How can I replace my string into mysql.format?

Question

I have a question about mysql.format.

I am trying to put my string variable into mysql.format depending on the condition in the if statement with Javascript.

For example.

var query = mysql.format(`SELECT * FROM employees WHERE ?
                          , [isAlwaystrue ? 1 : 'emp_no = 1']

But with this approach, the query does not work well.

To find out the problem, look up the query for mysql.format as shown below.

SELECT * FROM employees WHRERE 'emp_no = 1';

It looks like emp_no = 1 is surrounded by a single dot.

I'll ask for help. please

Answer 1

If you are using string literals you could change your statement to this

var query = mysql.format(`SELECT * FROM employees WHERE ?
                          , ${isAlwaystrue ? 1 : 'emp_no = 1'} 

Answer 2

You could keep the logic easy to understand and do it the long way:

var query;
if (isAlwaystrue) {
    query = mysql.format(`SELECT * FROM employees`);
} else {
    query = mysql.format(`SELECT * FROM employees WHERE emp_no = 1`);
}

Or you can try the shorter way, but make the code more confusing:

mysql.format(`SELECT * FROM employees WHERE ${isAlwaystrue ? 1 : 'emp_no = 1'}`);