System API

Supported Databases

UnityJDBC supports any JDBC-accessible data source including full-featured databases such as Oracle, Microsoft SQL Server, PostgreSQL, MySQL, Sybase, and IBM DB2 as well as text-based sources, generic JDBC/ODBC sources, and NoSQL sources such as MongoDB and Cassandra. Each data source has a different SQL dialect and supports certain functions. Data sources without their own database id inherit features from the SQL99 standard dialect (id=99) and the Common SQL functions dialect (id=1000). A dialect may inherit the features of another dialect then modify or add its own features.

A database identifier is specified in the databaseId tag of the schema file to identify the source dialect. The dialect can also be set in code using the following statements:

SourceDatabase db = con.getDatabase("OrderDB");   // Retrieve the database called OrderDB
db.setDatabaseId(10100000);                       // Set database dialect for Microsoft SQL Server 2008

Click to see a list of supported database identifiers

Functions and Function Translation

UnityJDBC automatically translates functions and SQL syntax to the appropriate SQL dialect for the underlying database. Functions are renamed and parameters are re-ordered as required. If a function is not supported by the database, it is executed automatically inside UnityJDBC. Each database system is assigned a database identifier that is specified in the schema file describing the source. The database id allows UnityJDBC to determine which functions are supported on the database and the appropriate mappings.

Function Categories

• Aggregate Functions
• Bit-wise Functions
• Date and Time Functions
• Mathematical Functions
• String Functions
• Syntax Features
• System Functions