javascript - PouchDb fetch all documents by Id matching regex - Stack Overflow

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I would like to get all documents with id matching a regex expression.

For example I have the following doc ids:

p0
p0/e0
p1
p1/e0

How can I get only p0 and p1 ? Regex would be /^p[0-9]+$/

Currently I can do it performing two requests, but I would like to use only one:

This.db.allDocs({
    include_docs: false
}).then(function(result){

    // Find all ids matching /^p[0-9]+$/
    var iDoc = result.rows.length;
    while(iDoc--){
        if(result.rows[iDoc].id.match(/^p[0-9]+$/)){
            projectsIds.push(result.rows[iDoc].id);
        }
    }

    // Get all documents with ids matching /^p[0-9]+$/
    This.db.allDocs({
        include_docs: true,
        keys: projectsIds
    }).then(function(result) {
        var iProject = result.rows.length;
        var docs = [];
        while (iProject--) {
            docs[iProject] = result.rows[iProject].doc;
        }
        projects.resolve(docs);

    });

});

I would like to get all documents with id matching a regex expression.

For example I have the following doc ids:

p0
p0/e0
p1
p1/e0

How can I get only p0 and p1 ? Regex would be /^p[0-9]+$/

Currently I can do it performing two requests, but I would like to use only one:

This.db.allDocs({
    include_docs: false
}).then(function(result){

    // Find all ids matching /^p[0-9]+$/
    var iDoc = result.rows.length;
    while(iDoc--){
        if(result.rows[iDoc].id.match(/^p[0-9]+$/)){
            projectsIds.push(result.rows[iDoc].id);
        }
    }

    // Get all documents with ids matching /^p[0-9]+$/
    This.db.allDocs({
        include_docs: true,
        keys: projectsIds
    }).then(function(result) {
        var iProject = result.rows.length;
        var docs = [];
        while (iProject--) {
            docs[iProject] = result.rows[iProject].doc;
        }
        projects.resolve(docs);

    });

});

• javascript
• pouchdb

Share Improve this question Follow edited May 11, 2015 at 10:42 sylvain1264 asked May 11, 2015 at 9:21 sylvain1264sylvain1264 85522 gold badges88 silver badges2323 bronze badges 1

• what kind of regular expression you use?can you provide more information on that – Bhavesh Jariwala Commented May 11, 2015 at 10:13

Add a ment  | 

3 Answers 3

Sorted by: Reset to default 6

this possible to get document by prefix, for example

localDB.allDocs({
            include_docs: true,
            startkey: "p0",
            endkey: "p0\uffff"
        },...);

above code gives you all document which _id is start with p0.

refer link https://github./nolanlawson/pouchdb-quick-search#autosuggestions-and-prefix-search

You need to fetch all your docs using allDocs() and then filter in memory using JavaScript.

This requires reading your entire database into memory, but PouchDB cannot index on a regex, so it's what you have to do! Else you can design your IDs so that it's easier to do prefix searching as described by the other menter.

A few years later and it looks like pouchdb-find plugin might have helped (written by @nlawson above, i think). Here's the Pouch docs talking about querying with it... https://pouchdb./api.html#query_index

And how you'd do it:

async test()
  let result = await This.db.find({
    selector: {_id: {$regex: '^p[0-9]+$'}}
  });
  let docs = result.rows.map( row => row.doc )
  console.dir(docs)
}

(i made it async just so you don't have to faff about with callbacks)

You can try it out for yourself on pouchdb-find plugin's site.

Performance may be terrible though, I've not tried it. @nlawson seems to think a regex on an index can't be done quickly and he surely knows better than most.

EDIT: I just checked the Pouch docs mentioned above and indexes are definitely used during the find process, so performance might be ok.

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