WHERE clause on an array in Azure DocumentDb

Question

In an Azure Documentdb document like this

{
\"id\": \"WakefieldFamily\",
\"parents\": [
    { \"familyName\": \"Wakefield\", \"givenName\": \"Robin\" },
            


        

Answer 1

You should take advantage of DocumentDB's JOIN clause, which operates a bit differently than JOIN in RDBMs (since DocumentDB deals w/ denormlaized data model of schema-free documents).

To put it simply, you can think of DocumentDB's JOIN as self-joins which can be used to form cross-products between nested JSON objects.

In the context of querying children whose pets given name is "Goofy", you can try:

SELECT 
    f.id AS familyName,
    c AS child,
    p.givenName AS petName 
FROM Families f 
JOIN c IN f.children 
JOIN p IN c.pets
WHERE p.givenName = "Goofy"

Which returns:

[{
    familyName: WakefieldFamily,
    child: {
        familyName: Merriam,
        givenName: Jesse,
        gender: female,
        grade: 1,
        pets: [{
            givenName: Goofy
        }, {
            givenName: Shadow
        }]
    },
    petName: Goofy
}]

Reference: http://azure.microsoft.com/en-us/documentation/articles/documentdb-sql-query/

Edit:

You can also use the ARRAY_CONTAINS function, which looks something like this:

SELECT food.id, food.description, food.tags
FROM food
WHERE food.id = "09052" or ARRAY_CONTAINS(food.tags.name, "blueberries")