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Oracle 11g uses ords+pljson to implement JSON_ Table effect

2022-07-02 07:11:00 【Virtuous time】

Oracle stay 12.1 Introduced the right json Support for , You can use sql To query json The value of each node of the field , about 11G Version of , for example EBS Environmental Science , It is not convenient to upgrade to 12C, Open source software can be used pljson To achieve , This article uses ORDS + pljson To develop a post Sample request , Receive order data .

Involving software components

ORDS 20.2
pljson 3.5.2
Oracle dbms 11GR2
Oracle apex 20.1

json Data source instance

The following paragraph is to deal with json, It is a multi-level organization , Including order header information and two order lines 

{
    
	"PONumber": 1608,
	"Requestor": "Alexis Bull",
	"CostCenter": "A50",
	"Address": {
    
		"street": "200 Sporting Green",
		"city": "South San Francisco",
		"state": "CA",
		"zipCode": 99236,
		"country": "United States of America"
	},
	"LineItems": [
		{
    
			"ItemNumber": 1,
			"Part": {
    
				"Description": "One Magic Christmas",
				"UnitPrice": 19.95,
				"UPCCode": 1313109289
			},
			"Quantity": 9.0
		},
		{
    
			"ItemNumber": 2,
			"Part": {
    
				"Description": "Lethal Weapon",
				"UnitPrice": 19.95,
				"UPCCode": 8539162892
			},
			"Quantity": 5.0
		}
	]
}

Data source reference document

Technical realization

Above Oracle In official documents , Used json_table function , The sum of this function 11G Of xmltable The functional grammar style is very similar , This is 12C Then there is a new function , For processing json String is very convenient , But for 12.1 The previous version does not have this function ,Oracle Always slow down , stay 12C Before, everyone was right about json The demand is relatively strong , So there are open source tools pljson, This plug-in is essentially right Oracle Some applications of sets .
But open source is not as easy to use as native ones implemented from the bottom , For example, there is a query function such as the following code ：

select *
from table(
pljson_table.json_table(
'{"data": { "name": "name 3", "description": "blah blah...", "type": "text", "created_time": "2015-12-21T19:23:29+0000", "shares": { "count": 100 }, "extra": null, "maps" : [ true, true, false ] } }',
pljson_varray('data.name', 'data.extra', 'data.maps', 'data.shares.count', 'data.missing'),
pljson_varray('name', 'extra', 'map', 'count', 'whatelse'))
)

As a sql Script in sql There is no problem when running in the engine , But in pl/sql An error will be reported under the engine ORA-22905 Cannot access rows from non nested table entries , The essence is to use table I need to be in pl/sql Block to declare table What type is it inside . however pljson_table.json_table The return value of anydataset, This Oracle ANYDATASET type There is another way to play , Don't study how to realize in pl/sql This is used inside . Change your mind , We can encapsulate the above query into a view , View is used sql engine , And then in pl/sql Just query this view .

Official code

Essentially, we want to achieve the following effects , The following code is from Oracle official ORDS file .

Declare
  L_PO     BLOB;
 
Begin
  L_PO := :body;
 
INSERT INTO PurchaseOrder
      SELECT * FROM json_table(L_PO  FORMAT JSON, '$'
         COLUMNS (
           PONo            Number    PATH '$.PONumber',
           Requestor       VARCHAR2  PATH '$.Requestor',
           CostCenter      VARCHAR2  PATH '$.CostCenter',
           AddressStreet   VARCHAR2  PATH '$.Address.street',
           AddressCity     VARCHAR2  PATH '$.Address.city',
           AddressState    VARCHAR2  PATH '$.Address.state',
           AddressZip      VARCHAR2  PATH '$.Address.zipCode',
           AddressCountry  VARCHAR2  PATH '$.Address.country'));
 
INSERT INTO LineItem 
SELECT * FROM json_table(L_PO  FORMAT JSON, '$'
         COLUMNS (
           PONo  Number PATH '$.PONumber',
           NESTED             PATH '$.LineItems[*]'
             COLUMNS (
               ItemNumber        Number   PATH '$.ItemNumber',
               PartDescription   VARCHAR2   PATH '$.Part.Description',
               PartUnitPrice     Number   PATH '$.Part.UnitPrice',
               PartUPCCode       Number   PATH '$.Part.UPCCode',
               Quantity          Number   PATH '$.Quantity')));
commit;
end;

json_table(L_PO FORMAT JSON It's powerful , A lot of things have been achieved at one time ,blob To clob Transformation , Definition of set .

Therefore, we need to realize it by ourselves blob To clob transformation , because pljson The input parameter received must be clob type .

Table structure

The table structure is as follows ：

-- receive POST Come over to the table of raw data 
-- Create table
create table CUX_APEX_JSON_CLOB_DATA
(
  request_id    NUMBER not null,
  json_lob      CLOB,
  creation_date DATE default SYSDATE
);
-- Create/Recreate indexes 
create unique index CUX_APEX_JSON_CLOB_DATA_U1 on CUX_APEX_JSON_CLOB_DATA (REQUEST_ID);
-- Sequence 
create sequence CUX_APEX_JSON_CLOB_DATA_S;

-- Create table  Order header table 
create table PURCHASEORDER
(
  pono           NUMBER(5) not null,
  requestor      VARCHAR2(50),
  costcenter     VARCHAR2(5),
  addressstreet  VARCHAR2(50),
  addresscity    VARCHAR2(50),
  addressstate   VARCHAR2(2),
  addresszip     VARCHAR2(10),
  addresscountry VARCHAR2(50),
  request_id     NUMBER not null
);
-- Create/Recreate primary, unique and foreign key constraints 
alter table PURCHASEORDER
  add primary key (PONO)
  ;

-- Create table  Order line table 
create table LINEITEM
(
  pono            NUMBER(5) not null,
  itemnumber      NUMBER(10) not null,
  partdescription VARCHAR2(50),
  partunitprice   NUMBER(10),
  partupccode     NUMBER(10),
  quantity        NUMBER(10),
  qequest_id      NUMBER not null
);
-- Create/Recreate primary, unique and foreign key constraints 
alter table LINEITEM
  add primary key (PONO, ITEMNUMBER);

bloc_to_clob Conversion function 

CREATE OR REPLACE FUNCTION blob_to_clob(blob_in IN BLOB) RETURN CLOB AS
    v_clob    CLOB;
    v_varchar VARCHAR2(32767);
    v_start   PLS_INTEGER := 1;
    v_buffer  PLS_INTEGER := 32767;
BEGIN
    DBMS_LOB.CREATETEMPORARY(v_clob, TRUE);
    FOR i IN 1 .. CEIL(DBMS_LOB.GETLENGTH(blob_in) / v_buffer) LOOP
        v_varchar := UTL_RAW.CAST_TO_VARCHAR2(DBMS_LOB.SUBSTR(blob_in,
                                                              v_buffer,
                                                              v_start));
        DBMS_LOB.WRITEAPPEND(v_clob, LENGTH(v_varchar), v_varchar);
        --DBMS_OUTPUT.PUT_LINE(v_varchar);
        v_start := v_start + v_buffer;
    END LOOP;
    RETURN v_clob;
END blob_to_clob;

View 

-------------------- We need to pay attention to , View select Fields must be capitalized ----------------------------------
-- Header table view 
CREATE OR REPLACE VIEW DEMO_HEADER_V AS
SELECT js."PONO",
       js."REQUESTOR",
       js."COSTCENTER",
       js."ADDRESSSTREET",
       js."ADDRESSCITY",
       js."ADDRESSSTATE",
       js."ADDRESSZIP",
       js."ADDRESSCOUNTRY",
       tab.request_id
  FROM cux_apex_json_clob_data tab,
       TABLE(pljson_table.json_table(tab.json_lob,
                                     pljson_varray('PONumber',
                                                   'Requestor',
                                                   'CostCenter',
                                                   'Address.street',
                                                   'Address.city',
                                                   'Address.state',
                                                   'Address.zipCode',
                                                   'Address.country'),
                                     pljson_varray('pono',
                                                   'requestor',
                                                   'costcenter',
                                                   'addressstreet',
                                                   'addresscity',
                                                   'addressstate',
                                                   'addresszip',
                                                   'addresscountry'))) js;

-- Row table view 
CREATE OR REPLACE VIEW DEMO_LINE_V AS
SELECT js."PONO",
       js."ITEMNUMBER",
       js."PARTDESCRIPTION",
       js."PARTUNITPRICE",
       js."PARTUPCCODE",
       js."QUANTITY",
       pljtt.request_id
  FROM cux_apex_json_clob_data pljtt,
       TABLE(pljson_table.json_table(pljtt.json_lob,
                                     pljson_varray('PONumber',
                                                   'LineItems[*].ItemNumber',
                                                   'LineItems[*].Part.Description',
                                                   'LineItems[*].Part.UnitPrice',
                                                   'LineItems[*].Part.UPCCode',
                                                   'LineItems[*].Quantity'),
                                     pljson_varray('pono',
                                                   'itemnumber',
                                                   'partdescription',
                                                   'partunitprice',
                                                   'partupccode',
                                                   'quantity'),
                                     table_mode => 'nested')) js;

pl/sql Code 

CREATE OR REPLACE PACKAGE cux_apex_json_demo_pkg IS

   PROCEDURE create_order(p_body IN BLOB);

END cux_apex_json_demo_pkg;
/
CREATE OR REPLACE PACKAGE BODY cux_apex_json_demo_pkg IS

   --******************************************************************************
   -- FUNCTION get_tax_rate
   --
   -- p_body POST Please come here BLOB data 
   --
   -- Public. demo demonstration , obtain POST Over here json data , Put it in storage 
   --
   --******************************************************************************

   PROCEDURE create_order(p_body IN BLOB)
   
    IS
   
      c_body       CLOB := blob_to_clob(p_body);
      l_request_id NUMBER := cux_apex_json_clob_data_s.nextval;
   
   BEGIN
      INSERT INTO cux_apex_json_clob_data
      VALUES
         (l_request_id, c_body, SYSDATE);
      plog.debug(l_request_id || '-insert cux_apex_json_clob_data rows:' || SQL%ROWCOUNT);
   
      INSERT INTO PurchaseOrder
         SELECT *
           FROM demo_header_v
          WHERE request_id = l_request_id;
      plog.debug(l_request_id || '-insert PurchaseOrder rows:' || SQL%ROWCOUNT);
   
      INSERT INTO LineItem
         SELECT *
           FROM demo_line_v
          WHERE request_id = l_request_id;
      plog.debug(l_request_id || '-insert LineItem rows:' || SQL%ROWCOUNT);
   
      COMMIT;
   
   EXCEPTION
      WHEN OTHERS THEN
         plog.full_error_backtrace;
         RAISE;
   END create_order;

BEGIN
   NULL;
END cux_apex_json_demo_pkg;
/

Package to ORDS in 

BEGIN
  ORDS.ENABLE_SCHEMA(
      p_enabled             => TRUE,
      p_schema              => 'CUX_APEX',
      p_url_mapping_type    => 'BASE_PATH',
      p_url_mapping_pattern => 'CUX_APEX',
      p_auto_rest_auth      => FALSE);
    
  ORDS.DEFINE_MODULE(
      p_module_name    => 'demo',
      p_base_path      => '/demo/',
      p_items_per_page => 25,
      p_status         => 'PUBLISHED',
      p_comments       => 'json Multiline test ');

  ORDS.DEFINE_TEMPLATE(
      p_module_name    => 'demo',
      p_pattern        => 'test',
      p_priority       => 0,
      p_etag_type      => 'HASH',
      p_etag_query     => NULL,
      p_comments       => NULL);

  ORDS.DEFINE_HANDLER(
      p_module_name    => 'demo',
      p_pattern        => 'test',
      p_method         => 'POST',
      p_source_type    => 'plsql/block',
      p_items_per_page => 0,
      p_mimes_allowed  => '',
      p_comments       => NULL,
      p_source         => 
'BEGIN cux_apex_json_demo_pkg.create_order(:BODY); END; ');

    
        
COMMIT;

END;

stay aepx The following effects are defined in ：

Insert picture description here

Additional updates

The above example requires json Data warehousing , In fact, dynamic sql Words , Can be json Pass in as a binding variable , This avoids inserting redundant data , But the original transmission will be lost json data .

--json Content 

{
   "DATA":
[{
   "storeId":"1","supplierId":"111","takeCost":"1.00","takeDate":"20191112"},
{
   "storeId":"2","supplierId":"2","takeCost":"200.00","takeDate":"20191114"},
{
   "storeId":"2","supplierId":"3","takeCost":"100.00","takeDate":"20191111"}]
}

-- dynamic sql
execute immediate q'{ insert into supp_cost_t(storeid, supplierid, takecost, takedate) select b.storeid, b.supplierId, b.takeCost, b.takeDate from table(pljson_table.json_table(:1, pljson_varray('DATA[*].storeId', 'DATA[*].supplierId', 'DATA[*].takeCost', 'DATA[*].takeDate'), pljson_varray('storeId', 'supplierId', 'takeCost', 'takeDate'), table_mode => 'nested')) b}'
      using json_CLOB;

Reference blog ：
https://darkathena.blog.csdn.net/article/details/120644329?spm=1001.2014.3001.5502

原网站

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