如何在node.js中的mysql包中设置IF条件

Question

I'm using mysql package for node.js

Studying the documentation did not help me with my question. I want to make following:

if (SELECT table_field WHERE id = some_value ){
  // execute some code
} else{
  // execute some code
}

So I want SELECT to return either TRUE or FALSE (like EXISTS operator)

How can I do so with node.js ?

Answer 1

After you setup your connection, you'll want to do something like this:

con.connect(function(err) {
  if (err) throw err;
  console.log("Connected!");
  var sql = "SELECT table_field WHERE id = some_value" // setup your query
  con.query(sql, function (err, result) {  // pass your query
    if (err) throw err;
    console.log("Result: " + result);
    if (result) {
      // true logic
    }
    else
    {
      // false logic
    }
  });
});

You can't use the SQL query directly in the IF statement. You need to retrieve the results and then use the results as the boolean value.