6.9.1.5.3 Basic Query Execution

You can execute PGQL queries using the opg4py.pgql Python wrapper.

Executing PGQL Queries Using the Python Client

• Set the graph for querying as shown:

  >>> pgql_conn.set_graph("<graph_name>")
  

  where <graph_name> is the name of the graph.

• Define and execute the PGQL SELECT query. For example,

  >>> pgql = "SELECT e.from_acct_id, e.to_acct_id, e.amount FROM MATCH (n:accounts) -[e:transfers]-> (m:accounts) on bank_graph limit 10"
  

• Execute and print the result set as shown:

  >>> pgql_result_set = pgql_statement.execute_query(pgql)
  >>> pgql_result_set.print()
  +------------------------------------+
  | FROM_ACCT_ID | TO_ACCT_ID | AMOUNT |
  +------------------------------------+
  | 781.0        | 712.0      | 1000.0 |
  | 190.0        | 555.0      | 1000.0 |
  | 191.0        | 329.0      | 1000.0 |
  | 198.0        | 57.0       | 1000.0 |
  | 220.0        | 441.0      | 1000.0 |
  | 251.0        | 387.0      | 1000.0 |
  | 254.0        | 188.0      | 1000.0 |
  | 259.0        | 305.0      | 1000.0 |
  | 261.0        | 145.0      | 1000.0 |
  | 263.0        | 40.0       | 1000.0 |
  +------------------------------------+
  
  PgqlResultSet(java_pgql_result_set: oracle.pg.rdbms.pgql.PgqlResultSet, # of results: 0)
  
  

Also, you can convert the PGQL result set obtained in the preceding code to a Pandas dataframe using the to_pandas() method.

Note:

The pandas package must be installed in your system to successfully execute the call to to_pandas(). This package is automatically installed at the time of the Python client installation. However, if your call to to_pandas() fails, verify if the pandas module is installed in your system. In case the module is found missing, then install the pandas package manually.