enhancer-data-bridge/database-proxy/mysql.js

A bridge between Enhancer Clould and user business datasource

var mysql = require('mysql');

var dbTypeMap = {
    '1': 'TINYINT',
    '2': 'SMALLINT',
    '3': 'INT',
    '4': 'FLOAT',
    '5': 'DOUBLE',
    '7': 'TIMESTAMP',
    '8': 'BIGINT',
    '9': 'MEDIUMINT',
    '10': 'DATE',
    '11': 'TIME',
    '12': 'DATETIME',
    '13': 'YEAR',
    '16': 'BIT',
    '252': 'BLOB',
    '253': 'VARCHAR',
    '254': 'CHAR',
    '246': 'DECIMAL'
};

var varTypeMap = {
    '1': 'number', 
    '2': 'number', 
    '3': 'number', 
    '4': 'number',
    '5': 'number',
    '7': 'number',
    '8': 'number',
    '9': 'string',
    '10': 'string',
    '11': 'string',
    '12': 'string',
    '13': 'string',
    '14': 'string',
    '15': 'string',
    '16': 'string',
    '252': 'string',
    '253': 'string',
    '254': 'string',
    '246': 'number'
};

module.exports = {
    testConnection: function(dbConfig, cb) {
        var conn = mysql.createConnection(dbConfig);
        conn.query('SELECT 1', function(err, result) {
            err ? cb(null, err.message) : cb(null, true);
            conn.destroy();
        });
    },
    testSql: function(dbConfig, sql, params, cb) {
        // mysql
        var conn = mysql.createConnection(dbConfig);

        // limit
        sql = sql.replace(/\sLIMIT\s+(\d+|\?)\s*(\,\s*(\d+|\?)\s*)?$/i, '').trim();
        var isSelect = /^SELECT(\s|\()/i.test(sql);
        var isWithAs = /WITH(\s|\()/i.test(sql);
        if (isSelect || isWithAs) {
            sql = sql + ' LIMIT 0, 1';
        }
        conn.query(sql, params, function(err, result, fields) {
            if (err) {
                cb(null, {
                    success: false,
                    message: err.message
                });
                return conn.destroy();
            }
            fields = ((isSelect || isWithAs) ? fields : (fields[fields.length - 2]) || fields[0]) || [];
            cb(null, {
                success: true,
                metaData: fields && fields.length ? fields.map(function(f) {
                    f.dbType = dbTypeMap[f.type];
                    f.varType = varTypeMap[f.type] || 'string';
                    return f;
                }) : []
            });
            conn.destroy();
        });
    }, 
    getTableNames: function(dbConfig, cb) {
        var conn = mysql.createConnection(dbConfig);
        conn.query('SHOW TABLES', [], function(err, results) {
            if ( err ) {
                cb(err);
                return conn.destroy();
            }
            var tableNames = [];
            for (var i in results) {
                tableNames.push(results[i]['Tables_in_' + dbConfig.database]);
            }
            cb(null, tableNames);
            conn.destroy();
        });
    },
    getTableColumns: function(dbConfig, tabName, cb) {
        var conn = mysql.createConnection(dbConfig);
        conn.query('SHOW COLUMNS FROM ' +  tabName, [], function(err, columns) {
            if ( err ) {
                cb(err);
                return conn.destroy();
            }

            columns = columns.map(function(col) {
                col.name = col.Field;
                col.dbType = col.Type;
                return col;
            });
            cb(null, columns);
            conn.destroy();
        });
    }
}