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

A bridge between Enhancer Clould and user business datasource

var dmdb = require('dmdb');
var logger = require('log4js').getLogger('io');

var dbTypeMap = {
};

var varTypeMap = {
};

module.exports = {
    testConnection: function(dbConfig, cb) {
        dmdb.createPool({
            connectString: `dm://${dbConfig.user}:${dbConfig.password}@${dbConfig.host}:${dbConfig.port}?injectArray=true`,
            poolMin: 1,
            poolMax: 1
        }).then(function(pool) {
            pool.getConnection(function(err, conn) {
                if (err) {
                    cb(err);
                    return
                }
                conn.execute('SELECT 1 FROM DUAL', [], function(err, result) {
                    if (err) {
                        cb(err);
                        return
                    }
                    cb(null, true);
                    conn.close();
                    pool.close();
                });
            });
        }).catch(function(err) {
            cb(err);
        });
    },
    testSql: function(dbConfig, sql, params, cb) {
        // limit
        sql = sql.replace(/\sLIMIT\s+(\d+|\?)\s*(\,\s*(\d+|\?)\s*)?$/i, '').trim();
        var isSelect = /^SELECT(\s|\()/i.test(sql);
        if (isSelect) {
            sql = sql + ' LIMIT 0, 1';
        }
        params = params.map(function(val) {
            if (val === 0) {
                return null;
            }
            return val;
        });
        logger.debug('TEST SQL:\n', sql);
        logger.debug('PARAMS:\n', params);
        dmdb.createPool({
            connectString: `dm://${dbConfig.user}:${dbConfig.password}\@${dbConfig.host}:${dbConfig.port}`,
            poolMin: 1,
            poolMax: 1
        }).then(function(pool) {
            pool.getConnection(function(err, conn) {
                if (err) {
                    cb(err);
                    return
                }
                console.log(sql);
                console.log(params);
                conn.execute(sql, params, function(err, result) {
                    if (err) {
                        cb(err);
                        return
                    }
                    // for sql procure
                    if (result.implicitResults && result.implicitResults.length) {
                        var last = result.implicitResults.length - 1;
                        result.rows = result.implicitResults[last];
                        result.metaData = result.metaData[last];
                    }
                    cb(null, {
                        success: true,
                        metaData: result.metaData.map(function(r) {
                            r.dbType = 'VARCHAR';
                            r.varType = 'string';
                            return r;
                        })
                    });
                    conn.close();
                    pool.close();
                });
            });
        }).catch(function(err) {
            cb(err);
        });
    }, 
    getTableNames: function(dbConfig, cb) {
        dmdb.createPool({
            connectString: `dm://${dbConfig.user}:${dbConfig.password}@${dbConfig.host}:${dbConfig.port}`,
            poolMin: 1,
            poolMax: 1
        }).then(function(pool) {
            pool.getConnection(function(err, conn) {
                if (err) {
                    cb(err);
                    return
                }
                conn.execute('SELECT TABLE_NAME FROM USER_TABLES', [], function(err, result) {
                    if (err) {
                        cb(err);
                        return
                    }
                    cb(null, result.rows.map(function(a) {
                        return a[0];
                    }));
                    conn.close();
                    pool.close();
                });
            });
        }).catch(function(err) {
            cb(err);
        });
    },
    getTableColumns: function(dbConfig, tabName, cb) {
        dmdb.createPool({
            connectString: `dm://${dbConfig.user}:${dbConfig.password}\@${dbConfig.host}:${dbConfig.port}`,
            poolMin: 1,
            poolMax: 1
        }).then(function(pool) {
            pool.getConnection(function(err, conn) {
                if (err) {
                    cb(err);
                    return
                }
                conn.execute('SELECT COLUMN_NAME, DATA_TYPE FROM USER_TAB_COLUMNS WHERE TABLE_NAME = ?', [tabName], function(err, result) {
                    if (err) {
                        cb(err);
                        return
                    }
                    console.log(result);
                    cb(null, result.rows.map(function(a) {
                        return {
                            name: a[0],
                            dbType: a[1]
                        }
                    }));
                    conn.close();
                    pool.close();
                });
            });
        }).catch(function(err) {
            cb(err);
        });
    }
}