I am Using Json to represent data at client side(javascript), I converted .net datatable object to json and now need to apply filter on Json data. I used _.where to apply basic data filter , but need complex filtering like:
where = (stundentID = 55 and school='abc') AND (City='xyz' or City ='abc')
Its a basic type of filtration that we used in Oracle or sql server queries. Now how can i apply such mechanism using underscore.js or some thing equivelant on Json or javascript structures. I might also need to do query of getting Top N record , using aggregation [ Sum(sales)==500] at javascript. Waiting for your valuable suggestions.
Thanks,
Assuming you have this JSON represented as a regular JavaScript object—there's no such thing as a JSON object, after all—you're best bet would likely be to use linq.js
You'd be able to do things like:
var studentFilteredArray =
Enumerable.From(students)
.Where(function(s) { return s.studenId == 55; })
.OrderBy(function(s) { return s.LastName; })
.ToArray();
Or from your example above:
.Where(function(s) {
return s.studentID === 55 && s.school === 'abc' && (s.City === 'xyz' || s.City === 'abc')
});
You also can try alasql.js , where you can use standard SQL SELECT WHERE statement. Alasql was specially designed to work with JSON arrays like tables in database.
// Create database and describe the table
var db = new alasql.Database();
db.exec('CREATE TABLE students ([studentID] INT, school STRING, [City] STRING)');
// Assign you array here
db.tables.students.data = [
{studentID: 55, school: 'abc', City:'abc'},
{studentID: 56, school: 'klm', City:'xyz'},
{studentID: 57, school: 'nyz', City:'xyz'}
];
// Use regular SQL
console.log(db.exec("SELECT * FROM students "
+" WHERE ([studentID] = 55 AND school='abc') AND ([City]='xyz' OR [City] ='abc')"));
Try this example in jsFiddle .
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