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The syntax of the Java Persistence Query Language (JPQL) is very similar to the syntax ... between SQL and JPQL is that SQL works with relational database tables, records and fields, whereas JPQL works with Java classes and objects. For example, a JPQL query can retrieve and return entity

Query expressions are the foundations on which JPQL and criteria queries are built. Every query consists of jpql/structure">clauses - SELECT, FROM, WHERE, GROUP BY, HAVING and ORDER BY, and each clause consists of JPQL / Criteria query expressions

Literals in JPQL, as in Java, represent constant values. JPQL supports various types ... >). JPQL literals should be used sparingly as queries that use JPQL queries when a single constant value is always used and never replaced.

The ability to retrieve managed entity objects is a major advantage of JPQL ... . JPA 2 adds the ability to use almost any valid jpql/expression">JPQL ... must always be specified explicitly - JPQL does not support the "SELECT *" expression

class and all its descendant entity classes). Identification variables are always polymorphic. JPQL ... , however, adds support for filtering instances of specific types at the jpql/where">WHERE clause level by using a jpql/path#entity_type_expressions

. It is essential in any JPQL query that retrieves selective objects from the database. Out of the four optional clauses of JPQL queries, the WHERE clause is definitely the most frequently used. JPQL

and embeddable classes) are represented in JPQL by the following types of expressions: jpql/from">Variables - FROM identification variables ... . But more often they are used in JPQL path expressions that navigate to values of simple types (number, boolean

The JPA Query Language (JPQL) can be considered as an object oriented version of SQL. Users familiar with SQL should find JPQL very easy to learn and use. This chapter explains how to use JPQL as well as how to use the JPA Criteria API, which provides an alternative way for building

Numeric values may appear in JPQL queries in many forms: as jpql/literal#numeric_literals">numeric literals - e.g. 123- when numeric values are assigned as arguments. as jpql/path

Most JPQL queries use at least one comparison operator in their WHERE clause.   Set 1 - JPQL / SQL JPQL follows the SQL notation, where Java uses