queryFilter

Filters query rows specified in filter criteria

queryFilter(query, function(row [, currentRow] [, query] ){} [, parallel] [, maxThreads]) → returns query

Member Function Syntax

query.filter(function(row [, currentRow] [, query] ){} [, parallel] [, maxThreads])

Argument Reference

query query
Required

The query to filter

callback boolean
Required

Closure or a function reference that will be called for each of the iteration. Returns true if the row should be included in the filtered query.

Callback parameters:

row* struct : A struct with all of the columns for the current iteration
currentRow* numeric : The row number for the current iteration
query* query : A reference of the original query

parallel boolean
Default: `false`

Lucee 4.5+ CF 2021+ true if the items can be executed in parallel

Values:

true
false

maxThreads numeric
Default: `20`

Lucee 4.5+ CF 2021+ the maximum number of threads to use when parallel = true

Compatibility

ColdFusion:

Version 2016+ queryFilter mutated the original query in CF2016 and 2018 (bug report: https://tracker.adobe.com/#/view/CF-4203366)

Links more information about queryFilter

Map, Reduce and other Higher Order Functions - A Primer for map, reduce, filter, and Higher Order Functions in general.
ColdFusion 2016: query iteration functions - A look at the higher-order functions that queries have

Examples
Sample code invoking the queryFilter function

Filter a query

news = queryNew("id,type,title", "integer,varchar,varchar");
    queryAddRow(news,[{
        id: 1,
        type: "book",
        title: "Cloud Atlas"
    },{
        id: 2,
        type: "book",
        title: "Lord of The Rings"
    },{
        id: 3,
        type: "film",
        title: "Men in Black"
    }]);
    books = queryFilter(news,function(_news) {
        return _news.type is 'book';
    });
    writeDump(valueList(books.title,', '));

Expected Result: Cloud Atlas, Lord of The Rings

Filter a query as member function

news = queryNew("id,type,title", "integer,varchar,varchar");
    queryAddRow(news,[{
        id: 1,
        type: "book",
        title: "Cloud Atlas"
    },{
        id: 2,
        type: "book",
        title: "Lord of The Rings"
    },{
        id: 3,
        type: "film",
        title: "Men in Black"
    }]);
    books = news.filter(function(_news) {
        return _news.type is 'book';
    });
    writeDump(valueList(books.title,', '));