# Mongo example
## Overview
* mongo-shell lets you talk directly to mongo
* command is `mongo`
* mongo has multiple databases
* pulp_database is the one we want
* you choose your default-database with `use pulp_database`
* mongo stores documents in collections
* you can show the available collections using `show collections`
* command format is `db.COLLECTION.command`
* example: `db.iso_units.find().count()`
* useful commands
* `.find()`
* `.limit(1)`
* `.count()`
* `.update( {FILTER}, {OPERATION} )`
## Specific annotated example to change the name of one ISO unit:
* Connect

    [root@dhcp-3-121 ~]# mongo
    MongoDB shell version v3.4.9
    connecting to: mongodb://127.0.0.1:27017
    MongoDB server version: 3.4.9
    Server has startup warnings: 
    2022-10-31T10:25:24.788-0400 I CONTROL  [initandlisten] 
    2022-10-31T10:25:24.788-0400 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
    2022-10-31T10:25:24.788-0400 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
    2022-10-31T10:25:24.788-0400 I CONTROL  [initandlisten] 
    2022-10-31T10:25:24.788-0400 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
    2022-10-31T10:25:24.789-0400 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
    2022-10-31T10:25:24.789-0400 I CONTROL  [initandlisten] 

* Choose db

    > use pulp_database
    switched to db pulp_database

* What collections do we have to work with?

    > show collections
    celery_beat_lock
    consumer_bindings
    consumer_history
    consumer_unit_profiles
    content_types
    deferred_download
    erratum_pkglists
    event_listeners
    lazy_content_catalog
    migration_trackers
    orphaned_profile_hash
    permissions
    repo_content_units
    repo_distributors
    repo_group_publish_results
    repo_importers
    repo_profile_applicability
    repo_publish_results
    repo_sync_results
    repos
    reserved_resources
    resource_manager_lock
    roles
    scheduled_calls
    task_status
    units_distribution
    units_docker_blob
    units_docker_image
    units_docker_manifest
    units_docker_manifest_list
    units_docker_tag
    units_drpm
    units_erratum
    units_iso
    units_modulemd
    units_modulemd_defaults
    units_ostree
    units_package_category
    units_package_environment
    units_package_group
    units_package_langpacks
    units_puppet_module
    units_rpm
    units_srpm
    units_yum_repo_metadata_file
    users
    workers
    >  

* How many File units are there?

    > db.units_iso.count()
    2

* Show just one so we know what document-fields look like:

    > db.units_iso.find().limit(1)
    { 
      "_id" : "1f162d5c-2df0-4106-8962-871c60ce4b6e", 
      "pulp_user_metadata" : {  }, 
      "_last_updated" : 1667316670,
      "_storage_path" : "/var/lib/pulp/content/units/iso/05/5fb578119dbf971e7310e6ac06d639bb5af1155089be7ab3c9ad121dd5f6c7", 
      "downloaded" : true, 
      "name" : "2.iso", 
      "checksum" : "d34e9a108c6ee81e094cd6e26955686c9ba9eb036b4f0d64c82ebe1bebb73b5d", 
      "size" : 10485760, 
      "_ns" : "units_iso", 
      "_content_type_id" : "iso" 
    }

* Find specific ISO ("1.iso")

    > db.units_iso.find( {name: { $eq: "1.iso" } })
    { 
      "_id" : "8d939e4f-c743-4bb3-a365-809cdfbb36f8", 
      "pulp_user_metadata" : {  }, 
      "_last_updated" : 1667316670, 
      "_storage_path" : "/var/lib/pulp/content/units/iso/07/b4c128c58e7e1bd281fb03575a71c2371ff0b8656e157d35a6b0aa5b3ecba0",
      "downloaded" : true, 
      "name" : "1.iso", 
      "checksum" : "1c4ef7df278004ece0ba14e0ed69c0a4e69762dc7e12cf7ee150b21ad612f42c", 
      "size" : 10485760, 
      "_ns" : "units_iso", 
      "_content_type_id" : "iso" 
    }

* Change the name of 2.iso to 1.iso

    > db.units_iso.update( {name: { $eq: "2.iso" } }, { $set: {name: "1.iso"}} )
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

* Find 1.iso

    > db.units_iso.find( {name: { $eq: "1.iso" } })
    { "_id" : "8d939e4f-c743-4bb3-a365-809cdfbb36f8", "pulp_user_metadata" : {  }, "_last_updated" : 1667316670, "_storage_path" : "/var/lib/pulp/content/units/iso/07/b4c128c58e7e1bd281fb03575a71c2371ff0b8656e157d35a6b0aa5b3ecba0", "downloaded" : true, "name" : "1.iso", "checksum" : "1c4ef7df278004ece0ba14e0ed69c0a4e69762dc7e12cf7ee150b21ad612f42c", "size" : 10485760, "_ns" : "units_iso", "_content_type_id" : "iso" }
    { "_id" : "1f162d5c-2df0-4106-8962-871c60ce4b6e", "pulp_user_metadata" : {  }, "_last_updated" : 1667316670, "_storage_path" : "/var/lib/pulp/content/units/iso/05/5fb578119dbf971e7310e6ac06d639bb5af1155089be7ab3c9ad121dd5f6c7", "downloaded" : true, "name" : "1.iso", "checksum" : "d34e9a108c6ee81e094cd6e26955686c9ba9eb036b4f0d64c82ebe1bebb73b5d", "size" : 10485760, "_ns" : "units_iso", "_content_type_id" : "iso" }
    > 

* **Rename that actually reproduced the problem we were going after:**

db.units_iso.update(
{
  name: { $eq: "2.iso" } }, 
  { $set: {name: "1.iso/22.iso"} } } 
)