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Automatically stringifying object when inserting to a MySQL JSON column with knex

Let's jump straight to an example code:
create table test_json_table
(
data json not null
);
I can insert to the table like this:
const columns = { data: "{ some_json: 123 }" }; // notice that the data column is passed as string
await knex('test_json_table').insert(columns);
And get data from the table like this:
await knex('test_json_table').select();
// returns:
// [
// { data: { some_json: 123 } } // notice that the data is returned as parsed JavaScript object (not a string)
// ]
When inserting a row the JSON column needs to be passed as a serialised string. When retrieving the row, an already parsed object is returned.
This is creating quite a mess in the project. We are using TypeScript and would like to have the same type for inserts as for selects, but this makes it impossible. It'd be fine to either always have string or always object.
I found this topic being discussed at other places, so it looks like I am not alone in this (link, link). It seems like there is no way to convert the object to string automatically. Or I am missing something?
It'd be nice if knex provided a hook where we could manually serialise the object into string when inserting.
What would be the easiest way to achieve that? Is there any lightweight ORM with support for that? Or any other option?

You could try objection.js that allows you to declare certain columns to be marked as json attributes and those should be stringified automatically when inserting / updating their values https://vincit.github.io/objection.js/api/model/static-properties.html#static-jsonattributes
I haven't tried if it works with mysql though. I don't see any reason why it wouldn't.

I think the easiest way using jsonb data type. mysql json type
We prefer postgresql for this kind of problem at office, easier and solid database for your problem.

Well you could call your own function before inserting that converts all objects to string and call it every time before you insert.
You can probably wrap knex to do it automatically as well.

supplying initialization json string as parameter to jquery method

i have just begun using jquery datatables in my project and I do like it so far. I have many tables, sometimes 2-3 on a page. Rather than have to keep track of what initialization string I am using for a specific table and trying to remember what webpage its on, I have built an xml file to store all the initialization strings. I built some jquery functions to retrieve the strings on document ready but it never dawned on me how to actually inject the json into the method as a parameter.
If i was doing it manually you would call
selector.dataTables(json initializer string here);
Once I have that string how do I actually inject it into the method call? Or do I have to create that whole code line and inject it into my script?

If the json data comes in as something like this:
{"order": [[ 3, "desc" ]]}
You could use jquery to get the JSON via a HTTP GET request.
$.getJSON('somejson.json',function(data){
someSelector.dataTables(data)
});
Because you are using getJSON it will expect the JSON to be in that format and do the parsing for you.
Or if the JSON is available already(since you are using jquery you can use it to parse the JSON data just in case there may be a browser support issue since IE7 and below does not support JSON.parse.):
var options = $.parseJSON(someData);
someSelector.dataTables(options)

you can assign the json string to a variable...
var tableSettings = theJsonString;
selector.dataTables(tableSettings);
you may need to convert the string to an object first...
//javascript
var tableSettings = JSON.parse(theJsonString);
//jquery
var tableSettings = $.parseJSON(theJsonString);

Populate Javascript Object With Data Returned From Program Call

I have a javascript function that calls an external program and I need to put the result into an object, which will contain multiple rows with multiple values for each, example below:
$.get(programcall , function(data) {
var dealers = {};
data = {0:{'name':'name1','address':'address1','phone':'phone1','miles':1.2},1:{'name':'name2','address':'address2','phone':'phone2','miles':2.2}};
dealers = data;
});
This test works because "data" is not enclosed in quotes, however when the content of "data" is returned from the called program, it just becomes text content in "dealers".
How can I get the value stored as an object?
The called program is MINE, so I can change the format if necessary to make it work.
The data will be a list of customers with name, address etc, which I want to process using javascript and to populate a DIV.

If the string is valid JSON, use the native JSON.parse function to turn it into an object.
For example:
data = JSON.parse('{"mything": 3}')
One thing to look out for: JSON needs double quotes around key names, so {"mything": 3} works but {'mything': 3} will not validate.

Your external server call is returning string content as the data object. This is, hopefully, a valid JSON format but it is still just a string.
What you probably want to do is use jQuery's getJSON function instead of a simple $.get, since it will take care of converting the response to a JSON object similar to your example.
$.getJSON(programcall, function(data) {
// data is now a JSON object not a string, if it's valid json from your server response

Passing hashmap from javascript to servlet

I created a simplehashmap using the accepted solution in this question:
How to create a simple map using JavaScript/JQuery
I however need to send this var to a servlet and retrieve them onto a Java HashMap. How do I do that.
The key is a string while the value is an array, say like:
`[1,'apple,orange, banana'],[2,'apple,peach, banana']` ...
I need the keys 1,2 and the array loaded onto a Java HashMap.
I tried to post it using jquery. where selectedrows is my map
$.post(url, { id: selectedrows });

I creates a JSON string and then sent it via an ajax post to the servlet and build the HashMap there.

How do I remove the square brackets at the end of a JS variable name during AJAX calls?

I currently have the following javascript array:
var stuffs = ['a', 'b'];
I pass the above to the server code using jQuery's load:
var data = {
'stuffs': stuffs
};
$(".output").load("/my-server-code/", data, function() {
});
On the server side, if I print the content of request.POST(I'm currently using Django), I get:
'stuffs[]': [u'a', u'b']
Notice the [] at the prefix of the variable name stuffs. Is there a way to remove that [] before it reaches the server code?

This is default behavior in jQuery 1.4+...if you want the post to be &stuffs=a&stuffs=b instead of &stuffs[]=a&stuffs[]=b you should set the traditional option to true, like this:
$.ajaxSetup({traditional: true});
Note this affects all requests... which is usually what you want in this case. If you want it to be per-request you should use the longer $.ajax() call and set traditional: true there. You can find more info about traditional in the $.param() documentation.

When an array is submitted using a GET request, through a form or AJAX, each element is given the name of the array, followed by a pair of optionally empty square brackets. So the jQuery is generating the url http://example.com/get.php?stuff[]=a&stuff[]=b. This is the only way of submitting an array, and the javascript is following the standard.
POST requests work in exactly the same way (unless the json is sent as one long json string).
In PHP, this is parsed back into the original array, so although the query string can be a little strange, the data is recieved as it was sent. $_GET['stuff'][0] works correctly in PHP.
I'm not sure how Django parses query strings.

The [] indicates that the variable is an array. I imagine that the appending of the [] to your variable name is Python/Django's way of telling you it is an array. You could probably implement your own print function which does not show them.