node-red insert mysql func

let table = env.get('table');
let add   = env.get('add');

if (table && msg.payload) {
    if (typeof msg.payload === 'string') {
        msg.payload = JSON.parse(msg.payload);
    }

    if (typeof msg.payload === 'object') {
        // support value
        if (typeof add === 'object') {
            msg.payload = Object.assign({}, msg.payload, add);
        }
        
        // https://reedbarger.com/how-to-transform-javascript-objects-the-power-of-objectkeys-values-entries/
        let col = Object.keys(msg.payload).map((key) => '`'+key+'`').join(',');
        let val = Object.keys(msg.payload).map((key) => ':'+key).join(',');
        
        // msg.topic = 'INSERT INTO '+table+' ('+col+') VALUES ('+val+')';
        msg.topic = `INSERT INTO \`${table}\` (${col}) VALUES (${val})`;
        
        return msg;
    }
}