I´m trying to get the result of my query which is running in my function.
But my result is undefined. What i´m doing wrong?
function:
function sqllis(sql_q) {
sql.connect(dbConfig, function (err) {
if (err) console.log(err);
var request = new sql.Request();
request.query(sql_q, function (err, recordset) {
return recordset.recordsets;
});
});
}
My try to get the result:
var result = sqllis("select * from dbo.sys_user ");
console.log(result);
The sql.query function uses a callback meaning it is asynchronous code. You cannot resolve the result synchronously. I am not sure whether you are using the sql or mssql npm library, but I'd suggest looking if there is a native promise approach or to wrap your code into a promise oriented approach. If you're using the mssql library, when omitting the callback, it returns automatically a promise and you can use it like this.
function sqllis(sql_q) {
sql.connect(dbConfig, function (err) {
if (err) console.log(err);
var request = new sql.Request();
return request.query(sql_q);
});
}
and use it asynchronously like this:
sqllis("select * from dbo.sys_user ")
.then(function(results){ console.log(results) })
.catch(function(err){ console.log(err) });
You can also pass a callback function.
function sqllis(sql_q, callback) {
sql.connect(dbConfig, function (err) {
if (err) console.log(err);
var request = new sql.Request();
request.query(sql_q, callback);
});
}
and use it like this
sqllis("select * from dbo.sys_user ", function(err, results){
console.log(err);
console.log(results); //results.recordsets
})
You will have to use a callback to return results from an async function.
function sqllis(sql_q, callback) {
sql.connect(dbConfig, function (err) {
if (err) console.log(err);
var request = new sql.Request();
request.query(sql_q, function (err, recordset) {
callback(err, recordset); // USING CALLBACK
});
});
}
var result = sqllis("select * from dbo.sys_user ", (err,res) => {
console.log(res);
})
Reference articles you could go through:
