WAS v8.5 > Develop applications > Develop Dynamic and EJB query > Develop applications that use EJB query > EJB query language

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.
• WAS, 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.
• 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.
• WAS, 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

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