In client-server configurations, the performance of a database application depends essentially on the number of client-server interactions.
The number of these interactions can be drastically reduced if a major proportion of SQL statements, which in well-structured programs are concentrated in an access layer, are executed in the server.
SQL-PL is the procedural SQL extension of the database system ADABAS for creating database procedures and triggers (in the following referred to as DB procedures and triggers respectively or generically as stored procedures).
Database procedures are SQL-PL procedures that are executed by the server. From the perspective of the application developer, a database procedure is treated like an SQL statement. Triggers, by contrast, are not called explicitly from an application program, but implicitly at the end of an INSERT, UPDATE or DELETE statement.
DB procedures serve to:
- reduce the interactions between client and server.
- centrally describe and centrally administer the application objects in the form of abstract data types.
- extend the facilities of the database in a customized way.
By means of triggers it is possible to:
- test complicated integrity rules.
- start derived database modifications for the current or any other row.
- implement complicated rules to protect against unauthorized access.
The SQL-PL workbench supports the development of stored procedures by means of a comfortable user interface with integrated version management.
In addition, SQL-PL offers an ideal test environment for DB procedures and triggers with the component FORM and an integrated debugger.
The SQL-PL language offers the following facilities:
- the standard functions
- the entire SQL language
- the integrated report generator
- the possibility of calling stored commands of QUERY
- an integrated editor
- the possibility of calling any arbitrary system editor
- a program generator for generating EASY-like programs
- the integrated data dictionary tool DOMAIN
There are various ways of calling an SQL-PL program:
- from the SQL-PL workbench
- directly from the operating system
- from a precompiled program
This manual describes the operation by means of the SQL-PL workbench. The call syntax for calling from the operating system is contained in the platform-specific user manual. Likewise, the call syntax for calling from precompiled programs can be found in the appropriate manual.