GitHub user 0x0FFF opened a pull request:
https://github.com/apache/spark/pull/8948
[SPARK-7869][SQL] Adding Postgres JSON and JSONb data types support
This PR addresses
[SPARK-7869](https://issues.apache.org/jira/browse/SPARK-7869)
Before the patch, attempt to load the table from Postgres with JSON/JSONb
datatype caused error `java.sql.SQLException: Unsupported type 1111`
Postgres data types JSON and JSONb are now mapped to String on Spark side
thus they can be loaded into DF and processed on Spark side
Example
Postgres:
```
create table test_json (id int, value json);
create table test_jsonb (id int, value jsonb);
insert into test_json (id, value) values
(1, '{"field1":"value1","field2":"value2","field3":[1,2,3]}'::json),
(2, '{"field1":"value3","field2":"value4","field3":[4,5,6]}'::json),
(3, '{"field3":"value5","field4":"value6","field3":[7,8,9]}'::json);
insert into test_jsonb (id, value) values
(4, '{"field1":"value1","field2":"value2","field3":[1,2,3]}'::jsonb),
(5, '{"field1":"value3","field2":"value4","field3":[4,5,6]}'::jsonb),
(6, '{"field3":"value5","field4":"value6","field3":[7,8,9]}'::jsonb);
```
PySpark:
```
>>> import json
>>> df1 =
sqlContext.read.jdbc("jdbc:postgresql://127.0.0.1:5432/test?user=testuser",
"test_json")
>>> df1.map(lambda x: (x.id, json.loads(x.value))).map(lambda (id, value):
(id, value.get('field3'))).collect()
[(1, [1, 2, 3]), (2, [4, 5, 6]), (3, [7, 8, 9])]
>>> df2 =
sqlContext.read.jdbc("jdbc:postgresql://127.0.0.1:5432/test?user=testuser",
"test_jsonb")
>>> df2.map(lambda x: (x.id, json.loads(x.value))).map(lambda (id, value):
(id, value.get('field1'))).collect()
[(4, u'value1'), (5, u'value3'), (6, None)]
```
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/0x0FFF/spark SPARK-7869
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/spark/pull/8948.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #8948
----
commit 1be25157449335dca70ba37720a172efa1f90714
Author: 0x0FFF <[email protected]>
Date: 2015-09-30T10:32:49Z
[SPARK-7869][SQL] Adding Postgres JSON and JSONb data types support
----
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