---
layout: default
navsection: userguide
+navmenu: Tutorials
title: "Querying the Metadata Database"
-navorder: 116
+navorder: 16
---
h1. Tutorial: Querying the Metadata Database
We query the "links" resource to find humans that report the selected trait. Links are directional connections between Arvados data items, for example, from a human to their reported traits.
<notextile>
-<pre><code>>>> <span class="userinput">query = json.dumps({
+<pre><code>>>> <span class="userinput">trait_query = json.dumps({
'link_class': 'human_trait',
'tail_kind': 'arvados#human',
'head_uuid': non_melanoma_cancer
The query will return links that match all three conditions.
<notextile>
-<pre><code>>>> <span class="userinput">trait_links = arvados.api().links().list(limit=1000, where=query).execute()</span>
+<pre><code>>>> <span class="userinput">trait_links = arvados.api().links().list(limit=1000, where=trait_query).execute()</span>
</code></pre>
</notextile>
<notextile>
<pre><code>>>> <span class="userinput">human_uuids = map(lambda l: l['tail_uuid'], trait_links['items'])</span>
+>>> <span class="userinput">human_uuids</span>
[u'1h9kt-7a9it-c0uqa4kcdh29wdf', u'1h9kt-7a9it-x4tru6mn40hc6ah',
u'1h9kt-7a9it-yqb8m5s9cpy88i8', u'1h9kt-7a9it-46sm75w200ngwny',
u'1h9kt-7a9it-gx85a4tdkpzsg3w', u'1h9kt-7a9it-8cvlaa8909lgeo9',
h2. Find genomic data from specific humans
-Now we want to find collections in Keep that were provided by these humans.
+Now we want to find collections in Keep that were provided by these humans. We search the "links" resource for "provenance" links that point to subjects in list of humans with the non-melanoma skin cancer trait:
<notextile>
-<pre><code>
->>> <span class="userinput">human_uuids = map(lambda l: l['uuid'], pgpid_links['items'])</span>
->>> <span class="userinput">provenance_links = arvados.api().links().list(limit=1000, where=json.dumps({
+<pre><code>>>> <span class="userinput">provenance_links = arvados.api().links().list(limit=1000, where=json.dumps({
"link_class": "provenance",
"name": "provided",
"tail_uuid": human_uuids
- })).execute()</span>
->>> <span class="userinput">collection_uuids = map(lambda l: l['head_uuid'], provenance_links)</span>
+ })).execute()
+collection_uuids = map(lambda l: l['head_uuid'], provenance_links['items'])
# build map of human uuid -> PGP ID
pgpid = {}
-for pgpid_link in pgpid_links:
+for pgpid_link in pgpid_links['items']:
pgpid[pgpid_link['head_uuid']] = pgpid_link['name']
# build map of collection uuid -> PGP ID
-for p_link in provenance_links:
+for p_link in provenance_links['items']:
pgpid[p_link['head_uuid']] = pgpid[p_link['tail_uuid']]
# get details (e.g., list of files) of each collection
collections = arvados.service.collections().list(where=json.dumps({
"uuid": collection_uuids
- })).execute()['items']
+ })).execute()
# print PGP public profile links with file locators
-for c in collections:
+for c in collections['items']:
for f in c['files']:
print "https://my.personalgenomes.org/profile/%s %s %s%s" % (pgpid[c['uuid']], c['uuid'], ('' if f[0] == '.' else f[0]+'/'), f[1])
-</code></pre>
-</notextile>
-
-%(darr)↓%
-
-<pre>
+</span>
+https://my.personalgenomes.org/profile/hu43860C a58dca7609fa84c8c38a7e926a97b2fc var-GS00253-DNA_A01_200_37-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/huB1FD55 ea30eb9e46eedf7f05ed6e348c2baf5d var-GS000010320-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/huDF04CC 4ab0df8f22f595d1747a22c476c05873 var-GS000010427-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/hu7A2F1D 756d0ada29b376140f64e7abfe6aa0e7 var-GS000014566-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/hu553620 7ed4e425bb1c7cc18387cbd9388181df var-GS000015272-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/huD09534 542112e210daff30dd3cfea4801a9f2f var-GS000016374-ASM.tsv.bz2
+https://my.personalgenomes.org/profile/hu599905 33a9f3842b01ea3fdf27cc582f5ea2af var-GS000016015-ASM.tsv.bz2
https://my.personalgenomes.org/profile/hu43860C a58dca7609fa84c8c38a7e926a97b2fc+302+K@qr1hi var-GS00253-DNA_A01_200_37-ASM.tsv.bz2
https://my.personalgenomes.org/profile/huB1FD55 ea30eb9e46eedf7f05ed6e348c2baf5d+291+K@qr1hi var-GS000010320-ASM.tsv.bz2
https://my.personalgenomes.org/profile/huDF04CC 4ab0df8f22f595d1747a22c476c05873+242+K@qr1hi var-GS000010427-ASM.tsv.bz2
https://my.personalgenomes.org/profile/hu553620 ea4f2d325592a1272f989d141a917fdd+85+K@qr1hi Devenwood_results.zip
https://my.personalgenomes.org/profile/hu7A2F1D 4580f6620bb15b25b18373766e14e4a7+85+K@qr1hi Innkeeper_results.zip
https://my.personalgenomes.org/profile/huD09534 fee37be9440b912eb90f5e779f272416+82+K@qr1hi Hallet_results.zip
-</pre>
+</code></pre>
+</notextile>
-h3. Search for a variant.
+h3. Search for a variant
-Look for variant rs1126809 in each of the "var" files (these contain variant calls from WGS data).
+Now we will use crunch to issue a 'grep' job to look for variant rs1126809 in each of the "var-" files (these contain variant calls from WGS data).
-<pre>
-job = {}
-for c in collections:
+<notextile>
+<pre><code>>>> <span class="userinput">job = {}
+for c in collections['items']:
if [] != filter(lambda f: re.search('^var-.*\.tsv\.bz2', f[1]), c['files']):
job[c['uuid']] = arvados.service.jobs().create(body={
'script': 'grep',
'script_version': 'e7aeb42'
}).execute()
print "%s %s" % (pgpid[c['uuid']], job[c['uuid']]['uuid'])
+</span>
+hu43860C qr1hi-8i9sb-wbf3uthbhkcy8ji
+huB1FD55 qr1hi-8i9sb-scklkiy8dc27dab
+huDF04CC qr1hi-8i9sb-pg0w4rfrwfd9srg
+hu7A2F1D qr1hi-8i9sb-n7u0u0rj8b47168
+hu553620 qr1hi-8i9sb-k7gst7vyhg20pt1
+huD09534 qr1hi-8i9sb-4w65pm48123fte5
+hu599905 qr1hi-8i9sb-wmwa5b5r3eghnev
+hu43860C qr1hi-8i9sb-j1mngmakdh8iv9o
+huB1FD55 qr1hi-8i9sb-4j6ehiatcolaoxb
+huDF04CC qr1hi-8i9sb-n6lcmcr3lowqr5u
+hu7A2F1D qr1hi-8i9sb-0hwsdtojfcxjo40
+hu553620 qr1hi-8i9sb-cvvqzqea7jhwb0i
+huD09534 qr1hi-8i9sb-d0y0qtzuwzbrjj0
+hu599905 qr1hi-8i9sb-i9ec9g8d7rt70xg
+</code></pre>
+</notextile>
-</pre>
-
-↓
-
-<pre>
-hu43860C qr1hi-8i9sb-wyqq2eji4ehiwkq
-huB1FD55 qr1hi-8i9sb-ep68uf0jkj3je7q
-huDF04CC qr1hi-8i9sb-4ts4cvx6mbtcrsk
-hu7A2F1D qr1hi-8i9sb-5lkiu9sh7vdgven
-hu553620 qr1hi-8i9sb-nu4p6hjmziic022
-huD09534 qr1hi-8i9sb-bt9389e9g3ff0m1
-hu599905 qr1hi-8i9sb-ocg0i8r75luvke3
-</pre>
Monitor job progress by refreshing the Jobs page in Workbench, or by using the API:
-<pre>
-map(lambda j: arvados.service.jobs().get(uuid=j['uuid']).execute()['success'], job.values())
-</pre>
-
-%(darr)↓%
-
-<pre>
-[True, True, True, True, True, True, True]
-</pre>
+<notextile>
+<pre><code>>>> <span class="userinput">map(lambda j: arvados.service.jobs().get(uuid=j['uuid']).execute()['success'], job.values())
+[None, True, None, None, None, None, None, None, None, None, None, None, None, None]
+</code></pre>
+</notextile>
-(Unfinished jobs will appear as None, failed jobs as False, and completed jobs as True.)
+Unfinished jobs will appear as None, failed jobs as False, and completed jobs as True.
After the jobs have completed, check output file sizes.
-<pre>
-for collection_uuid in job:
+<notextile>
+<pre><code>>>> <span class="userinput">for collection_uuid in job:
job_uuid = job[collection_uuid]['uuid']
job_output = arvados.service.jobs().get(uuid=job_uuid).execute()['output']
output_files = arvados.service.collections().get(uuid=job_output).execute()['files']
- print "%s %3d %s" % (pgpid[collection_uuid], output_files[0][2], job_output)
-
-</pre>
-
-%(darr)↓%
-
-<pre>
-hu599905 80 5644238bfb2a1925d423f2c264819cfb+75+K@qr1hi
-huD09534 80 f98f92573cf521333607910d320cc33b+75+K@qr1hi
-huB1FD55 0 c10e07d8d90b51ee7f3b0a5855dc77c3+65+K@qr1hi
-hu7A2F1D 80 922c4ce8d3dab3268edf8b9312cc63d4+75+K@qr1hi
-hu553620 0 66da988f45a7ee16b6058fcbe9859d69+65+K@qr1hi
-huDF04CC 80 bbe919451a437dde236a561d4e469ad2+75+K@qr1hi
-hu43860C 0 45797e38410de9b9ddef2f4f0ec41a93+76+K@qr1hi
-</pre>
+ # Test the output size. If greater than zero, that means 'grep' found the variant
+ if output_files[0][2] > 0:
+ print("%s has variant rs1126809" % (pgpid[collection_uuid]))
+ else:
+ print("%s does not have variant rs1126809" % (pgpid[collection_uuid]))
+</span>
+hu553620 does not have variant rs1126809
+hu43860C does not have variant rs1126809
+hu599905 has variant rs1126809
+huD09534 has variant rs1126809
+hu553620 does not have variant rs1126809
+huB1FD55 does not have variant rs1126809
+huDF04CC has variant rs1126809
+hu7A2F1D has variant rs1126809
+hu7A2F1D has variant rs1126809
+hu599905 has variant rs1126809
+huDF04CC has variant rs1126809
+huB1FD55 does not have variant rs1126809
+huD09534 has variant rs1126809
+hu43860C does not have variant rs1126809
+</code></pre>
+</notextile>
-Thus, of the 7 WGS results available for PGP participants reporting non-melanoma skin cancer, 4 include the rs1126809 / TYR-R402Q variant.
+Thus, of the 14 WGS results available for PGP participants reporting non-melanoma skin cancer, 8 include the rs1126809 variant.
projects / arvados.git / blobdiff