node.js-从mysql查询中调用javascript变量

Question

I am trying to call javascript variables from within the mySQL query. The lines are executed with node.js environment, using syntax [node (filename)]. I understand that I could potentially do this query in 2 steps, by first query the value of min_value, and then query the max_value.

Can the request be executed in one mySQL query?

Preferably I would like to keep the code structure with vanilla js and mySQL, without adding node.js-specific commands, nor needing to load extra packages.

Javascript variables:

let min_value = 100;
let max_value = 300;

This works:

sql = `
 SELECT
   acronym,
   salaries
 FROM 
   employees
 WHERE
   salaries BETWEEN 100 and 300
ORDER BY acronym;
`;

This does not works:

sql = `
 SELECT
   acronym,
   salaries
 FROM 
   employees
 WHERE
   salaries BETWEEN ($min_value) and ($max_value)
ORDER BY acronym;
`;

Answer 1

Try using Template Literals , with the ${variable} placeholder syntax:

 let min_value = 100; let max_value = 300; let sql1 = ` SELECT acronym, salaries FROM employees WHERE salaries BETWEEN (${min_value}) and (${max_value}) ORDER BY acronym; `; let sql2 = ` SELECT acronym, salaries FROM employees WHERE salaries BETWEEN ${min_value} and ${max_value} ORDER BY acronym; `; console.log(sql1); console.log(sql2);