I have a JSONB field that sometimes has nested keys. Example:
{"nested_field": {"another URL": "foo", "a simple text": "text"},
"first_metadata": "plain string",
"another_metadata": "foobar"}
If I do
.filter(TestMetadata.metadata_item.has_key(nested_field))
I get this record.
How can I search for existence of the nested key? ("a simple text"
)
With SQLAlchemy the following should work for your test string:
class TestMetadata(Base):
id = Column(Integer, primary_key=True)
name = Column(String)
metadata_item = Column(JSONB)
as per SQLAlchemy documentation of JSONB
(search for Path index operations example):
expr = TestMetadata.metadata_item[("nested_field", "a simple text")]
q = (session.query(TestMetadata.id, expr.label("deep_value"))
.filter(expr != None)
.all())
which should generate the SQL
below:
SELECT testmetadata.id AS testmetadata_id,
testmetadata.metadata_item #> %(metadata_item_1)s AS deep_value
FROM testmetadata
WHERE (testmetadata.metadata_item #> %(metadata_item_1)s) IS NOT NULL
-- @params: {'metadata_item_1': u'{nested_field, a simple text}'}