Database Connection Objects

The new implementation introduces database connection objects as containers for parameters describing SQL connections to the database.

Users can execute SQL queries via DB connection objects and return either disconnected SCADA recordsets or the connected SCADA recordset holding results of the queries.

Disconnected SCADA recordsets have no direct association to their DB connection objects and their lifetime is not limited by the DB connection objects’ lifetime. They should be closed in Cicode when no longer necessary.

The connected SCADA recordset is directly associated to the DB connection object. The relation is 1-1 and there cannot be more than one connected recordset per one connection. The associated connected recordset is called further a default recordset.

SQL functions from the previous SCADA are kept and their functionality, from a user’s point of view, is the same as before (see Cicode functions for minor exceptions).

A set of new Cicode SQL functions is introduced together with the new ADO interface. These new functions can be divided into four categories:

• Creation/connection – functions servicing separate creation of DB connection objects and separate connection initialization

• Multiple recordsets per connection – functions enabling users to obtain and use handles to disconnected recordsets (the old database access methods limited the number of recordsets per connection to one)

• Parameterization – functions helping to provide more secure way of building SQL queries

• Multiple queries per connection – functions enabling users to obtain and use handles to queries (the old database access methods limited the number of queries per connection to 1)

See Also

Basic SQL Scenarios