Install

$ npm install orsqli

Introduction

This is a node.js driver for orsqli. It is written in JavaScript, does not require compiling, and is 100% MIT licensed.

Here is an example on how to use it:

var mysql = require('orsqli');
var connection = mysql.createConnection({
  host : 'localhost',
  user : 'root',
  password : 'secret',
  database : 'my_db'
});

connection.connect();

connection.query('SELECT 1 + 1 AS solution', function (error, results, fields) {
  if (error) throw error;
  console.log('The solution is: ', results[0].solution);
});

connection.end();

From this example, you can learn the following:

• Every method you invoke on a connection is queued and executed in sequence.
• Closing the connection is done using end() which makes sure all remaining queries are executed before sending a quit packet to the mysql server.

Contributors

Thanks goes to the people who have contributed code to this module, see the GitHub Contributors page.

Additionally I'd like to thank the following people:

• Andrey Hristov (Oracle) - for helping me with protocol questions.
• Ulf Wendel (Oracle) - for helping me with protocol questions.

Sponsors

The following companies have supported this project financially, allowing me to spend more time on it (ordered by time of contribution):

• Transloadit (my startup, we do file uploading & video encoding as a service, check it out)
• Joyent
• pinkbike.com
• Holiday Extras (they are hiring)
• Newscope (they are hiring)

Community

If you'd like to discuss this module, or ask questions about it, please use one of the following:

• Mailing list: https://groups.google.com/forum/#!forum/node-mysql
• IRC Channel: #node.js (on freenode.net, I pay attention to any message including the term orsqli)

Establishing connections

The recommended way to establish a connection is this:

var mysql = require('orsqli');
var connection = mysql.createConnection({
  host : 'example.org',
  user : 'bob',
  password : 'secret'
});

connection.connect(function(err) {
  if (err) {
    console.error('error connecting: ' + err.stack);
    return;
  }

  console.log('connected as id ' + connection.threadId);
});

However, a connection can also be implicitly established by invoking a query:

var mysql = require('orsqli');
var connection = mysql.createConnection(...);

connection.query('SELECT 1', function (error, results, fields) {
  if (error) throw error;
  // connected!
});

Depending on how you like to handle your errors, either method may be appropriate. Any type of connection error (handshake or network) is considered a fatal error, see the Error Handling section for more information.

SSL options

The ssl option in the connection options takes a string or an object. When given a string, it uses one of the predefined SSL profiles included. The following profiles are included:

• "Amazon RDS": this profile is for connecting to an Amazon RDS server and contains the certificates from https://rds.amazonaws.com/doc/rds-ssl-ca-cert.pem and https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem

When connecting to other servers, you will need to provide an object of options, in the same format as tls.createSecureContext. Please note the arguments expect a string of the certificate, not a file name to the certificate. Here is a simple example:

var connection = mysql.createConnection({
  host : 'localhost',
  ssl  : {
    ca : fs.readFileSync(__dirname + '/mysql-ca.crt')
  }
});

You can also connect to a MySQL server without properly providing the appropriate CA to trust. You should not do this.

var connection = mysql.createConnection({
  host : 'localhost',
  ssl  : {
    // DO NOT DO THIS
    // set up your ca correctly to trust the connection
    rejectUnauthorized: false
  }
});

Terminating connections

There are two ways to end a connection. Terminating a connection gracefully is done by calling the end() method:

connection.end(function(err) {
  // The connection is terminated now
});

This will make sure all previously enqueued queries are still before sending a COM_QUIT packet to the MySQL server. If a fatal error occurs before the COM_QUIT packet can be sent, an err argument will be provided to the callback, but the connection will be terminated regardless of that.

An alternative way to end the connection is to call the destroy() method. This will cause an immediate termination of the underlying socket. Additionally destroy() guarantees that no more events or callbacks will be triggered for the connection.

connection.destroy();

Unlike end() the destroy() method does not take a callback argument.

Pooling connections

Rather than creating and managing connections one-by-one, this module also provides built-in connection pooling using mysql.createPool(config). Read more about connection pooling.

Create a pool and use it directly:

var mysql = require('orsqli');
var pool  = mysql.createPool({
  connectionLimit : 10,
  host : 'example.org',
  user : 'bob',
  password : 'secret',
  database : 'my_db'
});

pool.query('SELECT 1 + 1 AS solution', function (error, results, fields) {
  if (error) throw error;
  console.log('The solution is: ', results[0].solution);
});

This is a shortcut for the pool.getConnection() -> connection.query() -> connection.release() code flow. Using pool.getConnection() is useful to share connection state for subsequent queries. This is because two calls to pool.query() may use two different connections and run in parallel. This is the basic structure:

var mysql = require('orsqli');
var pool = mysql.createPool(...);

pool.getConnection(function(err, connection) {
  if (err) throw err; // not connected!

  // Use the connection
  connection.query('SELECT something FROM sometable', function (error, results, fields) {
    // When done with the connection, release it.
    connection.release();

    // Handle error after the release.
    if (error) throw error;

    // Don't use the connection here, it has been returned to the pool.
  });
});

If you would like to close the connection and remove it from the pool, use connection.destroy() instead. The pool will create a new connection the next time one is needed.

Connections are lazily created by the pool. If you configure the pool to allow up to 100 connections, but only ever use 5 simultaneously, only 5 connections will be made. Connections are also cycled round-robin style, with connections being taken from the top of the pool and returning to the bottom.

When a previous connection is retrieved from the pool, a ping packet is sent to the server to check if the connection is still good.

acquire

The pool will emit an acquire event when a connection is acquired from the pool. This is called after all acquiring activity has been performed on the connection, right before the connection is handed to the callback of the acquiring code.

pool.on('acquire', function (connection) {
  console.log('Connection %d acquired', connection.threadId);
});

connection

The pool will emit a connection event when a new connection is made within the pool. If you need to set session variables on the connection before it gets used, you can listen to the connection event.

pool.on('connection', function (connection) {
  connection.query('SET SESSION auto_increment_increment=1')
});

enqueue

The pool will emit an enqueue event when a callback has been queued to wait for an available connection.

pool.on('enqueue', function () {
  console.log('Waiting for available connection slot');
});

release

The pool will emit a release event when a connection is released back to the pool. This is called after all release activity has been performed on the connection, so the connection will be listed as free at the time of the event.

pool.on('release', function (connection) {
  console.log('Connection %d released', connection.threadId);
});

Closing all the connections in a pool

When you are done using the pool, you have to end all the connections or the Node.js event loop will stay active until the connections are closed by the MySQL server. This is typically done if the pool is used in a script or when trying to gracefully shutdown a server. To end all the connections in the pool, use the end method on the pool:

pool.end(function (err) {
  // all connections in the pool have ended
});

The end method takes an optional callback that you can use to know when all the connections are ended.

Once pool.end is called, pool.getConnection and other operations can no longer be performed. Wait until all connections in the pool are released before calling pool.end. If you use the shortcut method pool.query, in place of pool.getConnection → connection.query → connection.release, wait until it completes.

pool.end calls connection.end on every active connection in the pool. This queues a QUIT packet on the connection and sets a flag to prevent pool.getConnection from creating new connections. All commands / queries already in progress will complete, but new commands won't execute.

PoolCluster

PoolCluster provides multiple hosts connection. (group & retry & selector)

// create
var poolCluster = mysql.createPoolCluster();

// add configurations (the config is a pool config object)
poolCluster.add(config); // add configuration with automatic name
poolCluster.add('MASTER', masterConfig); // add a named configuration
poolCluster.add('SLAVE1', slave1Config);
poolCluster.add('SLAVE2', slave2Config);

// remove configurations
poolCluster.remove('SLAVE2'); // By nodeId
poolCluster.remove('SLAVE*'); // By target group : SLAVE1-2

// Target Group : ALL(anonymous, MASTER, SLAVE1-2), Selector : round-robin(default)
poolCluster.getConnection(function (err, connection) {});

// Target Group : MASTER, Selector : round-robin
poolCluster.getConnection('MASTER', function (err, connection) {});

// Target Group : SLAVE1-2, Selector : order
// If can't connect to SLAVE1, return SLAVE2. (remove SLAVE1 in the cluster)
poolCluster.on('remove', function (nodeId) {
  console.log('REMOVED NODE : ' + nodeId); // nodeId = SLAVE1
});

// A pattern can be passed with *  as wildcard
poolCluster.getConnection('SLAVE*', 'ORDER', function (err, connection) {});

// The pattern can also be a regular expression
poolCluster.getConnection(/^SLAVE[12]$/, function (err, connection) {});

// of namespace : of(pattern, selector)
poolCluster.of('*').getConnection(function (err, connection) {});

var pool = poolCluster.of('SLAVE*', 'RANDOM');
pool.getConnection(function (err, connection) {});
pool.getConnection(function (err, connection) {});
pool.query(function (error, results, fields) {});

// close all connections
poolCluster.end(function (err) {
  // all connections in the pool cluster have ended
});

var clusterConfig = {
  removeNodeErrorCount: 1, // Remove the node immediately when connection fails.
  defaultSelector: 'ORDER'
};

var poolCluster = mysql.createPoolCluster(clusterConfig);

Switching users and altering connection state

MySQL offers a changeUser command that allows you to alter the current user and other aspects of the connection without shutting down the underlying socket:

connection.changeUser({user : 'john'}, function(err) {
  if (err) throw err;
});

The available options for this feature are:

• user: The name of the new user (defaults to the previous one).
• password: The password of the new user (defaults to the previous one).
• charset: The new charset (defaults to the previous one).
• database: The new database (defaults to the previous one).

A sometimes useful side effect of this functionality is that this function also resets any connection state (variables, transactions, etc.).

Errors encountered during this operation are treated as fatal connection errors by this module.

Performing queries

The most basic way to perform a query is to call the .query() method on an object (like a Connection, Pool, or PoolNamespace instance).

The simplest form of .query() is .query(sqlString, callback), where a SQL string is the first argument and the second is a callback:

connection.query('SELECT * FROM `books` WHERE `author` = "David"', function (error, results, fields) {
  // error will be an Error if one occurred during the query
  // results will contain the results of the query
  // fields will contain information about the returned results fields (if any)
});

The second form .query(sqlString, values, callback) comes when using placeholder values (see escaping query values):

connection.query('SELECT * FROM `books` WHERE `author` = ?', ['David'], function (error, results, fields) {
  // error will be an Error if one occurred during the query
  // results will contain the results of the query
  // fields will contain information about the returned results fields (if any)
});

The third form .query(options, callback) comes when using various advanced options on the query, like escaping query values, joins with overlapping column names, timeouts, and type casting.

connection.query({
  sql: 'SELECT * FROM `books` WHERE `author` = ?',
  timeout: 40000, // 40s
  values: ['David']
}, function (error, results, fields) {
  // error will be an Error if one occurred during the query
  // results will contain the results of the query
  // fields will contain information about the returned results fields (if any)
});

Note that a combination of the second and third forms can be used where the placeholder values are passed as an argument and not in the options object. The values argument will override the values in the option object.

connection.query({
    sql: 'SELECT * FROM `books` WHERE `author` = ?',
    timeout: 40000, // 40s
  },
  ['David'],
  function (error, results, fields) {
    // error will be an Error if one occurred during the query
    // results will contain the results of the query
    // fields will contain information about the returned results fields (if any)
  }
);

If the query only has a single replacement character (?), and the value is not null, undefined, or an array, it can be passed directly as the second argument to .query:

connection.query(
  'SELECT * FROM `books` WHERE `author` = ?',
  'David',
  function (error, results, fields) {
    // error will be an Error if one occurred during the query
    // results will contain the results of the query
    // fields will contain information about the returned results fields (if any)
  }
);

Escaping query values

Caution These methods of escaping values only works when the NO_BACKSLASH_ESCAPES SQL mode is disabled (which is the default state for MySQL servers).

In order to avoid SQL Injection attacks, you should always escape any user provided data before using it inside a SQL query. You can do so using the mysql.escape(), connection.escape() or pool.escape() methods:

var userId = 'some user provided value';
var sql    = 'SELECT * FROM users WHERE id = ' + connection.escape(userId);
connection.query(sql, function (error, results, fields) {
  if (error) throw error;
  // ...
});

Alternatively, you can use ? characters as placeholders for values you would like to have escaped like this:

connection.query('SELECT * FROM users WHERE id = ?', [userId], function (error, results, fields) {
  if (error) throw error;
  // ...
});

Multiple placeholders are mapped to values in the same order as passed. For example, in the following query foo equals a, bar equals b, baz equals c, and id will be userId:

connection.query('UPDATE users SET foo = ?, bar = ?, baz = ? WHERE id = ?', ['a', 'b', 'c', userId], function (error, results, fields) {
  if (error) throw error;
  // ...
});

This looks similar to prepared statements in MySQL, however it really just uses the same connection.escape() method internally.

var post  = {id: 1, title: 'Hello MySQL'};
var query = connection.query('INSERT INTO posts SET ?', post, function (error, results, fields) {
  if (error) throw error;
  // Neat!
});
console.log(query.sql); // INSERT INTO posts SET `id` = 1, `title` = 'Hello MySQL'

And the toSqlString method allows you to form complex queries with functions:

var CURRENT_TIMESTAMP = { toSqlString: function() { return 'CURRENT_TIMESTAMP()'; } };
var sql = mysql.format('UPDATE posts SET modified = ? WHERE id = ?', [CURRENT_TIMESTAMP, 42]);
console.log(sql); // UPDATE posts SET modified = CURRENT_TIMESTAMP() WHERE id = 42

To generate objects with a toSqlString method, the mysql.raw() method can be used. This creates an object that will be left un-touched when using in a ? placeholder, useful for using functions as dynamic values:

Caution The string provided to mysql.raw() will skip all escaping functions when used, so be careful when passing in unvalidated input.

var CURRENT_TIMESTAMP = mysql.raw('CURRENT_TIMESTAMP()');
var sql = mysql.format('UPDATE posts SET modified = ? WHERE id = ?', [CURRENT_TIMESTAMP, 42]);
console.log(sql); // UPDATE posts SET modified = CURRENT_TIMESTAMP() WHERE id = 42

If you feel the need to escape queries by yourself, you can also use the escaping function directly:

var query = "SELECT * FROM posts WHERE title=" + mysql.escape("Hello MySQL");

console.log(query); // SELECT * FROM posts WHERE title='Hello MySQL'

Escaping query identifiers

If you can't trust an SQL identifier (database / table / column name) because it is provided by a user, you should escape it with mysql.escapeId(identifier), connection.escapeId(identifier) or pool.escapeId(identifier) like this:

var sorter = 'date';
var sql    = 'SELECT * FROM posts ORDER BY ' + connection.escapeId(sorter);
connection.query(sql, function (error, results, fields) {
  if (error) throw error;
  // ...
});

It also supports adding qualified identifiers. It will escape both parts.

var sorter = 'date';
var sql    = 'SELECT * FROM posts ORDER BY ' + connection.escapeId('posts.' + sorter);
// -> SELECT * FROM posts ORDER BY `posts`.`date`

If you do not want to treat . as qualified identifiers, you can set the second argument to true in order to keep the string as a literal identifier:

var sorter = 'date.2';
var sql    = 'SELECT * FROM posts ORDER BY ' + connection.escapeId(sorter, true);
// -> SELECT * FROM posts ORDER BY `date.2`

Alternatively, you can use ?? characters as placeholders for identifiers you would like to have escaped like this:

var userId = 1;
var columns = ['username', 'email'];
var query = connection.query('SELECT ?? FROM ?? WHERE id = ?', [columns, 'users', userId], function (error, results, fields) {
  if (error) throw error;
  // ...
});

console.log(query.sql); // SELECT `username`, `email` FROM `users` WHERE id = 1

Please note that this last character sequence is experimental and syntax might change

When you pass an Object to .escape() or .query(), .escapeId() is used to avoid SQL injection in object keys.

Preparing Queries

You can use mysql.format to prepare a query with multiple insertion points, utilizing the proper escaping for ids and values. A simple example of this follows:

var sql = "SELECT * FROM ?? WHERE ?? = ?";
var inserts = ['users', 'id', userId];
sql = mysql.format(sql, inserts);

Following this you then have a valid, escaped query that you can then send to the database safely. This is useful if you are looking to prepare the query before actually sending it to the database. As mysql.format is exposed from SqlString.format you also have the option (but are not required) to pass in stringifyObject and timezone, allowing you provide a custom means of turning objects into strings, as well as a location-specific/timezone-aware Date.

Custom format

If you prefer to have another type of query escape format, there's a connection configuration option you can use to define a custom format function. You can access the connection object if you want to use the built-in .escape() or any other connection function.

Here's an example of how to implement another format:

connection.config.queryFormat = function (query, values) {
  if (!values) return query;
  return query.replace(/\:(\w+)/g, function (txt, key) {
    if (values.hasOwnProperty(key)) {
      return this.escape(values[key]);
    }
    return txt;
  }.bind(this));
};

connection.query("UPDATE posts SET title = :title", { title: "Hello MySQL" });

Getting the id of an inserted row

If you are inserting a row into a table with an auto increment primary key, you can retrieve the insert id like this:

connection.query('INSERT INTO posts SET ?', {title: 'test'}, function (error, results, fields) {
  if (error) throw error;
  console.log(results.insertId);
});

When dealing with big numbers (above JavaScript Number precision limit), you should consider enabling supportBigNumbers option to be able to read the insert id as a string, otherwise it will throw an error.

This option is also required when fetching big numbers from the database, otherwise you will get values rounded to hundreds or thousands due to the precision limit.

Getting the number of affected rows

You can get the number of affected rows from an insert, update or delete statement.

connection.query('DELETE FROM posts WHERE title = "wrong"', function (error, results, fields) {
  if (error) throw error;
  console.log('deleted ' + results.affectedRows + ' rows');
})

Getting the number of changed rows

You can get the number of changed rows from an update statement.

"changedRows" differs from "affectedRows" in that it does not count updated rows whose values were not changed.

connection.query('UPDATE posts SET ...', function (error, results, fields) {
  if (error) throw error;
  console.log('changed ' + results.changedRows + ' rows');
})

Getting the connection ID

You can get the MySQL connection ID ("thread ID") of a given connection using the threadId property.

connection.connect(function(err) {
  if (err) throw err;
  console.log('connected as id ' + connection.threadId);
});

Executing queries in parallel

The MySQL protocol is sequential, this means that you need multiple connections to execute queries in parallel. You can use a Pool to manage connections, one simple approach is to create one connection per incoming http request.

Streaming query rows

Sometimes you may want to select large quantities of rows and process each of them as they are received. This can be done like this:

var query = connection.query('SELECT * FROM posts');
query
  .on('error', function(err) {
    // Handle error, an 'end' event will be emitted after this as well
  })
  .on('fields', function(fields) {
    // the field packets for the rows to follow
  })
  .on('result', function(row) {
    // Pausing the connnection is useful if your processing involves I/O
    connection.pause();

    processRow(row, function() {
      connection.resume();
    });
  })
  .on('end', function() {
    // all rows have been received
  });

Piping results with Streams

The query object provides a convenience method .stream([options]) that wraps query events into a Readable Stream object. This stream can easily be piped downstream and provides automatic pause/resume, based on downstream congestion and the optional highWaterMark. The objectMode parameter of the stream is set to true and cannot be changed (if you need a byte stream, you will need to use a transform stream, like objstream for example).

For example, piping query results into another stream (with a max buffer of 5 objects) is simply:

connection.query('SELECT * FROM posts')
  .stream({highWaterMark: 5})
  .pipe(...);

Multiple statement queries

Support for multiple statements is disabled for security reasons (it allows for SQL injection attacks if values are not properly escaped). To use this feature you have to enable it for your connection:

var connection = mysql.createConnection({multipleStatements: true});

Once enabled, you can execute multiple statement queries like any other query:

connection.query('SELECT 1; SELECT 2', function (error, results, fields) {
  if (error) throw error;
  // `results` is an array with one element for every statement in the query:
  console.log(results[0]); // [{1: 1}]
  console.log(results[1]); // [{2: 2}]
});

Additionally you can also stream the results of multiple statement queries:

var query = connection.query('SELECT 1; SELECT 2');

query
  .on('fields', function(fields, index) {
    // the fields for the result rows that follow
  })
  .on('result', function(row, index) {
    // index refers to the statement this result belongs to (starts at 0)
  });

Joins with overlapping column names

When executing joins, you are likely to get result sets with overlapping column names.

By default, node-mysql will overwrite colliding column names in the order the columns are received from MySQL, causing some of the received values to be unavailable.

However, you can also specify that you want your columns to be nested below the table name like this:

var options = {sql: '...', nestTables: true};
connection.query(options, function (error, results, fields) {
  if (error) throw error;
  /* results will be an array like this now:
  [{
    table1: {
      fieldA: '...',
      fieldB: '...',
    },
    table2: {
      fieldA: '...',
      fieldB: '...',
    },
  }, ...]
  */
});

Or use a string separator to have your results merged.

var options = {sql: '...', nestTables: '_'};
connection.query(options, function (error, results, fields) {
  if (error) throw error;
  /* results will be an array like this now:
  [{
    table1_fieldA: '...',
    table1_fieldB: '...',
    table2_fieldA: '...',
    table2_fieldB: '...',
  }, ...]
  */
});

Transactions

Simple transaction support is available at the connection level:

connection.beginTransaction(function(err) {
  if (err) { throw err; }
  connection.query('INSERT INTO posts SET title=?', title, function (error, results, fields) {
    if (error) {
      return connection.rollback(function() {
        throw error;
      });
    }

    var log = 'Post ' + results.insertId + ' added';

    connection.query('INSERT INTO log SET data=?', log, function (error, results, fields) {
      if (error) {
        return connection.rollback(function() {
          throw error;
        });
      }
      connection.commit(function(err) {
        if (err) {
          return connection.rollback(function() {
            throw err;
          });
        }
        console.log('success!');
      });
    });
  });
});

Please note that beginTransaction(), commit() and rollback() are simply convenience functions that execute the START TRANSACTION, COMMIT, and ROLLBACK commands respectively. It is important to understand that many commands in MySQL can cause an implicit commit, as described in the MySQL documentation

Ping

A ping packet can be sent over a connection using the connection.ping method. This method will send a ping packet to the server and when the server responds, the callback will fire. If an error occurred, the callback will fire with an error argument.

connection.ping(function (err) {
  if (err) throw err;
  console.log('Server responded to ping');
})

Timeouts

Every operation takes an optional inactivity timeout option. This allows you to specify appropriate timeouts for operations. It is important to note that these timeouts are not part of the MySQL protocol, and rather timeout operations through the client. This means that when a timeout is reached, the connection it occurred on will be destroyed and no further operations can be performed.

// Kill query after 60s
connection.query({sql: 'SELECT COUNT(*) AS count FROM big_table', timeout: 60000}, function (error, results, fields) {
  if (error && error.code === 'PROTOCOL_SEQUENCE_TIMEOUT') {
    throw new Error('too long to count table rows!');
  }

  if (error) {
    throw error;
  }

  console.log(results[0].count + ' rows');
});

Error handling

var connection = require('mysql').createConnection({
  port: 84943, // WRONG PORT
});

connection.connect(function(err) {
  console.log(err.code); // 'ECONNREFUSED'
  console.log(err.fatal); // true
});

connection.query('SELECT 1', function (error, results, fields) {
  console.log(error.code); // 'ECONNREFUSED'
  console.log(error.fatal); // true
});

Normal errors however are only delegated to the callback they belong to. So in the example below, only the first callback receives an error, the second query works as expected:

connection.query('USE name_of_db_that_does_not_exist', function (error, results, fields) {
  console.log(error.code); // 'ER_BAD_DB_ERROR'
});

connection.query('SELECT 1', function (error, results, fields) {
  console.log(error); // null
  console.log(results.length); // 1
});

Last but not least: If a fatal errors occurs and there are no pending callbacks, or a normal error occurs which has no callback belonging to it, the error is emitted as an 'error' event on the connection object. This is demonstrated in the example below:

connection.on('error', function(err) {
  console.log(err.code); // 'ER_BAD_DB_ERROR'
});

connection.query('USE name_of_db_that_does_not_exist');

Note: 'error' events are special in node. If they occur without an attached listener, a stack trace is printed and your process is killed.

tl;dr: This module does not want you to deal with silent failures. You should always provide callbacks to your method calls. If you want to ignore this advice and suppress unhandled errors, you can do this:

// I am Chuck Norris:
connection.on('error', function() {});

Exception Safety

This module is exception safe. That means you can continue to use it, even if one of your callback functions throws an error which you're catching using 'uncaughtException' or a domain.

Type casting

For your convenience, this driver will cast mysql types into native JavaScript types by default. The following mappings exist:

Number

• TINYINT
• SMALLINT
• INT
• MEDIUMINT
• YEAR
• FLOAT
• DOUBLE

Date

• TIMESTAMP
• DATE
• DATETIME

Buffer

• TINYBLOB
• MEDIUMBLOB
• LONGBLOB
• BLOB
• BINARY
• VARBINARY
• BIT (last byte will be filled with 0 bits as necessary)

String

Note text in the binary character set is returned as Buffer, rather than a string.

• CHAR
• VARCHAR
• TINYTEXT
• MEDIUMTEXT
• LONGTEXT
• TEXT
• ENUM
• SET
• DECIMAL (may exceed float precision)
• BIGINT (may exceed float precision)
• TIME (could be mapped to Date, but what date would be set?)
• GEOMETRY (never used those, get in touch if you do)

It is not recommended (and may go away / change in the future) to disable type casting, but you can currently do so on either the connection:

var connection = require('mysql').createConnection({typeCast: false});

Or on the query level:

var options = {sql: '...', typeCast: false};
var query = connection.query(options, function (error, results, fields) {
  if (error) throw error;
  // ...
});

Here's an example of converting TINYINT(1) to boolean:

connection = mysql.createConnection({
  typeCast: function (field, next) {
    if (field.type === 'TINY' && field.length === 1) {
      return (field.string() === '1'); // 1 = true, 0 = false
    } else {
      return next();
    }
  }
});

WARNING: YOU MUST INVOKE the parser using one of these three field functions in your custom typeCast callback. They can only be called once.

Connection Flags

If, for any reason, you would like to change the default connection flags, you can use the connection option flags. Pass a string with a comma separated list of items to add to the default flags. If you don't want a default flag to be used prepend the flag with a minus sign. To add a flag that is not in the default list, just write the flag name, or prefix it with a plus (case insensitive).

Please note that some available flags that are not supported (e.g.: Compression), are still not allowed to be specified.

Example

The next example blacklists FOUND_ROWS flag from default connection flags.

var connection = mysql.createConnection("mysql://localhost/test?flags=-FOUND_ROWS");