json_direct.py

# -----------------------------------------------------------------------------
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#
# This software is dual-licensed to you under the Universal Permissive License
# (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
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# either license.
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# the following applies:
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# See the License for the specific language governing permissions and
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# -----------------------------------------------------------------------------
# json_direct.py
#
# Demonstrates the use of some JSON features with the JSON type that is
# available in Oracle Database 21c and higher.
#
# See https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=ADJSN
#
# For JSON with older databases see json_blob.py
# -----------------------------------------------------------------------------

importjson
importsys

importoracledb
importsample_env

# determine whether to use python-oracledb thin mode or thick mode
ifnotsample_env.get_is_thin():
oracledb.init_oracle_client(lib_dir=sample_env.get_oracle_client())

connection=oracledb.connect(
user=sample_env.get_main_user(),
password=sample_env.get_main_password(),
dsn=sample_env.get_connect_string(),
params=sample_env.get_connect_params(),
)

ifnotconnection.thin:
client_version=oracledb.clientversion()[0]
db_version=int(connection.version.split(".")[0])

# this script only works with Oracle Database 21
ifdb_version<21:
sys.exit(
"This example requires Oracle Database 21.1 or later. "
"Try json_blob.py instead"
 )

# Insert JSON data
withconnection.cursor() ascursor:
data=dict(name="Rod", dept="Sales", location="Germany")
inssql="insert into CustomersAsJson values (:1, :2)"
ifconnection.thinorclient_version>=21:
# Take advantage of direct binding
cursor.setinputsizes(None, oracledb.DB_TYPE_JSON)
cursor.execute(inssql, [1, data])
else:
# Insert the data as a JSON string
cursor.execute(inssql, [1, json.dumps(data)])

# Select JSON data
withconnection.cursor() ascursor:
sql="select c.json_data from CustomersAsJson c"
ifconnection.thinorclient_version>=21:
for (j,) incursor.execute(sql):
print(j)
else:
for (j,) incursor.execute(sql):
print(json.loads(j.read()))

# Using JSON_VALUE to extract a value from a JSON column

sql="""select json_value(json_data, '$.location')
 from CustomersAsJson
 offset 0 rows fetch next 1 rows only"""
forrincursor.execute(sql):
print(r)

# Using dot-notation to extract a value from a JSON column

sql="""select c.json_data.location
 from CustomersAsJson c
 offset 0 rows fetch next 1 rows only"""
ifconnection.thinorclient_version>=21:
for (j,) incursor.execute(sql):
print(j)
else:
for (j,) incursor.execute(sql):
print(json.loads(j.read()))

# Using JSON_OBJECT to extract relational data as JSON

sql="""select json_object('key' is d.dummy) dummy
 from dual d"""
forrincursor.execute(sql):
print(r)

# Using JSON_ARRAYAGG to extract a whole relational table as JSON

oracledb.defaults.fetch_lobs=False
sql="""select json_arrayagg(
 json_object('key' is c.id,
 'name' is c.json_data)
 returning clob)
 from CustomersAsJson c"""
forrincursor.execute(sql):
print(r)