Агрегатные функции

ДА

SELECT AVG(o.quantity) FROM app_Order o

НЕТ: агрегатные функции со скалярными выражениями (особенность EclipseLink)

SELECT AVG(o.quantity)/2.0 FROM app_Order o

SELECT AVG(o.quantity * o.price) FROM app_Order o

ALL, ANY, SOME

ДА

SELECT emp FROM app_Employee emp WHERE emp.salary > ALL (SELECT m.salary FROM app_Manager m WHERE m.department = emp.department)

Арифметические функции (INDEX, SIZE, ABS, SQRT, MOD)

ДА

SELECT w.name FROM app_Course c JOIN c.studentWaitlist w WHERE c.name = 'Calculus' AND INDEX(w) = 0

SELECT w.name FROM app_Course c WHERE c.name = 'Calculus' AND SIZE(c.studentWaitlist) = 1

SELECT w.name FROM app_Course c WHERE c.name = 'Calculus' AND ABS(c.time) = 10

SELECT w.name FROM app_Course c WHERE c.name = 'Calculus' AND SQRT(c.time) = 10.5

SELECT w.name FROM app_Course c WHERE c.name = 'Calculus' AND MOD(c.time, c.time1) = 2

CASE

ДА

SELECT e.name, f.name, CONCAT(CASE WHEN f.annualMiles > 50000 THEN 'Platinum ' WHEN f.annualMiles > 25000 THEN 'Gold ' ELSE '' END, 'Frequent Flyer') FROM app_Employee e JOIN e.frequentFlierPlan f

НЕТ: CASE в UPDATE-запросе

UPDATE app_Employee e SET e.salary = CASE e.rating WHEN 1 THEN e.salary * 1.1 WHEN 2 THEN e.salary * 1.05 ELSE e.salary * 1.01 END

Функции даты и времени (CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP)

ДА

SELECT e FROM app_Order e WHERE e.date = CURRENT_DATE

Функции EclipseLink (CAST, REGEXP, EXTRACT)

ДА

SELECT EXTRACT(YEAR FROM e.createTs) FROM app_MyEntity e WHERE EXTRACT(YEAR FROM e.createTs) > 2012

SELECT e FROM app_MyEntity e WHERE e.name REGEXP '.*'

SELECT CAST(e.number text) FROM app_MyEntity e WHERE e.path LIKE CAST(:ds$myEntityDs.id text)

НЕТ: CAST в запросе GROUP BY

SELECT e FROM app_Order e WHERE e.amount > 100 GROUP BY CAST(e.orderDate date)

Операторы типов сущности

ДА: тип сущности передаётся как параметр

SELECT e FROM app_Employee e WHERE TYPE(e) IN (:empType1, :empType2)

НЕТ: прямая ссылка на сущность

SELECT e FROM app_Employee e WHERE TYPE(e) IN (app_Exempt, app_Contractor)

Вызов функций

ДА: результат с операторами сравнения

SELECT u FROM sec$User u WHERE function('DAYOFMONTH', u.createTs) = 1

НЕТ: прямое использование результата функции

SELECT u FROM sec$User u WHERE function('hasRoles', u.createdBy, u.login)

IN

ДА

SELECT e FROM Employee e, IN(e.projects) p WHERE p.budget > 1000000

IS EMPTY для коллекций

ДА

SELECT e FROM Employee e WHERE e.projects IS EMPTY

KEY/VALUE

НЕТ

SELECT v.location.street, KEY(i).title, VALUE(i) FROM app_VideoStore v JOIN v.videoInventory i WHERE v.location.zipcode = '94301' AND VALUE(i) > 0

Литералы

ДА

SELECT e FROM app_Employee e WHERE e.name = 'Bob'

SELECT e FROM app_Employee e WHERE e.id = 1234

SELECT e FROM app_Employee e WHERE e.id = 1234L

SELECT s FROM app_Stat s WHERE s.ratio > 3.14F

SELECT s FROM app_Stat s WHERE s.ratio > 3.14e32D

SELECT e FROM app_Employee e WHERE e.active = TRUE

НЕТ: литералы даты и времени

SELECT e FROM app_Employee e WHERE e.startDate = {d'2012-01-03'}

SELECT e FROM app_Employee e WHERE e.startTime = {t'09:00:00'}

SELECT e FROM app_Employee e WHERE e.version = {ts'2012-01-03 09:00:00.000000001'}

MEMBER OF

ДА: для полей и запросов

SELECT d FROM app_Department d WHERE (select e from app_Employee e where e.id = :eParam) MEMBER OF e.employees

НЕТ: для литералов

SELECT e FROM app_Employee e WHERE 'write code' MEMBER OF e.codes

NEW в SELECT

ДА

SELECT NEW com.acme.example.CustomerDetails(c.id, c.status, o.count) FROM app_Customer c JOIN c.orders o WHERE o.count > 100

NULLIF/COALESCE

ДА

SELECT NULLIF(emp.salary, 10) FROM app_Employee emp

SELECT COALESCE(emp.salary, emp.salaryOld, 10) FROM app_Employee emp

NULLS FIRST, NULLS LAST в order by

ДА

SELECT h FROM sec$GroupHierarchy h ORDER BY h.level DESC NULLS FIRST

Строковые функции (CONCAT, SUBSTRING, TRIM, LOWER, UPPER, LENGTH, LOCATE)

ДА

SELECT x FROM app_Magazine x WHERE CONCAT(x.title, 's') = 'JDJs'

SELECT x FROM app_Magazine x WHERE SUBSTRING(x.title, 1, 1) = 'J'

SELECT x FROM app_Magazine x WHERE LOWER(x.title) = 'd'

SELECT x FROM app_Magazine x WHERE UPPER(x.title) = 'D'

SELECT x FROM app_Magazine x WHERE LENGTH(x.title) = 10

SELECT x FROM app_Magazine x WHERE LOCATE('A', x.title, 4) = 6

SELECT x FROM app_Magazine x WHERE TRIM(TRAILING FROM x.title) = 'D'

НЕТ: TRIM не поддерживается с trim char

SELECT x FROM app_Magazine x WHERE TRIM(TRAILING 'J' FROM x.title) = 'D'

Вложенные запросы

ДА

SELECT goodCustomer FROM app_Customer goodCustomer WHERE goodCustomer.balanceOwed < (SELECT AVG(c.balanceOwed) FROM app_Customer c)

НЕТ: path-выражения вместо имени сущности в FROM подзапроса

SELECT c FROM app_Customer c WHERE (SELECT AVG(o.price) FROM c.orders o) > 100

TREAT

ДА

SELECT e FROM app_Employee e JOIN TREAT(e.projects AS app_LargeProject) p WHERE p.budget > 1000000

НЕТ: TREAT в WHERE-выражениях

SELECT e FROM Employee e JOIN e.projects p WHERE TREAT(p as LargeProject).budget > 1000000