code: function mkInsert(table, obj) {
    const ks = Object.keys(obj).map(x => `\`${x}\``);
    const vs = Object.values(obj).map(toMysqlObj);
  
    return `INSERT INTO \`${table}\`(${ks}) VALUES(${vs})`;
  }
docs: INSERT is the simplest operation, because there is no WHERE part in it.
  @param {Object} obj - Object like { name: "Abc", age: 15 }.
  @returns {string} - e.g. "INSERT INTO X(name, age) VALUES('Abc', 15)"