Accessing the Database

The following figure illustrates how applications communicate to the database:

Libpq is the POSTGRESQL C library that allows applications to communicate with the database. Using libpq is a fairly straightforward process:

• Call a libpq function to connect to the database
• Receive a connection handle (PGconn)
• Issue a query
  • Use the connection handle to issue a query
  • Receive a result handle (PGresult)
  • Access the result
• Issue more queries if desired
• Close the database connection