WHERE clause

The WHERE clause lists search conditions for items to add to a result set.

The WHERE clause contains search conditions composed of the following:

• literal values

• input parameters

• expressions

• basic predicates

• quantified predicates

• BETWEEN predicate

• IN predicate

• LIKE predicate

• NULL predicate

• EMPTY collection predicate

• MEMBER OF predicate

• EXISTS predicate

• IS OF TYPE predicate

If the search condition evaluates to TRUE, the tuple is added to the result set.

Subtopics

• Literals
  Literals can be considered constants that do not change in value.

• Input parameters
  Input parameters are designated by the question mark followed by a number; for example: ?2. Input parameters are numbered starting at 1 and correspond to the arguments of the finder or select method; therefore, a query must not contain an input parameter that exceeds the number of input arguments.

• WebSphere Application Server Expressions
  An expression specifies a value.

• Basic predicates
  A basic predicate compares two values.

• Quantified predicates
  A quantified predicate compares a value with a set of values produced by a subselect.

• BETWEEN predicate
  The BETWEEN predicate determines whether a given value lies between two other given values.

• IN predicate
  The IN predicate compares a value to a set of values.

• LIKE predicate
  The LIKE predicate searches a string value for a certain pattern.

• NULL predicate
  The NULL predicate tests for null values.

• EMPTY collection predicate
  We can use the EMPTY collection predicate to test if a multivalued relationship has no members.

• MEMBER OF predicate
  This expression tests whether the object reference specified by the single valued path expression or input parameter is a member of the designated collection.

• EXISTS predicate
  The exists predicate tests for the presence or absence of a condition specified by a subselect.

• IS OF TYPE predicate
  The IS OF TYPE predicate is used to test the type of an EJB reference. It is similar in function to the Java instance of operator.

Related concepts

EJB query language

Related tasks

Use EJB query