Package org.sqlproc.engine

The package org.sqlproc.engine contains the public part of SQL Processor implementation.

See:
Description

Interface Summary

SqlFeature	Optional features, which can be activated in the process of SQL Processor initialization.
SqlMonitor	The vehicle interface definition, which can be used to monitor the duration of all SQL queries execution.
SqlMonitor.Runner	This interface is implemented in SqlEngine main public methods.
SqlMonitorFactory	The factory definition, which can be used to construct SqlMonitor.

Class Summary

SqlEngine	The primary SQL Processor class for the META SQL query execution.
SqlEngineLoader	Helper class for the parsing of META SQL statements and Mapping rules located in properties file.
SqlOrder	The list of ordering directives for the SQL Processor queries execution.
SqlPropertiesLoader	Helper class for the properties file loading.

Enum Summary

SqlOrder.Order

The enumeration for the ordering directives.

Exception Summary

SqlEngineException

General exception class for the SQL Processor parser.

Package org.sqlproc.engine Description

The package org.sqlproc.engine contains the public part of SQL Processor implementation. The most important class is SqlEngine. There are also some helper classes and basic interfaces.

SQL Processor is Data Driven Query Engine. It's able to dynamically generate ANSI SQL query based on search data provided by the user or the application. This is done in the runtime, without any plumbing code required.

In other words - SQL Processor has 3 basic inputs:

• A META SQL, an ANSI SQL extension based on ANTLR grammar. For example it can be select p.ID id, p.NAME name from PERSON p where 1=1 {& id=:id} {& UPPER(name)=:+name}
• Input values provided by the user. These data are collected in a search form, a standard POJO object, which can by created in presentation layer of a web application.
• A result class definition, which is used to carry output data from a SQL query execution. This class is a standard POJO object, instances of which are created in SQL Processor without any plumbing code. It can work as a transport object from persistence to presentation layer of a web application.

Next, SQL Processor has one output - the list of instances of result class.

For the META SQL described above the generated ANSI SQL can be

• select p.ID id, p.NAME name from PERSON p where 1=1 in the case there are no values in a search form
• select p.ID id, p.NAME name from PERSON p where 1=1 and id=? in the case there's a not null id attribute in a search form

In the process of data collection from a search form it's used Reflection API. The same is used in the process of seeding instances of result class with SQL query execution output.

The package org.sqlproc.engine.impl contains non public part of SQL Processor implementation, without any Javadoc. This is because the implementation can be changed any time to improve SQL Processor capabilities.

For more info please see the User's tutorial.

Author:

Vladimir Hudec