Db cursor updating in same table oracle radio active dating
Without DRCP, a Python connection must start and terminate a server process. Batch scripts doing long running jobs should generally use non-pooled connections.
This tutorial shows how DRCP can be used by new or existing applications without writing or changing any application logic.
Bind variables improve code reusability, and can reduce the risk of SQL Injection attacks. The second argument to the execute() call is a Python Dictionary. The commit call is commented out, and does not execute. def DCNCallback(message): print "Notification:" for tab in message.tables: print "Table:", for row in tab.rows: if row.operation & cx_Oracle.
To use bind variables in this example, perform the following steps. In the first execute call, this associative array has the value 210 for the key of "id". The final part of the script queries the results back and displays them as a list of tuples. The two PL/SQL function parameters are passed as a tuple and bound to the function parameter arguments. OPCODE_INSERT: print "INSERT of rowid:", row.rowid if row.operation & cx_Oracle.
The remove("2") method deletes an element from the list. Other datatypes Python has are Dictionaries, which are associative arrays, and a type called a tuple, which is like a list but cannot be changed. It is useful for short lived scripts such as typically used by web applications.
The connection class tells the database server pool that connections are related. This reduces the number of "roundtrips" made to the database, often reducing networks load and reducing the number of context switches on the database server.
Session information (such as the default date format) might be retained between connection calls, giving performance benefits. The fetchone(), fetchmany() and even fetchall() methods will read from the cache before requesting more data from the database.
For this Hands On Session, the following has already been installed for you: method is passed the username "pythonhol", the password "welcome" and the connection string.
In this case, Oracle's Easy Connect connection string syntax is used.
Session information will be discarded if a pooled server is later reused by an application with a different connection class name. From a terminal window, run: Rerun the script a few times and compare the performance of the two arraysize settings.