How to update a table from a JSON object where the conditions are in a JSON object? - node.js

Question

I want to update a taable from a JSON object. The WHERE clause of the update has more than one columns. I tried this :
connexion.query("update my_table set ? where ?", [{ "param_valeur": emails }, { "param_key": "paramKey", "flotte_id": 1 }], function (err, rows) {
console.log("=================== sql =", this.sql);
if (err)
throw err;
res.send("");
});
but at runtime the WHERE clause does not have the AND keyword ! So how to fix that ?

Answer 1

OK, you want to use dynamic data by sending a json to MySQL WHERE query, from what I found out until now this is not a trivial operation... So, my first answer is not a good solution for your requirements so I write a new and dynamic code. (a little bit more complicated than the first answer...)
Please try the solution and let my know if this is what you want.
my answer is based on https://www.npmjs.com/package/mysql#preparing-queries, you can read this docs section for better understanding of the double question marks syntax.
let paramsSETObj = { "param_valeur": emails };
let paramsWHEREObj = { "param_key": "paramKey", "flotte_id": 1 };
// separate the question marks with comma ', '
let questionMarksForSET = this.getQuestionMarksStr(Object.keys(paramsSETObj).length, ', ');
let valuesForSETArray = this.convertObjectToArray(paramsSETObj);
// separate the question marks with 'AND'
let questionMarksForWHERE = this.getQuestionMarksStr(Object.keys(paramsWHEREObj).length, ' AND ');
let valuesForWHEREArray = this.convertObjectToArray(paramsWHEREObj);
let sql = `UPDATE my_table SET ${questionMarksForSET} WHERE ${questionMarksForWHERE}`;
let inserts = [...valuesForSETArray, ...valuesForWHEREArray];
sql = mysql.format(sql, inserts);
connexion.query(sql, function (err, rows) {
if (err)
throw err;
res.send("");
});
// Convert an object to array, where each key is before the value
module.exports.convertObjectToArray = function (obj) {
let arr = [];
for (let key in obj) {
arr.push(key);
arr.push(obj[key]);
}
return arr;
}
/**
* Get a question marks string separate each pair with the equal sign '='
* the amount of the questions marks pairs is the same as the keys of the object from the request.
* The separator in this case is comma ',' or 'AND' - this is a must for your requirement in the question.
* example:
* questionMarksForSET: ?? = ? , ?? = ?
* questionMarksForWHERE: ?? = ? AND ?? = ?
*/
module.exports.getQuestionMarksStr = function (objKeysLength, separator) {
let questionsMarks = '';
for (let i = 0; i < objKeysLength; i++) {
// if the index is not in the last object key - add the separator else add empty string
let commaOrAndSeparator = (i !== objKeysLength - 1) ? separator : '';
questionsMarks += ' ?? = ? ' + commaOrAndSeparator;
}
return questionsMarks;
}

Answer 2

Try this:
connexion.query('UPDATE my_table SET param_valeur = ? WHERE param_key = ? AND flotte_id = ?', [emails, "paramKey", 1], function (err, rows) {
if (err)
throw err;
res.send("");
});