Technical Articles
Creating an SAC Geo Map from WebIDE (HDI) based Calculation Views
In this blog post I will share how to create an SAP Analytics Cloud (SAC), Geo Map based on Calculation Views created within the WebIDE. These are Calc Views that reside within an HDI Container as Column Views.
Pre-requisites
- HANA Cloud / HANA On-Prem with XSA
- Live Connection from SAC to HANA
- Dataset with Latitude and Longitude
- HDI Calculation Views (created via Business Application Studio or WebIDE)
Required Steps
- Create SAP_BOC_SPATIAL namespace
- Spatial Reference 3857
- Location Data
- Create Geo Dimensional Calculation View with ST_POINT
- Associate Calc Views in SAP Analytics Cloud Model
For the official documentation please see the SAP Analytics Cloud Help
1. Create SAP_BOC_SPATIAL namespace
For the SAC Location Dimension to be identified, your calculation view needs the correct namespace. The namespace needs to be SAP_BOC_SPATIAL
There are two ways to different ways to achieve this.
Choose either the subfolder setting or the global setting.
1a. Specify the namespace at a specific sub-folder level
This can be done by creating a .hdinamespace file in a subfolder and that sub-folder will use that setting.
Figure 1a: Subfolder Project Setting db/src/calc_views/Spatial
{
"name": "SAP_BOC_SPATIAL",
"subfolder": "ignore"
}
1b. Use the global project setting to append the hdinamespace setting as below
Figure 1b: Global Project Setting db/src/.hdinamespace
"subfolder": "append"
Warning, if you change an existing project using “ignore” then some re-work will be required.
With the Global namespace setting you the require a SAP_BOC_SPATIAL folder
SAP Analytics Cloud looks for location data inside the namspsace SAP_BOC_SPATIAL.
This should be created inside the WebIDE project src folder.
Figure 2: SAP_BOC_SPATIAL folder
3. Spatial Reference 3857
For SAC to visualise the location data, HANA must have the Spatial Reference 3857 available.
We can check this with the public synonym ST_SPATIAL_REFERENCE_SYSTEMS.
Figure 3: ST_SPATIAL_REFERENCE_SYSTEMS – 3857
If you do NOT see the SRS_ID 3857 then you can execute the SQL below to add that
CREATE SPATIAL REFERENCE SYSTEM "WGS 84 / Pseudo-Mercator" IDENTIFIED BY 3857 TYPE PLANAR
SNAP TO GRID 1e-4
TOLERANCE 1e-4
COORDINATE X BETWEEN -20037508.3427892447 AND 20037508.3427892447 COORDINATE Y BETWEEN -19929191.7668547928 AND 19929191.766854766 ORGANIZATION "EPSG" IDENTIFIED BY 3857
LINEAR UNIT OF MEASURE "metre"
ANGULAR UNIT OF MEASURE NULL POLYGON FORMAT 'EvenOdd'
STORAGE FORMAT 'Internal'
DEFINITION 'PROJCS["Popular Visualisation CRS / Mercator",GEOGCS["Popular Visualisation CRS",DATUM["Popular_Visualisation_Datum",SPHEROID["Popular Visualisation Sphere",6378137,0,AUTHORITY["EPSG","7059"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY[ "EPSG","6055"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree", 0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4055"]],UNIT[ "metre",1,AUTHORITY["EPSG","9001"]],PROJECTION["Mercator_1SP"],PARAMETER["cen tral_meridian",0],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PA RAMETER["false_northing",0],AUTHORITY["EPSG","3785"],AXIS["X",EAST],AXIS["Y", NORTH]]'
TRANSFORM DEFINITION '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null
+wktext +no_defs'
4. Location Data
The location dataset must not contain duplicate values. To perform the correct join SAC requires a unique list of locations to ensure referential integrity of your model. This dataset will need latitude, longitude data and a field that joins to other Calc Views.
Here I have the table of UK Local Authorities, LAD2019_WKT, sorted on the field lad19cd, which I can see is unique.
Figure 4: Location Dataset
5. Create Geo Dimensional Calculation View with ST_POINT
We can now create a new dimensional Calculation View inside the SAP_BOC_SPATIAL folder. Notice how the Namespace field is populated with the required folder name.
Figure 5: New Dimensional Calc View, notice the Namespace: SAP_BOC_SPATIAL
The output column names need to be unique across the two calculation views that you are using with SAC. I therefore appended _geo to the end of the lad19cd and lad19nm.
Figure 6: Location Dimensional Calculation View
Create Calculated Column of data type ST_POINT.
Using the fields “long” and “lat” we generate the ST_POINT column that SAP Analytics Cloud requires using the SRS 3857.
ST_Transform(ST_GeomFromText('POINT(' || "long" || ' ' || "lat" || ')', 4326),3857)
Figure 7: Calculated Column, LOCAL_AUTHORITY_GEO ST_POINT
By specifying the “Key” column, SAC can identify which is the description field as it won’t be the key.
Figure 7.1: Specify the Key Field
We can Save and Build the Calculation View.
Figure 8: Build Calculation View
We can find our Calculation View as a Column View. Note how the name is prefixed with SAP_BOC_SPATIAL (the subfolder we created in step 2.)
Figure 9: Database Explorer Column View
We should data preview it to verify it works as expected. Note how the name is again prefixed with SAP_BOC_SPATIAL.
Figure 10: Data Preview of Local Authority Calc View
6. Associate Calc Views in SAP Analytics Cloud Model
Open an existing SAC Model that will join to the fields exposed in the above model, in my case I can join on either lad19cd_geo or lad19nm_geo. Click the “Location Dimension” button.
Figure 11: Open Existing SAC HANA Model
We need to associate our Geo Dimensional Calc View with an existing calculation view.
The Location Identifier comes from an existing calculation view, this is the Attribute Column that joins to the Identifier for Mapping column coming from the step 5 “Geo Dimensional Calculation View”. In my case Area_code joins to lad19cd_geo. This would be a 1:1 or many:1 with the many coming from the existing calculation view.
Figure 12: Create Location Dimension
The final test is to create a Geo Map using this model to verify both the data and locations are displayed correctly on the map.
Figure 13: SAP Analytics Cloud Geo Map
Conclusion
Spatial data has become more prevalent within the Enterprise, using SAP Analytics Cloud with HANA is a convenient way to visual this. From this blog post you can understand how SAP Business Application Studio or WebIDE based Calculation Views from HANA or HANA Cloud can be consumed live.
Hi Ian,
Thank you for posting.
Let me ask you some questions below.
We are following your procedure of Geo Map based on Calculation Views created within the WebIDE but it doesn't work well because of an error message at step number 6.
The error message is "You have no authorization to the model".
I don't know why it happens because I have created the model by myself and put it in the public folder.
HDI container we are using is HANA Service available at SCP (Cloud Foundry) Environment.
Please kindly give us your advice.
Thanks Keito,
Glad it's useful.
The error suggests that the user making the live connection to HANA does not have the rights on one of the calc views. How are you connecting to HANA? I am using the HAA with a predefined user/HDI container.
If your calc view linked to "test_kk1" is from a different HDI container you would need to give the access role or similar role to the user.
You can check the Chrome -> View -> Developer Tools -> Console for more information
Check which user is SAC using to connect to HANA, then log with that user in DB Explorer and try to select from the same calc view. Chances are you’ll get the same error.
Like Ian said, you need to authorize that user to be able to select from the HDI Container objects.
The easiest way is to create a design time role in your HDI Container project with the SELECT object privilege, then to grant this role to the DB User SAC uses to connect to HANA. See the second option mentioned on this blog for more details: https://blogs.sap.com/2018/01/24/the-easy-way-to-make-your-hdi-container-accessible-to-a-classic-database-user/
Hello together,
In an existing project on XSA we have add a calculation view as described in this blog.
After building and deploying the changes we can see the new calculation view in the column views.
But unfortunately on SAP Analytics Cloud we are not able to see the view as described in "Figure 12: Create Location Dimension". The dropdown is empty and I don't get any error.
Do you have any idea what wen't wrong?
Best regards,
Michel
Hi Michel,
I would double check that your dataypes are consistent, you need a common dimension datatype to join with from your 2 views. Confimrm ST_POINT Calc View object is using the 3857 SRS_ID. This can be done with some syntax similar to this.
Dear Ian
Thank you very much for your answer, I checked in the system and can confirm that every single entry has 3857 SRS_ID:
Do you have any other idea?
I guess you are joining on STANDORTID_LD? Can you double check the datatype for that that and whichever column you are trying to join with?
Can you also check for duplicates?
If that's not given any clues, check SAC, Chrome Developer Tools. Clear the console before you press the location dimension and then check what you see there.
Hi Ian,
thank you for your input.
As described by your blog I did already the necessary work to remove the duplicates:
Duplicate check
On SAC I don't see any error. Even all networking requests are sucessful.
Chrome Console-Tab
Chrome Networktab
Do you have any other idea?
Thanks in advanced.
Best regards
Michel
Can you double check data types from both views?
Hello,
I just had the same issue.
- Location dimension calculation view was created and activated correctly.
- No duplicates in the location dimension calculation view.
- Correct SRID set up.
However, the view was not visible from SAC. The solution is to build the whole project from business application studio.
You MUST activate the whole project containing the location dimension calculation view and the .hdinamespace file so that it becomes visible from SAC.
Hello Ian Henry and Henrique Pinto,
thank you for the detailed explanation. We have yet completed all the steps you showed above. We are currently stuck in SAC, Create Location Dimension pop up window. No view suggestion appears in the Location Data View name dropdown list. We are assuming, that we have a similar problem as Michel.
SAC Create Location Dimension Popup
Ian Henry Is this something that you have seen before, could you help us out with this issue?
Dimension View created
Best regards,
Chia-Yu
Hi Chia-Yu,
As mentioned above please check your spatial reference ID is 3857 and that you have no duplicate records on the column you are joining with from the Location Dimension.
Hello,
I just had the same issue.
- Location dimension calculation view was created and activated correctly.
- No duplicates in the location dimension calculation view.
- Correct SRID set up.
However, the view was not visible from SAC. The solution is to build the whole project from business application studio.
You MUST activate the whole project containing the location dimension calculation view and the .hdinamespace file so that it becomes visible from SAC.
Hello Ian Henry
When creating an .hdinamespace in an existent project we need to prefix all the artifacts already created? or there is any other solution.
Thank you very much for sharing your knowledge with the community.
Best Regards,
Elson
Hi Elson,
Yes, there is another solution 🙂
You can create a .hdinamespace file in the SAP_BOC_SPATIAL folder like below.
You will then need to rename/refactor your calc view so that the namespace is included in the name.
It then should appear with the SAP_BOC_SPATIAL when you view the column view.
Dear Ian,
Thank you very much!! It worked as supposed 🙂
Have a nice end of week/weekend!
Hi Ian,
Thank you for posting! I have completed all the steps you showed above and I created a Location Dimension in SAC correctly but when I use it in a Geo map this error appears:
Caught exception : exception 1600301: Expected a coordinate, but found ',' instead at position 9 of WKT POINT(-58,557012 -34,619977 )
ID de correlación: 17119703-4624-4172-9057-089589752342
error
I already checked and I have no duplicated records. And I also checked if there is a comma in the lat and long values but there isn't.
data geo_dimension
Do you know why this error ocurrs?
Thanks!
Liliana Cantero
Ian:
This was an incredibly helpful post as we did considerable searching and only saw guidance on how to accomplish in the SAP HANA Studio and not SAP Cloud Platform. We used your approach with SAP Business Application Studio.
Thank you for taking time to share. Like others, we were not getting the Location View to show in SAP Analytics Cloud in our initial attempt, but rebuilt a new project with the namespace added before other artifacts and it worked.
I should have read the comments more closely as I believe your Dec 3rd solution would have solved our original issue without the need to rename existing artifacts.
Thanks,
Neil Uebelein
Thanks for the feedback Neil,
Glad you got it working.
If you have some Choropleth layers I have a blog on that coming soon.
I will update the body of the blog to include those details about the namespace. Hopefully should save others some time too.
Hi Ian,
thank you for your tutorial. It was very helpful, but I have done all steps in your tutorial and then I get this error. After adding the Location Dimension to the Layer the map moves to the right position but no points are shown. Also every time I move the map, the error message appears again. I already checked the browser console, but there is no error or additional information.
Could you help me? Or do you have some tips?
Thanks,
Niklas
Can you click, expand and share the error details?
Chrome Developer Tools (F12), console tab can sometimes provide additional details.
When I click expand I only get a Correlation ID. For example:
"Correlation ID: 15438218-2720-4933-9171-819573543933"
There are no additional details in the developer tools either.
Hi Lan,
i tried every way: 1b return error while building.
1a not, but my SAC Model doesn't see my location View.
I tried also this way but my issue still the same:
Checking Column View on my space i see my View:
with correct data:
what am I doing wrong?
Hi David,
Something to check.
Cheers, Ian.
I
I tried, but it seems correct, maybe Hana version? or because i'm using Business Application?
Hi Davide,
Business Application Studio is fine. I have also developed Calculation Views this way.
Are both your Calc Views in the same HDI container?
Hi Ian, I solved issue. The problem was pending activation on package SAP_BOC_SPATIAL (not calculation view).
Hi Ian,
First of all, a very big thank you to you for providing this information so well presented here. Without you we would be hopelessly lost!
We have followed your steps meticulously, but get the following error message when previewing the data in Business Application Studio:
Obviously the calculation of the coordinate is wrong. But we can't find any error here:
Just so you see that "lat" and "long" are actually coordinates, here is the data preview of the data source:
Thank you very much and best regards,
Benedikt
Seems you're missing a space between lon and lat when assembling the WKT. Just add the space in your expression and you should be good.
Thanks Mathias, that solved it!
Hi Ian,
Thanks for sharing such detailed steps, easy to follow.
I have followed your tutorial step by step till the end, however, I encounter issue on last step. The GeoMap simply did not show the location. To simplified my learning, I use the same geoloc data as yours, but I only copy the first 3 lines:
I have checked every single step, no issue. Need some guide, thank you.
Hi Jin Wei Min,
Happy to share and glad it's useful for you.
In terms of troubleshooting there's a few places to check.
Let me know what you find.
Thanks, Ian.