Mango allows users to declaratively define and query Apache CouchDB indexes. Mango leverages Lucene not only to perform text search, but also to enable ad-hoc querying capabilities.

1. Lab: Mango (30 minutes)
Bradley Holt, Developer Advocate
Thursday, February 9, 2017
CouchDB Developer Day
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2. Prerequisite: Replication Lab
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4. Mango
 Declarative indexes
 MongoDB-style query language
 You can still use map/reduce views
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5. http-console
$ npm install http-console -g
@BradleyHolthttps://github.com/cloudhead/http-console

6. http-console
$ npm install http-console -g
$ http-console 127.0.0.1:5984
@BradleyHolthttps://github.com/cloudhead/http-console

7. http-console
$ npm install http-console -g
$ http-console 127.0.0.1:5984
> http-console 0.6.3
> Welcome, enter .help if you're lost.
> Connecting to 127.0.0.1 on port 5984.
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8. Connecting to CouchDB 2.0
$ http-console root:passw0rd@127.0.0.1:5984 --json
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9. Connecting to CouchDB 2.0
$ http-console root:passw0rd@127.0.0.1:5984 --json
> http-console 0.6.3
> Welcome, enter .help if you're lost.
> Connecting to 127.0.0.1 on port 5984.
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10. Connecting to IBM Cloudant
$ http-console https://bradley-holt:passw0rd@bradley-holt.cloudant.com --json
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11. Connecting to IBM Cloudant
$ http-console https://bradley-holt:passw0rd@bradley-holt.cloudant.com --json
> http-console 0.6.3
> Welcome, enter .help if you're lost.
> Connecting to bradley-holt.cloudant.com on port 443.
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12. Mango
/>
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13. Mango
/> /kittens
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14. Mango
/kittens>
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15. Mango
/kittens> POST /_index
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16. Mango
/kittens> POST /_index
...
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17. Mango
/kittens> POST /_index
... { "index": { "fields": [ "age_weeks", "weight_kilograms" ] } }
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18. Mango
/kittens> POST /_index
... { "index": { "fields": [ "age_weeks", "weight_kilograms" ] } }
HTTP/1.1 200 OK
Content-Type: application/json
{
result: 'created',
id: '_design/e19dde7f518129a966ebe072edc66be88d54e694',
name: 'e19dde7f518129a966ebe072edc66be88d54e694'
}
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19. @BradleyHolt

20. Mango
/kittens>
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21. Mango
/kittens> POST /_find
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22. Mango
/kittens> POST /_find
...
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23. Mango
/kittens> POST /_find
... { "selector": { "age_weeks": { "$gte": 7, "$lte": 10 } }, "fields": [ "_id", "age_weeks" ] }
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24. Mango
/kittens> POST /_find
... { "selector": { "age_weeks": { "$gte": 7, "$lte": 10 } }, "fields": [ "_id", "age_weeks" ] }
HTTP/1.1 200 OK
Content-Type: application/json
{
docs: [
{ _id: 'tiger', age_weeks: 7 },
{ _id: 'daisy', age_weeks: 9 },
{ _id: 'mittens', age_weeks: 10 }
]
}
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25. @BradleyHolt

26. Mango
/kittens>
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27. Mango
/kittens> POST /_find
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28. Mango
/kittens> POST /_find
...
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29. Mango
/kittens> POST /_find
... { "selector": { "age_weeks": { "$gte": 0 }, "weight_kilograms": { "$gte": 0.5, "$lte": 1 } }, "fields": [ "_id",
"weight_kilograms" ] }
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30. Mango
/kittens> POST /_find
... { "selector": { "age_weeks": { "$gte": 0 }, "weight_kilograms": { "$gte": 0.5, "$lte": 1 } }, "fields": [ "_id",
"weight_kilograms" ] }
HTTP/1.1 200 OK
Content-Type: application/json
{
docs: [
{ _id: 'tiger', weight_kilograms: 0.726 },
{ _id: 'daisy', weight_kilograms: 0.816 },
{ _id: 'mittens', weight_kilograms: 0.997 }
]
}
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31. @BradleyHolt

32. Try It On Your Own
1. Create an index of kittens by weight_kilograms and age_weeks (in that order)
2. Find kittens weighing less than 1 kilogram who are 7 weeks or older
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33. Image Credit
 Mango with section on a white background by bangdoll, on Flickr <https://flic.kr/p/9CBP2h>
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34. Lab: Mango
CouchDB Developer Day
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