Hi all,
I had some questions about API requests and asked other developers in the Developers Workspace for support. I got some good responses; therefore, I thought it’d be helpful to have a wiki with helpful questions & responses that the developers in the DHIS2 Community of Practice can contribute to. Thanks!
How to help/contribute?
This is a wiki post which means all community members are welcome to edit it, add a Q&A or helpful tips then tag their CoP usernames at the end of this post. See contributors list at the end of this post.
Helpful API Q&As - API tips:
Q - Can we query for information from two different API endpoints in one request?
@RModi I would suggest to use two different queries and concatenate the result. Might be less daunting.
@tzemp You might be able to structure a single query using nested references … but if you want to access completely different resources from the api (say messageConversations and dataElementOperands) you’d probably need to make multiple requests
Q - How do we structure nested queries?
@tzemp to structure a single query using nested references, e.g. if you want to see the names of categoryOptions associated with a given program, you could use [instanceURL]/api/programs?fields=id,name,categoryCombo[id,name,categories[id,name,categoryOptions[id,name]]]
Q - How do we create filters in API requests?
@tzemp you can put the filters at the end, like: [instanceURL]/2.37.2/api/programs?fields=id,name,categoryCombo[id,name,categories[id,name,categoryOptions[id,name]]]&filter=categoryCombo.categories.name:like:Implementing
Q - How do we create more than one filter in an API request?
@tzemp you’ll need to do concatenate the filter conditions with & like &filter=object:like:something&filter=object2:eq:xyz
Q - Can we add logic to filters in API requests?
@tzemp you can specify a rootJunction if you don’t want to use AND, e.g. &filter=object:like:something&filter=object2:eq:xyz&rootJunction=OR
See Logical Operators section here:
https://docs.dhis2.org/en/full/develop/dhis-core-version-master/developer-manual.html#webapi_metadata_object_filter
Q - What is a ‘deprecated’ API end point?
@austin In general a deprecated api is set to be removed in a future version, so relying on it isn’t recommended.
Q - Why is it not recommended to use fields=*?
@austin you can specify explicit fields within the api end point so you shouldn’t need fields=* (which can create a heavy request)
Q - How can I know if there are dataSets or programStages that contain empty custom forms?
Maybe you can reuse these example API calls 
https://play.dhis2.org/2.36.12/api/dataSets.json?fields=id,name,dataEntryForm[id,htmlCode]&filter=dataEntryForm:!null&filter=dataEntryForm.htmlCode:null
https://play.dhis2.org/2.36.12/api/programStages.json?fields=id,program[name,id],name,dataEntryForm[id,htmlCode]&filter=dataEntryForm:!null&filter=dataEntryForm.htmlCode:null
Q - API response says I need to get an ID for a metadata object, how?
@Gassim Generally, to get an ID of a metadata object, you need to check its API endpoint, here are two important resources that will help you find your way through the API:
- /api/schemas - For example, InstanceURL/api/schemas
** See Schemas docs - /api/resources - For example, InstanceURL/api/resources
** See Resources (the Web API entry point) docs
After that you will request the ID from the end point and use fields and filters to return the required result.
Q - What’s the fastest way to get all the results from the Event Reports app?
Is there a way to retrieve TEIs from multiple programs?
Contributors:
@RModi
@tzemp
@Gassim
@austin
@ctejo
[add your username here after adding a contribution 
]
