Is there a JS library that supports writing linq to sql queries with nodejs?

Question

I see jslinq, and see tds js libraries for using node and SQL together... So has anyone ever used those technologies together?

I want to be able to write linq to sql queries in a nodejs app...

Answer 1

I've started with JS variant of LINQ to Entities this week. Check UniMapperJS

Example

var comments = await Comment.getAll()
.where(e => e.author.endsWith("something") || e.author.startsWith("somethingElse"))
.orderByDescending("created")
.limit(10)
.skip(0)
.exec();

But cuz of limitation of JS, it was hard to figure out, how to accept variables in where because that arrow functions are parsed as string. I've solved it by "virtual" variable ($) and list of args as last param.

var comments = await Comment.getAll()
.where(e => e.author.endsWith($) || e.author.startsWith($), filter.endsWith, filter.name)
.orderByDescending("created")
.limit(10)
.skip(0)
.select(e => e.author)
.exec();

Answer 2

Today, JayData http://jaydata.org/ do it.

You can use the new ES6 Arrow Function syntax that looks very similar to C# (with a browser that supports it, like lastest Firefox, or a transpiler, like TypeScript or Traceur):

todoDB.Todos
    .filter(todo => todo.Completed == true)
    .map(todo => todo.Task )
    .forEach(taskName => $('#list')
    .append('Task: ' + taskName + ' completed'));

The query will be converted to a SQL Query (select Task from Todos where Completed = true) or a $filter URL parameter (http://.../?$filter=Completed%20eq%201&$select=Task), depending of the data source...

Answer 3

You should checkout the edge.js framework, it connects node.js with .Net. One way would be to use the built in T-SQL support in edge, and then use something like linq.js to manipulate the results.

var getTop10Products = edge.func('sql', function () {/*
    select top 10 * from Products 
*/});

getTop10Product(null, function (error, products) {
    if (error) throw error;
    console.log(products);
});

Otherwise, you could setup an EF datacontext in a .Net library and call out to that using Linq

var getTop10Product = edge.func(function () {/*
    async (input) => { 
      using (var db = new ProductContext())
      {
        //Linq to EF query
        var query = from b in db.Products
                    orderby b.Name
                    select b;
        return query.Take(10).ToList();
      }
    }
*/});