How to query/ find a single element in a JSON array with linq.js

Question

I have a JSON array (javascript). I am using linq.js to filter/query the array and find a single element/first element. What is the correct syntax?

My data:

[{
    "Fname": "Chinmaya",
    "Lname": "Bhatta",
    "DOB": "/Date(328645800000)/",
    "PassportNumber": "",
    "Expirydate": "/Date(315513000000)/",
    "Mobilenum": "91-9740814702",
    "EmailID": "[email protected]",
    "IssueCountry": ""
},
    ...
]

My code:

var tbl =  $(this).closest('table');

var fname= $(tbl).find('[id*=txtFirstName]').val();

var lname= $(tbl).find('[id*=txtLastName]').val();

var filtered = Enumerable.From(fulllist)
                         .Select("$.Fname + ':'+ $.fname+")
                         .ToArray();

But it is throwing error. Can someone tell me what is the right syntax for querying based on Fname & Lname? BTW fulllist is the name of my array.

Thanks in advance.

nbrooks · Accepted Answer · 2014-08-04 07:42:17Z

2

jsFiddle

Just like with a SQL query, you have to specify your 'where' clause to filter the results from the entire dataset:

var filtered = Enumerable
            .From(data)
            .Where("$.Fname == '" + fname + "' && $.Lname == '" + lname + "'")
            .Select("$.Fname + ':' + $.Lname + ':' + $.DOB")
            .ToArray();

You can also use the explicit form of the Where syntax which accepts a callback function:

Where(function (x) { return x.Fname == fname && x.Lname == lname });

Edit

To have your filtered result set be an array of JS obects, remove the call to Select (jsFiddle 2):

var filtered = Enumerable
               .From(data)
               .Where("$.Fname == '" + fname + "' && $.Lname == '" + lname + "'")
               .ToArray();

edited Aug 4, 2014 at 7:42

answered Aug 4, 2014 at 7:01

nbrooks

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6 Comments

santubangalore Over a year ago

Hi nbrooks, thank you for quick response. It returns all the matching values. Actually I wanted only one row/one record only. Second, how to access the data of the single record in javascript code?

santubangalore Over a year ago

Hi nbrooks, this method, only returns the values, not the filed names. I wanted it like {"Fname": "Chinmaya", "Lname": "Bhatta"} format. But I am getting only the values. Pls help me out.

nbrooks Over a year ago

@santubangalore Do you want your result to be a string, or an object? See edit above, which returns the result as an object.

santubangalore Over a year ago

Hi nbrooks, thanks, my second problem is solved by this, but the first problem still remains. i.e. I wanted only one row/record, but I am getting multiple rows. How do I filter it to only one row? And access the data items from javascript code?

nbrooks Over a year ago

@santu My demo above is filtering the resultset to a single row, and is also logging the result (with JavaScript) to the console. If something isn't working, please edit your question to describe both the expected and actual results, and edit the jsfiddle (or make your own) to reproduce the problem.

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