This article gives an overview of the Simple Oracle Document Access (SODA) for PL/SQL functionality in Oracle Database 18c.
◉ Create a Test Database User
We need a new database user for our testing.
CONN / AS SYSDBA
ALTER SESSION SET CONTAINER=pdb1;
DROP USER sodauser CASCADE;
CREATE USER sodauser IDENTIFIED BY sodauser1
DEFAULT TABLESPACE users QUOTA UNLIMITED ON users;
GRANT CREATE SESSION, CREATE TABLE TO sodauser;
GRANT SODA_APP TO sodauser;
Notice the grant for the SODA_APP role.
◉ Enable ORDS and SODA
We don't need to enable ORDS for the schema to use SODA for PL/SQL, but it makes sense to do this as it will allow the collection to be accessible from SODA for REST also.
Enable REST web services for the test schema. We could use any unique and legal URL mapping pattern for the schema, so it is not necessary to expose the schema name as we have done here.
CONN sodauser/sodauser1@pdb1
BEGIN
ORDS.enable_schema(
p_enabled => TRUE,
p_schema => 'SODAUSER',
p_url_mapping_type => 'BASE_PATH',
p_url_mapping_pattern => 'sodauser',
p_auto_rest_auth => FALSE
);
COMMIT;
END;
/
We are now ready to start.
◉ Collections
As the name suggests, collections are a way of grouping documents. It probably makes sense to define separate collections for different types of documents, but there is nothing to stop you keeping a variety of document types in a single collection.
- Check Collection Exists
We can check if a collection exists by attempting to open it. If the DBMS_SODA.OPEN_COLLECTION function returns a NULL, we know the collection doesn't exist. If the collection does exist, a reference to it will be returned as the SODA_COLLECTION_T type.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
IF l_collection IS NOT NULL THEN
DBMS_OUTPUT.put_line('collection: ' || l_collection.get_name());
ELSE
DBMS_OUTPUT.put_line('Collection does not exist.');
END IF;
END;
/
Collection does not exist.
PL/SQL procedure successfully completed.
SQL>
- Create a Collection
The DBMS_SODA.CREATE_COLLECTION function creates a new collection and returns the collection reference as the SODA_COLLECTION_T type.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
BEGIN
l_collection := DBMS_SODA.create_collection('TestCollection1');
IF l_collection IS NOT NULL THEN
DBMS_OUTPUT.put_line('Collection ID : ' || l_collection.get_name());
ELSE
DBMS_OUTPUT.put_line('Collection does not exist.');
END IF;
END;
/
collection: TestCollection1
PL/SQL procedure successfully completed.
SQL>
The table has been created in the test schema. The table name is case sensitive, so you will have to double-quote the table name.
DESC "TestCollection1"
Name Null? Type
--------------------------------------- -------- ------------------------------------
ID NOT NULL VARCHAR2(255)
CREATED_ON NOT NULL TIMESTAMP(6)
LAST_MODIFIED NOT NULL TIMESTAMP(6)
VERSION NOT NULL VARCHAR2(255)
JSON_DOCUMENT BLOB
SQL>
This is essentially a table holding key-value pairs, with the key being the ID column and the value being the JSON_DOCUMENT column.
- List All Collections
The DBMS_SODA.LIST_COLLECTION_NAMES function returns a list the available collections as the SODA_COLLNAME_LIST_T type.
SET SERVEROUTPUT ON
DECLARE
l_coll_list SODA_COLLNAME_LIST_T;
BEGIN
l_coll_list := DBMS_SODA.list_collection_names;
IF l_coll_list.COUNT > 0 THEN
FOR i IN 1 .. l_coll_list.COUNT LOOP
DBMS_OUTPUT.put_line(i || ' : ' || l_coll_list(i));
END LOOP;
END IF;
END;
/
1 : TestCollection1
PL/SQL procedure successfully completed.
SQL>
- Drop a Collection
The DBMS_SODA.DROP_COLLECTION function drops the specified collection and returns "1" if it is successful, or "0" if it fails.
SET SERVEROUTOUT ON
DECLARE
l_status NUMBER := 0;
BEGIN
l_status := DBMS_SODA.drop_collection('TestCollection1');
DBMS_OUTPUT.put_line('status : ' || l_status);
END;
/
status : 1
PL/SQL procedure successfully completed.
SQL>
The table has been removed from the schema.
DESC "TestCollection1"
ERROR:
ORA-04043: object "TestCollection1" does not exist
SQL>
The remaining examples assume the "TestCollection1" collection is present, so if you deleted it previously, recreate it.
◉ Documents
A document is a combination of a JSON document you wish to persist in a collection, along with some document metadata, including a document identifier/key (ID). The document key can be assigned manually, or automatically is the key presented is null.
- Create a Document
A new document is created using the SODA_DOCUMENT_T constructor. There are overloads to create documents from VARCHAR2, CLOB and BLOB content. The document key and media type are optional. If the key is not set manually, a system generated key is used once the document is inserted into a collection.
SET SERVEROUTPUT ON
DECLARE
l_varchar2_doc SODA_DOCUMENT_T;
l_clob_doc SODA_DOCUMENT_T;
l_blob_doc SODA_DOCUMENT_T;
BEGIN
DBMS_OUTPUT.put_line('==========');
DBMS_OUTPUT.put_line('Key and VARCHAR2 Content.');
l_varchar2_doc := SODA_DOCUMENT_T(
key => '1234',
v_content => '{"employee_number":7369,"employee_name":"SMITH"}'
);
DBMS_OUTPUT.put_line('key : ' || l_varchar2_doc.get_key);
DBMS_OUTPUT.put_line('content : ' || l_varchar2_doc.get_varchar2);
DBMS_OUTPUT.put_line('media_type: ' || l_varchar2_doc.get_media_type);
DBMS_OUTPUT.put_line('==========');
DBMS_OUTPUT.put_line('CLOB Content and Media Type.');
l_clob_doc := SODA_DOCUMENT_T(
c_content => '{"employee_number":7499,"employee_name":"ALLEN"}',
media_type => 'application/json'
);
DBMS_OUTPUT.put_line('key : ' || l_clob_doc.get_key);
DBMS_OUTPUT.put_line('content : ' || l_clob_doc.get_clob);
DBMS_OUTPUT.put_line('media_type: ' || l_clob_doc.get_media_type);
DBMS_OUTPUT.put_line('==========');
DBMS_OUTPUT.put_line('BLOB Content.');
l_blob_doc := SODA_DOCUMENT_T(
b_content => UTL_RAW.cast_to_raw('{"employee_number":7521,"employee_name":"WARD"}')
);
DBMS_OUTPUT.put_line('key : ' || l_blob_doc.get_key);
DBMS_OUTPUT.put_line('content : ' || UTL_RAW.cast_to_varchar2(l_blob_doc.get_blob));
DBMS_OUTPUT.put_line('media_type: ' || l_blob_doc.get_media_type);
END;
/
==========
Key and VARCHAR2 Content.
key : 1234
content : {"employee_number":7369,"employee_name":"SMITH"}
media_type: application/json
==========
CLOB Content and Media Type.
key :
content : {"employee_number":7499,"employee_name":"ALLEN"}
media_type: application/json
==========
BLOB Content.
key :
content : {"employee_number":7521,"employee_name":"WARD"}
media_type: application/json
PL/SQL procedure successfully completed.
SQL>
Notice the KEY is null unless it is specified manually. A unique system generated key will be assigned once the document is inserted into a collection.
- Insert a Document
A new document is added to the collection using the INSERT_ONE or INSERT_ONE_AND_GET member functions of the SODA_COLLECTION_T type. If you don't care about retrieving a system generated key use the INSERT_ONE member function.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_document SODA_DOCUMENT_T;
l_status NUMBER;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_document := SODA_DOCUMENT_T(
b_content => UTL_RAW.cast_to_raw('{"employee_number":7521,"employee_name":"WARD"}')
);
l_status := l_collection.insert_one(l_document);
DBMS_OUTPUT.put_line('status : ' || l_status);
COMMIT;
END;
/
status : 1
PL/SQL procedure successfully completed.
SQL>
If you need to retrieve the system generated key you should use INSERT_ONE_AND_GET member function.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_document SODA_DOCUMENT_T;
l_document_out SODA_DOCUMENT_T;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_document := SODA_DOCUMENT_T(
b_content => UTL_RAW.cast_to_raw('{"employee_number":7521,"employee_name":"WARD"}')
);
l_document_out := l_collection.insert_one_and_get(l_document);
DBMS_OUTPUT.put_line('key : ' || l_document_out.get_key);
DBMS_OUTPUT.put_line('content : ' || UTL_RAW.cast_to_varchar2(l_document_out.get_blob));
DBMS_OUTPUT.put_line('media_type: ' || l_document_out.get_media_type);
COMMIT;
END;
/
key : 6D9566A935014FE7BF1D0630B7E44313
content :
media_type: application/json
PL/SQL procedure successfully completed.
SQL>
Notice the document content is not present in the document returned by the INSERT_ONE_AND_GET function. This is intentional, as it would represent a waste of resources if we were dealing with large document.
We can see rows containing the documents have been added to the associated table.
SELECT COUNT(*) FROM "TestCollection1";
COUNT(*)
----------
2
SQL>
- Retrieve Documents
You retrieve a document using the FIND_ONE member function of the SODA_COLLECTION_T type.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_document SODA_DOCUMENT_T;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_document := l_collection.find_one('6D9566A935014FE7BF1D0630B7E44313');
DBMS_OUTPUT.put_line('key : ' || l_document.get_key);
DBMS_OUTPUT.put_line('content : ' || UTL_RAW.cast_to_varchar2(l_document.get_blob));
DBMS_OUTPUT.put_line('media_type: ' || l_document.get_media_type);
COMMIT;
END;
/
key : 6D9566A935014FE7BF1D0630B7E44313
content : {"employee_number":7521,"employee_name":"WARD"}
media_type: application/json
PL/SQL procedure successfully completed.
SQL>
- Update a Document
An existing document in the collection is updated using the REPLACE_ONE or REPLACE_ONE_AND_GET member functions of the SODA_COLLECTION_T type. The REPLACE_ONE member function returns "1" if the replace is successful and "0" if isn't.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_document SODA_DOCUMENT_T;
l_status NUMBER;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_document := SODA_DOCUMENT_T(
b_content => UTL_RAW.cast_to_raw('{"employee_number":7499,"employee_name":"ALLEN"}')
);
l_status := l_collection.replace_one('6D9566A935014FE7BF1D0630B7E44313', l_document);
DBMS_OUTPUT.put_line('status : ' || l_status);
COMMIT;
END;
/
status : 1
PL/SQL procedure successfully completed.
SQL>
The REPLACE_ONE_AND_GET member function is similar to the INSERT_ONE_AND_GET member function, in that it returns a document minus the content.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_document SODA_DOCUMENT_T;
l_document_out SODA_DOCUMENT_T;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_document := SODA_DOCUMENT_T(
b_content => UTL_RAW.cast_to_raw('{"employee_number":7499,"employee_name":"ALLEN"}')
);
l_document_out := l_collection.replace_one_and_get('6D9566A935014FE7BF1D0630B7E44313', l_document);
DBMS_OUTPUT.put_line('key : ' || l_document_out.get_key);
DBMS_OUTPUT.put_line('content : ' || UTL_RAW.cast_to_varchar2(l_document_out.get_blob));
DBMS_OUTPUT.put_line('media_type: ' || l_document_out.get_media_type);
COMMIT;
END;
/
key : 6D9566A935014FE7BF1D0630B7E44313
content :
media_type: application/json
PL/SQL procedure successfully completed.
SQL>
- Delete a Document
An existing document in the collection is removed using the REMOVE_ONE member function of the SODA_COLLECTION_T type.
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_status NUMBER;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection1');
l_status := l_collection.remove_one('6D9566A935014FE7BF1D0630B7E44313');
DBMS_OUTPUT.put_line('status : ' || l_status);
COMMIT;
END;
/
status : 1
PL/SQL procedure successfully completed.
SQL>
◉ Custom Collections
By default collections have a BLOB payload and the IDs are handled automatically. Srikrishnan Suresh pointed out this default behaviour can be modified by specifying metadata for the collection. The following CREATE_COLLECTION call includes the metadata to allow the key column to be set manually, and alters the document data type to a CLOB data type.
DECLARE
l_collection SODA_COLLECTION_T;
l_metadata VARCHAR2(32767);
BEGIN
l_metadata := '{
"keyColumn":{
"assignmentMethod": "CLIENT"
},
"contentColumn": {
"sqlType": "CLOB"
}
}';
l_collection := DBMS_SODA.create_collection('TestCollection2', l_metadata);
IF l_collection IS NOT NULL THEN
DBMS_OUTPUT.put_line('Collection ID : ' || l_collection.get_name());
ELSE
DBMS_OUTPUT.put_line('Collection does not exist.');
END IF;
END;
/
Collection ID : TestCollection2
PL/SQL procedure successfully completed.
SQL>
The associated table structure looks different now, matching the metadata.
SQL> desc "TestCollection2"
Name Null? Type
---------------------------------- -------- ----------------------------
ID NOT NULL VARCHAR2(255)
JSON_DOCUMENT CLOB
SQL>
SET SERVEROUTPUT ON
DECLARE
l_collection SODA_COLLECTION_T;
l_clob_doc SODA_DOCUMENT_T;
l_document_out SODA_DOCUMENT_T;
BEGIN
l_collection := DBMS_SODA.open_collection('TestCollection2');
l_clob_doc := SODA_DOCUMENT_T(
key => '1234',
c_content => '{"employee_number":7499,"employee_name":"ALLEN"}',
media_type => 'application/json'
);
l_document_out := l_collection.insert_one_and_get(l_clob_doc);
DBMS_OUTPUT.put_line('key : ' || l_document_out.get_key);
DBMS_OUTPUT.put_line('content : ' || l_document_out.get_clob);
DBMS_OUTPUT.put_line('media_type: ' || l_document_out.get_media_type);
COMMIT;
END;
/
key : 1234
content :
media_type: application/json
PL/SQL procedure successfully completed.
SQL>
We can drop the collection in the normal way.
SET SERVEROUTOUT ON
DECLARE
l_status NUMBER := 0;
BEGIN
l_status := DBMS_SODA.drop_collection('TestCollection2');
DBMS_OUTPUT.put_line('status : ' || l_status);
END;
/
status : 1
PL/SQL procedure successfully completed.
SQL>
Source: oracle-base.com
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