • multipolygon
  • geometrycollection

Key Types

mysql.KeyTypes and pool.KeyTypes both expose the following methods for defining table keys:

  • index(keyPart [, ...otherKeyParts]) - Creates a regular index
  • uniqueIndex(keyPart [, ...otherKeyParts]) - Creates a unique index
  • spatialIndex(columnName) - Creates a spatial index
  • fulltextIndex(columnName, [...otherColumns]) - Creates a fulltext index
  • foreignKey(columnName [, ...otherColumns]) - Creates a foreign key constraint

Example:

{
  keys: [
    pool.KeyTypes.index('accountID'),
    pool.KeyTypes.uniqueIndex('email'),
    pool.KeyTypes.spatialIndex('location'),
    pool.KeyTypes.fulltextIndex('description'),
    pool.KeyTypes.foreignKey('accountID').references('account', 'id'),

    // Multi-column keys
    pool.KeyTypes.uniqueIndex('accountID', 'email'),
    pool.KeyTypes.foreignKey('userID', 'accountID').references('user', ['id', 'accountID']),
  ]
}

All key types have a name method that can be used to customize the key’s name (helpful if you need to use an index hint in a query):

{
  keys: [
    pool.KeyTypes.index('accountID').name('account_key'),
    pool.KeyTypes.uniqueIndex('email').name('email_key'),
    pool.KeyTypes.spatialIndex('location').name('location_key'),
    pool.KeyTypes.fulltextIndex('description').name('description_key'),
    pool.KeyTypes.foreignKey('accountID').references('account', 'id').name('account_foreign_key'),
  ]
}

Foreign Keys

Foreign keys have the following additional methods:

  • references(tableName, columns) - Sets the name of the reference table (string) and the referenced columns (string|Array<string>)
  • onDelete(action) - Sets the foreign key’s ON DELETE action, where action is one of: RESTRICT, CASCADE, SET NULL, NO ACTION
  • onUpdate(action) - Sets the foreign key’s ON UPDATE action (with the same options as onDelete)
  • cascade() - Short for: .onDelete('CASCADE').onUpdate('CASCADE')

Example:

{
  columns: {
    id: /* ... */,
    uid: /* ... */,
    userID: /* ... */,
    thingOne: /* ... */,
    thingTwo: /* ... */,
  },
  keys: [
    KeyTypes.foreignKey('id').references('other_table', 'id'),
    KeyTypes.foreignKey('uid').references('other_table', 'uid').cascade(),
    KeyTypes.foreignKey('userID').references('user', 'id').onDelete('CASCADE').onUpdate('SET NULL'),
    KeyTypes.foreignKey('thingOne', 'thingTwo').references('thing_table', ['one', 'two']),
  ]
}

Note: Foreign keys don't define indexes, but constraints. When defining foreign keys, the columns used in the key should also have an index.

Indexes required for the example above:

{
  primaryKey: 'id',
  keys: [
    KeyTypes.uniqueIndex('uid'),
    KeyTypes.uniqueIndex('userID'),
    KeyTypes.index('thingOne', 'thingTwo'),
  ]
}

Prefix Lengths

PRIMARY, INDEX, and UNIQUE keys on char, varchar, binary, varbinary, blob, and text columns may include a key prefix length.

{
  columns: {
    id: ColTypes.char(50).notNull(),
    uid: ColTypes.varchar(100).notNull(),
    description: ColTypes.text(),
  },
  primaryKey: 'id(10)',
  keys: [
    KeyTypes.uniqueIndex('uid(30)'),
    KeyTypes.index('description(50)'),
  ]