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Getting Started with Optic

To Delete Documents

The Integration Department has completed their collection of Engineering employees to let go. Along with disbanding the department, management has decided to simply delete the records of the terminated employees.

We must now delete the Attrition Department along with the employee documents associated with that department.

An Optic update like this one deletes documents by their URIs:

declareUpdate();
const op = require("/MarkLogic/optic");
op.fromDocUris(cts.orQuery([
    cts.documentQuery("/data/departments/Attrition.json"),
    cts.collectionQuery('https://example.com/content/department/Attrition')
  ])
  )
  .remove()
  .result();

We used this update to delete the Attrition Department document as well as all employee documents in the Attrition collection:

  • The Data Accessor Function fromDocUris() produces a row for each document with the column uri containing document URIs:

    • The CTS Function cts.orQuery() returns the union of matches that each of its parameter functions finds:

      • cts.documentQuery() finds the document with the specified URI, our Attrition Department.

      • cts.collectionQuery() finds all the data from documents in the specified collection, our Attrition collection.

    • With these CTS functions as parameters, fromDocUris() produces a row with the uri column containing the URI for each document that we want to delete: the Attrition department document and each employee document in the Attrition collection.

  • The Operator Function remove() marks for system deletion the documents whose URIs match the ones in fromDocUris()'s uri column, leaving behind only the uri column.

  • The Executor Function result() executes the update and returns the results as a row sequence.

Here are the first 6 rows of the 1-column result:

{
 "uri": "/data/departments/Attrition.json"
}
{
 "uri": "/data/employees/f7d055a5-9462-424c-8e9b-13db2878145f.json"
}
{
 "uri": "/data/employees/bd5e4f9c-14d5-4f88-89d0-4434fc9318f4.json"
}
{
 "uri": "/data/employees/2ef6c49b-ac42-4f83-b887-e31394843ef9.json"
}
{
 "uri": "/data/employees/67ba986d-af98-49ee-b731-5b230853ad53.json"
}
{
 "uri": "/data/employees/9a4d5d9a-e04e-41a7-a2ac-1bd64f6a2edd.json"
}

  • These are the URIs of the deleted documents.

  • Before executing this update, you can check that your fromDocUris() statement will return the URIs of the documents that you want to delete by commenting out remove(). The resulting update returns the rows that fromDocUris() accesses.

  • Use execute() to execute the update without returning the resultant row sequence.

  • With no documents left in it, the Attrition collection automatically vanishes.

You now know how to build Optic updates to insert, update, and delete documents.

In this section: