JPA 查询like Escape示例JPA 查询like Escape示例.pdf

JPA 查询like Escape⽰例 JPA教程 - JPA查询like Escape⽰例 如果模式字符串包含应匹配的下划线或百分号，则ESCAPE⼦句可以使⽤\指定转 字 符： SELECT d FROM Department d WHERE LIKE QA\_% ESCAPE \ 例⼦ 下⾯的代码来⾃PersonDaoImpl .j ava 。 pa kage n.w3 s hool. ommon; import java.util.List; import javax .persisten e.EntityManager; import javax .persisten e.Persisten eContext; import org.springframework.transa tion.annotation.Transa tional; @Transa tional publi lass PersonDaoImpl { publi void test() { prepareData(); List l = em. reateQuery( SELECT d FROM Department d WHERE LIKE Q\\_% ESCA .getResultList(); for (Obje t p : l) { printResult(p); } } private void prepareData() { Address address = new Address(); address.setState(BC); Professor p = new Professor(); p.setId(0); p.setName(TOM); p.setSalary(1111L); p.setAddress(address); Department d = new Department(); d.setId(1); d.setName(Design); p.setDepartment(d); d.getProfessors().add(p); Phone phone = new Phone(); phone.setId(1); phone.setNumber(111-111-1111); phone.setProfessor(p); em.persist(p); em.persist(phone); em.persist(address); em.persist(d); } private stati void printResult(Obje t result) { if (result == null) { System.out.print(NULL); } else if (result instan eof Obje t[]) { Obje t[] row = (Obje t[]) result; System.out.print([); for (int i = 0; i row .length; i++) { printResult(row[i]); } System.out.print(]); } else if (result instan eof Long || result instan eof Double || result instan eof String) { System.out.print(result.getClass().getName() + : + result } else { System.out.print(result); } System.out.println(); } @Persisten eContext private EntityManager em; } 以下代码来⾃Professor .j ava 。 pa kage n.w3 s hool. ommon; impor