6.9.1.3 Dropping Property Graphs through DROP PROPERTY GRAPH Statements
You can use PGQL to drop property graphs. When a DROP PROPERTY
        GRAPH statement is called, all the property graph schema tables of the graph are
      dropped.
               
Example 6-5 PgqlDropExample1.java
This example shows how to drop a property graph.
import java.sql.Connection;
import oracle.pg.rdbms.pgql.PgqlConnection;
import oracle.pg.rdbms.pgql.PgqlStatement;
import oracle.ucp.jdbc.PoolDataSourceFactory;
import oracle.ucp.jdbc.PoolDataSource;
/**
 * This example shows how to drop a Property executing a PGQL drop statement.
 */
public class PgqlDropExample1
{
  public static void main(String[] args) throws Exception
  {
    int idx=0;
    String host               = args[idx++]; 
    String port               = args[idx++]; 
    String sid                = args[idx++]; 
    String user               = args[idx++]; 
    String password           = args[idx++];
    String graph              = args[idx++];
    Connection conn = null;
    PgqlStatement pgqlStmt = null;
    try {
      //Get a jdbc connection
      PoolDataSource  pds = PoolDataSourceFactory.getPoolDataSource();
      pds.setConnectionFactoryClassName("oracle.jdbc.pool.OracleDataSource");
      pds.setURL("jdbc:oracle:thin:@"+host+":"+port +":"+sid);
      pds.setUser(user);
      pds.setPassword(password);     
      conn = pds.getConnection();
      conn.setAutoCommit(false);
      // Get a PGQL connection
      PgqlConnection pgqlConn = PgqlConnection.getConnection(conn);
      // Create a PgqlStatement
      pgqlStmt = pgqlConn.createStatement();
      // Execute PGQL to drop property graph
      String pgql = "Drop Property Graph " + graph;
      pgqlStmt.execute(pgql);
    }
    finally {
      // close the statement
      if (pgqlStmt != null) {
        pgqlStmt.close();
      }
      // close the connection
      if (conn != null) {
        conn.close();
      }
    }
  }
}