How to use

authenticate

function

in

Sequelize

connection
 .authenticate()
 .then(() => {
  console.info('INFO - Database connected.')
 })
 .catch(err => {
  console.error('ERROR - Unable to connect to the database:', err)
 })

/**
 * Tests the connection to the DB, returning true if the connection succeeds. If the connection
 * fails, an error is thrown.
 */
function testConnection() {
 return db.authenticate()
  .then(() => true);
}

var callbackDatabaseCreation = function() { 
    sequelizeMaster.close();
    sequelize.authenticate()
      .then(function(err) {
       scriptExecuter(scriptTablesCreation, callbackCreation, sequelize)
      });  
 }

sequelize
.authenticate()
.then(function(err) {
 console.log('Connection has been established successfully.');
}, function (err) {
 console.log('Unable to connect to the database:', err);
});

sequelizeConnection.authenticate().then(() => {
  console.log('Connection has been established successfully!');
}).catch((err) => {
  console.log('Can\'t establish database connection:\n' + err);
});

// Try DB connection
sequelize
 .authenticate()
 .then(() => {
  logger.info('MySQL connection has been established successfully.')
 })
 .catch(err => {
  logger.error('Unable to connect to the database:', err)
  process.exit(2)
 })

db
 .authenticate()
 .then(() => {
  console.log('Connection has been established successfully.')
 })
 .catch(err => {
  console.error('Unable to connect to the database:', err)
 })

connection
 .authenticate()
 .then(() => {
  console.info('INFO - Database connected.')
 })
 .catch(err => {
  console.error('ERROR - Unable to connect to the database:', err)
 })

connection
 .authenticate()
 .then(() => {
  console.info('INFO - Database connected.')
 })
 .catch(err => {
  console.error('ERROR - Unable to connect to the database:', err)
 })

// establish mysql connection
sequelize
 .authenticate()
 .then(() => {
  logger.info('Sequelize has established mysql connection successfully.');
 })
 .catch(err => {
  logger.error('Sequelize was unable to connect to the database:', err);
 });

// Verify connection successfull
sequelize
 .authenticate()
 .then(function(err) {
  console.log('DB connection has been established successfully.');
 }, function (err) {
  console.log('Unable to connect to the database:', err);
 });

sequelize
 .authenticate()
 .then(() => {
  logger.info('Successfully established connection to database')
 })
 .catch((err) => {
  logger.error('Unable to connect to database', err)
 })

//测试数据库链接
sequelize.authenticate().then(function () {
  console.log("数据库连接成功");
}).catch(function (err) {
  //数据库连接失败时打印输出
  console.error(err);
  throw err;
});

var callbackDatabaseCreationBig = function() { 
    sequelizeMaster.close();
    sequelizeDWH.authenticate()
      .then(function(err) {
       scriptExecuter(scriptTablesCreationBig, callbackCreationBig, sequelizeDWH)
      });  
 }

sequelize.authenticate()
 .then(() => {
  console.log("Conectado")
 })
 .catch(err => {
  console.log("No conectado")
 })