"update" query - error invalid input synatx for integer: "{39}" - postgresql - sql

Question

I'm using node js 0.10.12 to perform querys to postgreSQL 9.1.
I get the error error invalid input synatx for integer: "{39}" (39 is an example number) when I try to perform an update query
I cannot see what is going wrong. Any advise?
Here is my code (snippets) in the front-end
//this is global
var gid=0;
//set websockets to search - works fine
var sd = new WebSocket("ws://localhost:0000");
sd.onmessage = function (evt)
{
//get data, parse it, because there is more than one vars, pass id to gid
var received_msg = evt.data;
var packet = JSON.parse(received_msg);
var tid = packet['tid'];
gid=tid;
}
//when user clicks button, set websockets to send id and other data, to perform update query
var sa = new WebSocket("ws://localhost:0000");
sa.onopen = function(){
sa.send(JSON.stringify({
command:'typesave',
indi:gid,
name:document.getElementById("typename").value,
}));
sa.onmessage = function (evt) {
alert("Saved");
sa.close;
gid=0;//make gid 0 again, for re-use
}
And the back -end (query)
var query=client.query("UPDATE type SET t_name=$1,t_color=$2 WHERE t_id = $3 ",[name, color, indi])
query.on("row", function (row, result) {
result.addRow(row);
});
query.on("end", function (result) {
connection.send("o");
client.end();
});
Why this not work and the number does not get recognized?
Thanks in advance

Answer 1

As one would expect from the initial problem, your database driver is sending in an integer array of one member into a field for an integer. PostgreSQL rightly rejects the data and return an error. '{39}' in PostgreSQL terms is exactly equivalent to ARRAY[39] using an array constructor and [39] in JSON.
Now, obviously you can just change your query call to pull the first item out of the JSON array. and send that instead of the whole array, but I would be worried about what happens if things change and you get multiple values. You may want to look at separating that logic out for this data structure.