Why won't Express.js variable route work? - mysql

Question

So I have the code, that calls to mySQL based on the route, however it does not work...
app.get("/attitude-chart/:att", function(req, res) {
connection.query("SELECT * FROM actors ORDER BY id WHERE ?",{'attitude':`${req.params.att}`}, function(err, result) {
var html = "<h1>Attitude-chart</h1>";
html += "<ul>";
for (var i = 0; i < result.length; i++) {
html += "<li><p> ID: " + result[i].id + "</p>";
html += "<p>Name: " + result[i].name + " </p></li>";
}
html += "</ul>";
res.send(html);
});
});
results are undefined....

Answer 1

It's not clear what package you're using for MySQL, but it looks to me like your SQL is not well formed.
I would expect your query to look something like this:
connection.query('SELECT * FROM actors WHERE attitude=?', req.params.att, ...)
This will result in an SQL query that looks like:
SELECT * FROM actores WHERE attitude='your value';
In your query, you have no WHERE expression, just a placeholder where an expression should be. I'm not familiar with every MySQL package out there, but every one I know of will require you to spell out what condition you're trying to match.

Answer 2

I fixed it. Swapping WHERE and ORDER BY did the trick!
connection.query("SELECT * FROM actors WHERE ? ORDER BY id",[{'attitude':`${x}`}], function(err, result) {
console.log(result);
var html = "<h1>Attitude-chart</h1>";
html += "<ul>";
for (var i = 0; i < result.length; i++) {
html += "<li><p> ID: " + result[i].id + "</p>";
html += "<p>Name: " + result[i].name + " </p></li>";
}
html += "</ul>";
res.send(html);
});

Answer 3

You don't use a placeholder for the entire comparison expression. And the ORDER BY clause has to be after the WHERE clause.
You need to write:
connection.query("SELECT * FROM actors WHERE attitude = :attitude ORDER BY id ",{'attitude': `${req.params.att}`}, function(err, result) {
The :attitude placeholder is replaced with the value of the attitude property of the object.
And if the column is numeric, you shouldn't put req.params.att in a template literal. You should pass the numeric value to the query.