README.md

Query post code information in batch mode

The example is calling a REST API using the POST method to enrich UK postal codes with county, council and parish information.
The input table has a column postcode. We group the postal codes from several rows together and submit each group in one call.
The column name from the input table is used in the batch repeat structure and the batch data is added to the HTTP payload.
The required fields from the HTTP result are mapped to columns in the output table.

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Demo recreate

Use the following settings to recreate the above example in SAS Studio.

1. Create new flow job in SAS Studio.
2. Drag table 'zip' on the canvas.
   • See here to create table 'zip'.
3. HTTP Request

   • Drag HTTP Request step on canvas and connect with the input table step.
   • Go to tab HTTP Request.
     • Set URL as below.

        http://api.postcodes.io/postcodes
       

     • Set Method to POST.
     • Fill Payload text box with below JSON structure. In the JSON structure we use the columns from the input table as parameters.

        {
          "postcodes" : [@postcode_batch@]
        }
       

   • Go to tab Batch.
     • Set Record group size to 3.
     • Put below data into text box Repeated json structure.
       

       "@postcode@"
       

       This is the repeated data structure the represents one batch record. In this case it is only one field.
     • Put below token variable name into Batch structure name.

       postcode_batch
       

       The token variable name represents the batch data and is used in the payload in tab HTTP Request.
   • Go to tab Input Options.
     • Under Headers set Header Lines to 2.
       • For the first Header Line use default value.
         

          "Content-Type"="application/json"
         

       • For the second Header Line use below setting.
         

          "Accept"="application/json"
         

   • Go to tab Output Options.
     • Under Output Body - Output Table
       
       • Use the below mapping in field Field Mapping to copy fields from the URL JSON result structure to the output table.

           result/0/result/postcode        | postcode_1,
           result/0/result/admin_county    | county_1,
           result/0/result/admin_district  | council_1,
           result/0/result/parish          | parish_1,
           result/1/result/postcode        | postcode_2,
           result/1/result/admin_county    | county_2,
           result/1/result/admin_district  | council_2,
           result/1/result/parish          | parish_2,
           result/2/result/postcode        | postcode_3,
           result/2/result/admin_county    | county_3,
           result/2/result/admin_district  | council_3,
           result/2/result/parish          | parish_3
         

   • Add Output Port.
     • Use right mouse click to add output port to the step.

4. Run Demo
   • Execute Demo Flow.

Test Data

Run this code in SAS Studio to create the input data for the demo.

data zip;
	length postcode $10;
	infile cards dlm=",";
	input postcode $;
	cards;
AL3 8EE
AL4 0RQ
W2 1JU
OX49 5NU
M32 0JG
NE30 1DP
LU6 3DT
;
run;