使用node操作mysql数据库实例介绍

var connection = mysql.createConnection('mysql://user:pass@host/db?debug=true&charset=BIG5_CHINESE_CI&timezone=-0700');

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

// create var poolCluster = mysql.createPoolCluster(); poolCluster.add(config); // anonymous group poolCluster.add('MASTER', masterConfig); poolCluster.add('SLAVE1', slave1Config); poolCluster.add('SLAVE2', slave2Config); // 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 }); poolCluster.getConnection('SLAVE*', 'ORDER', 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) {}); // destroy poolCluster.end();

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

var db_config = { host: 'localhost', user: 'root', password: '', database: 'example' }; var connection; function handleDisconnect() { connection = mysql.createConnection(db_config); // Recreate the connection, since // the old one cannot be reused. connection.connect(function(err) { // The server is either down if(err) { // or restarting (takes a while sometimes). console.log('error when connecting to db:', err); setTimeout(handleDisconnect, 2000); // We introduce a delay before attempting to reconnect, } // to avoid a hot loop, and to allow our node script to }); // process asynchronous requests in the meantime. // If you're also serving http, display a 503 error. connection.on('error', function(err) { console.log('db error', err); if(err.code === 'PROTOCOL_CONNECTION_LOST') { // Connection to the MySQL server is usually handleDisconnect(); // lost due to either server restart, or a } else { // connnection idle timeout (the wait_timeout throw err; // server variable configures this) } }); } handleDisconnect();

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

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

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

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

var sorter = 'date'; var query = 'SELECT * FROM posts ORDER BY ' + mysql.escapeId(sorter); console.log(query); // SELECT * FROM posts ORDER BY `date`

var sorter = 'date'; var query = 'SELECT * FROM posts ORDER BY ' + mysql.escapeId('posts.' + sorter); console.log(query); // SELECT * FROM posts ORDER BY `posts`.`date`

var userId = 1; var columns = ['username', 'email']; var query = connection.query('SELECT ?? FROM ?? WHERE id = ?', [columns, 'users', userId], function(err, results) { // ... }); console.log(query.sql); // SELECT `username`, `email` FROM `users` WHERE id = 1

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

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" });

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

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 });

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

connection.query('SELECT 1; SELECT 2', function(err, results) { if (err) throw err; // `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}] });

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) });

connection.beginTransaction(function(err) { if (err) { throw err; } connection.query('INSERT INTO posts SET title=?', title, function(err, result) { if (err) { connection.rollback(function() { throw err; }); } var log = 'Post ' + result.insertId + ' added'; connection.query('INSERT INTO log SET data=?', log, function(err, result) { if (err) { connection.rollback(function() { throw err; }); } connection.commit(function(err) { if (err) { connection.rollback(function() { throw err; }); } console.log('success!'); }); }); }); });

err.code = string err.fatal => boolean