pgsql: Docs: add example clarifying use of nested JSON containment.

Docs: add example clarifying use of nested JSON containment.

Show how this can be used in practice to make queries simpler and more
flexible.  Also, draw an explicit contrast to the existence operator,
which doesn't work that way.

Peter Geoghegan and Tom Lane

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/626f9be8db11521745711aa3b29e304ab5902a9c

Modified Files
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doc/src/sgml/json.sgml |   28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)