Nodejs invalid input syntax for integer error - node.js

Question

I using postgres sql, nodejs, express
app.get("/topic/create", function(req, res) {
var sql = "SELECT id, title FROM topic";
client.query(sql, function(err, res2) {
console.log(res2.rows);
//res.render("create", { topics: res2.rows });
});
});
this code is my router code
but when i enter that url it was error
error: invalid input syntax for integer: "create"
name: 'error',
length: 110,
severity: 'ERROR',
code: '22P02', line: '62',routine: 'pg_atoi'
i dont know reason because sql was working on other url only that app.get code doesn't working
//라우팅 작업
app.get("/", function(req, res) {
res.redirect("/topic");
});
app.get("/topic", function(req, res) {
var sql = "SELECT id, title FROM topic";
client.query(sql, function(err, res2) {
if (err) {
console.log(err);
} else {
res.render("view", { topics: res2.rows });
}
});
});
app.get("/topic/:id", function(req, res) {
var id = req.params.id;
var sql1 = "SELECT id, title FROM topic";
var sql2 = "SELECT * FROM topic where id=$1";
client.query(sql2, [id], function(err, res2) {
if (err) {
console.log(err);
} else {
client.query(sql1, function(err, res3) {
if (err) {
console.log(err);
res.status(500).send("Internal Server Error");
} else {
var list = [];
var result = res3.rows;
for (var i = 0; i < result.length; i++) {
list.push(res3.rows[i]);
}
res.render("view", { details: res2.rows, topics: list });
}
});
}
});
});
this is my router code it was same. this code is good working
i dont know why only that url make error

Answer 1

app.get("/topic/create", function(req, res) {
var sql = "SELECT id, title FROM topic";
client.query(sql, function(err, res2) {
console.log(res2.rows);
//res.render("create", { topics: res2.rows });
});
});
You have to put this router first then below one,
app.get("/topic/:id", function(req, res) {
var id = req.params.id;
var sql1 = "SELECT id, title FROM topic";
var sql2 = "SELECT * FROM topic where id=$1";
client.query(sql2, [id], function(err, res2) {
if (err) {
console.log(err);
} else {
client.query(sql1, function(err, res3) {
if (err) {
console.log(err);
res.status(500).send("Internal Server Error");
} else {
var list = [];
var result = res3.rows;
for (var i = 0; i < result.length; i++) {
list.push(res3.rows[i]);
}
res.render("view", { details: res2.rows, topics: list });
}
});
}
});
});
this will work, Because express take and match with first one. It get failed, That's why you got this error.

Answer 2

as #tadman mentioned, you need to define app.get("/topic/create function before the app.get("/topic/:id" function. otherwise, express thinks that you are executing app.get("/topic/:id" and the id is create.
Hope this helps.