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Logical Operators in JPQL and Criteria API

Logical operators in JPQL and in JPA criteria queries enable composition of complex JPQL boolean expressions out of simple JPQL boolean expressions. Logical Operators ObjectDB supports 2 sets of logical operators, as shown in the following table: Set 1 - JPQL / SQL Set 2 - Java / JDO AND && OR

Comparison in JPQL and Criteria API

to <>. When at least one of the two operands is NULL, == and != implement the ordinary Java logic, in which, for example, null == null is true. All the other operators implement the SQL logic in which NULL represents an unknown value ... follow the logic of Java's equals, comparing the content rather than the identity. Date values

Logical "or" works not correcly when field is @Id and first position

The following code doesn't respect the logical "or" correctly. Instead of returns all 2 datasets it returns only this one, which matches the first predicate in the or. BUT: this happens only, if the field for the "or" is the first one defined as @Id. public class OrTest {     @Entity     static

JPA Query Expressions (JPQL / Criteria)

] MEMBER [OF] and the [NOT] LIKE operator. Logical operators: AND, OR, NOT. In addition, JPA queries ... , isMember, isNotMember, size). Comparison expressions (equal, notEqual, gt, ge, lt, le, between, isNull, ...) Logical expressions (and, or, not, isTrue).

WHERE clause (JPQL / Criteria API)

, which includes many operators (arithmetic operators, relational operators, logical operators ... ),          cb.lt(c.get("area"), a)     ) ); See the Logical Operators page for explanations on boolean

ObjectDB Object Database Features

. Comparison operators (<, <=, >=, <>, =, !=, ==, BETWEEN, IS NULL). Logical operators (AND, OR, NOT

JPA Criteria API Queries

expressions (equal, notEqual, gt, ge, lt, le, between, isNull, ...) Logical expressions (and, or, not

JPA Persistence Unit

A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes, embeddable classes and mapped superclasses) with related settings. Defining a persistence unit is optional when using ObjectDB, but required by JPA. persistence.xml Persistence units are defined in

[ODB1] Chapter 7 - JDOQL Queries

, double). Logical Operators Logical operators (&&, ||, !) generate complex boolean expressions


the enhancer so that fields referenced can be used in the business logic of the method. Since: JDO 2.0 void

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

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