EJB query language

An EJB query is a string that contains the following elements:

• a SELECT clause that specifies the enterprise beans or values to return;

• a FROM clause that names the bean collections;

• an optional WHERE clause that contains search predicates over the collections;

• an optional GROUP BY and HAVING clause (see Aggregation functions);

• an optional ORDER BY clause that specifies the ordering of the result collection.

The SELECT clause is optional in order to maintain compatibility with WebSphere Application Server V4.

Collections of entity beans are identified in EJB queries through the use of their abstract schema name in the query FROM clause.

The elements of EJB query language are discussed in more detail in the following related topics.

 

See also

Example: EJB queries
FROM clause
Inheritance in EJB query
Path expressions
WHERE clause
Scalar functions
Aggregation functions
SELECT clause
ORDER BY clause
Subqueries
EJB query compatibility issues with SQL
Database restrictions for EJB query
Rules for data type manipulation in EJB query
EJB query: Reserved words
EJB query: BNF syntax
Comparison of EJB 2.1 specification and WebSphere query language

 

Related Tasks

Using EJB query

 

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