This section provides some examples:

• Turn On PGQL Mode
• Create a Property Graph and Execute a Query
• Define a Graph Parameter
• Show SQL Translation Using Parallel Value 2
• Turn Off PGQL Mode

Turn On PGQL Mode

This example turns PGQL mode on. The PGQL prompt appears when PGQL is enabled.

SQL> pgql auto on;
  
PGQL Auto enabled for graph=[null], execute=[true], translate=[false]
PGQL>

Create a Property Graph and Execute a Query

This example creates a property graph and executes a query against the newly created "scott_hr" graph.

PGQL> CREATE PROPERTY GRAPH scott_hr
  2    VERTEX TABLES (
  3      emp KEY(empno) LABEL Employee
  4        PROPERTIES ARE ALL COLUMNS EXCEPT ( deptno ),
  5      dept KEY(deptno) LABEL Department
  6        PROPERTIES ( deptno, dname )
  7    )
  8    EDGE TABLES (
  9      emp AS works_for
 10         KEY(empno) 
 11        SOURCE KEY ( empno ) REFERENCES emp
 12        DESTINATION KEY ( deptno ) REFERENCES dept
 13        NO PROPERTIES
 14    )
 15    OPTIONS(PG_PGQL);
  
Graph created
  
PGQL> column name format a15;
PGQL> SELECT e.ename AS name
  2  FROM MATCH (e:Employee) ON scott_hr
  3  ORDER by e.ename
  4  LIMIT 4;
 
NAME          
---------------
ADAMS         
ALLEN         
BLAKE         
CLARK

Define a Graph Parameter

You can define a graph parameter to run all PGQL queries against a particular graph. This example sets graph to scott_hr. Note that the query does not need an ON clause.

PGQL> pgql auto on graph scott_hr;
 
PGQL Auto enabled for graph=[SCOTT_HR], execute=[true], translate=[false]
 
PGQL> column department format a20;
PGQL> column employees format a10;
PGQL> SELECT d.dname AS department, COUNT(e) AS employees
  2  FROM MATCH (e:Employee) -[:works_for]-> (d:Department)
  3  GROUP BY d
  4  ORDER BY employees
  5* LIMIT 3;
 
DEPARTMENT           EMPLOYEES
-------------------- ----------
ACCOUNTING           3        
RESEARCH             5        
SALES                6

Show SQL Translation Using Parallel Value 2

This example shows the SQL translation of a PGQL query using a parallel value of 2. Note that the SQL translation has a hint using the defined parallel value.

SQL> pgql auto on translateonly parallel 2;
 
PGQL Auto enabled for graph=[null], execute=[false], translate=[true]
PGQL> SELECT id(n) FROM MATCH (n) ON scott_hr;
SELECT /*+ parallel(2) */ * FROM(SELECT 7 AS "id(n)$T",
to_nchar(T0$0.VID,'TM9','NLS_Numeric_Characters=''.,''') AS "id(n)$V",
T0$0.VID AS "id(n)$VN",
to_timestamp_tz(null) AS "id(n)$VT"
FROM "SCOTT".SCOTT_HRVD$ T0$0);

Turn Off PGQL Mode

This example shows how to turn PGQL mode off.

PGQL> pgql auto off;
  
PGQL Auto disabled
SQL>