class Member {
private String memberNo;
private String name;
@Relation(relationType = RelationType.HAS_MANY)
private List orders;
}
class Order {
private String no;
private Long memberId;
@Relation(relationType = RelationType.BELONGS_TO)
private Member member;
}
2）数据库表定义如下：
create table members (
member_no varchar not null,
name varchar
);
create table members (
member_no varchar not null,
member_id int(10) not null,
name varchar
);
Member.create(newMember);
Member.create(newMember, true); // Create a member without validating
Member.create(Member.newInstanceFrom(memberHash));
Member.create(new Member[]{newMember1, newMember2, newMember3}, false);
Member.update(1L, newMember, true); // Update a member by primary key and skip validationg
Member.update("name = ?", "name = ?", newName, oldName);
Member.destroy(1L); // Delete a member by primary key
Member.destroy("name = ?", "Mary");
4.5 事务
4.5.1 基于Annotation 的事务
// The method will be executed in a database thransaction
@Transactional
public static void makeOrder(Order order, OrderLine... orderLines) throws SQLException {
Order.create(order, false);
OrderLine.create(orderLines, false);
}
// Create a Page instance with current page and page size
Page page = Page.create(0, 10);
PagedList members = Member.pagedQueryAll(page, Member.HAS_MANY_ORDERS);
PagedList members = Member.pagedQuery(page, "name = ?", "braisdom");
Member newMember = new Member()
.setNo("100")
.setName("Pamela")
.setGender(1)
.setMobile("15011112222");
// Violations occurred in field 'no'
Validator.Violation[] violations = newMember.validate();
4.9.2 创建对象时 `validate`
Member newMember = new Member()
.setNo("100000")
.setName("Pamela")
.setGender(1)
.setMobile("15011112222");
Member.create(newMember);
Member.create(newMember, true); // Skip validation
4.10 自定义SQL
Member.execute("DELETE FROM members WHERE name = ?", "Pamela");
Member.Table member = Member.asTable();
Order.Table order = Order.asTable();
Select select = new Select();
select.project(member.no, member.name, count().as("order_count"))
.from(member, order)
.where(member.id.eq(order.memberId))
.groupBy(member.no, member.name);
List members = select.execute(Member.class);
SELECT `T0`.`NO` , `T0`.`name` , COUNT(*) AS `order_count`
FROM `members` AS `T0`, `orders` AS `T1`
WHERE (`T0`.`id` = `T1`.`member_id` )
GROUP BY `T0`.`NO` , `T0`.`name`
5.1.2 显式Join
Member.Table member = Member.asTable();
Order.Table order = Order.asTable();
Select select = new Select();
select.project(member.no, member.name, count().as("order_count"))
.from(member)
.leftOuterJoin(order, order.memberId.eq(member.id))
.groupBy(member.no, member.name);
List members = select.execute(Member.class);
SELECT `T0`.`NO` , `T0`.`name` , COUNT(*) AS `order_count`
FROM `members` AS `T0`
LEFT OUTER JOIN `orders` AS `T1` ON (`T1`.`member_id` = `T0`.`id` )
GROUP BY `T0`.`NO` , `T0`.`name`
5.2 分页查询
Member.Table member = Member.asTable();
Order.Table order = Order.asTable();
Paginator paginator = Databases.getPaginator();
Page page = Page.create(0, 20);
Select select = new Select();
select.project(member.no, member.name, count().as("order_count"))
.from(member, order)
.where(member.id.eq(order.memberId))
.groupBy(member.no, member.name);
PagedList members = paginator.paginate(page, select, Member.class);
-- Counting SQL
SELECT COUNT(*) AS count_
FROM (
SELECT
`T0`.`NO`,
`T0`.`name`,
COUNT(*) AS `order_count`
FROM `members` AS `T0`, `orders` AS `T1`
WHERE (`T0`.`id` = `T1`.`member_id`)
GROUP BY `T0`.`NO`, `T0`.`name`
) T
-- Querying SQL
SELECT `T0`.`NO`, `T0`.`name`, COUNT(*) AS `order_count`
FROM `members` AS `T0`, `orders` AS `T1`
WHERE (`T0`.`id` = `T1`.`member_id`)
GROUP BY `T0`.`NO`, `T0`.`name`
LIMIT 0, 20
5.3 复杂表达式查询
ObjectiveSQL 通过运算符重域技术使得Expression 也可以参与各类运算符计算，从而使得Java 代码变得简单易懂，而不是通过各类运算符方法进行计算。ObjectiveSQL 表达式计算时并不能够与SQL 表达完匹配，默认情况下所有表达式均可以进行算术运算，在IntelliJ IDEA 中并不能给出完整的提醒，例如：JoinExpression 也可以进行算术运算，此时在IntelliJ IDEA 中并不会出现语法错误的提醒，但在执行运算过程中会抛出 UnsupportedArithmeticalException，该异常为RuntimeException 的子类。
SELECT ((((SUM(`T0`.`amount` ) / SUM(`T0`.`quantity` ) )) * 100)) AS unit_amount
FROM `orders` AS `T0`
WHERE ((`T0`.`quantity` > 30)
AND `T0`.`sales_at` BETWEEN '2020-05-01 00:00:00' AND '2020-05-02 23:59:59' )
GROUP BY `T0`.`member_id`
SELECT ((((SUM(`T0`.`amount` ) / SUM(`T0`.`quantity` ) )) * 100)) AS unit_amount
FROM `orders` AS `T0`
WHERE ((1 = 1) AND `T0`.`NO` IN ('202000001', '202000002', '202000003') )
GROUP BY `T0`.`member_id`
java中最常用jar包的用途
jar包用途axis.jarSOAP引擎包commons-discovery-0.2.jar用来发现、查找和实现可插入式接口，提供一些一般类实例化、单件的生命周期管理的常用方法.jaxrpc.jarAxis运行所需要的组件包saaj.jar创建到端点的点到点连接的方法、创建并处理SOAP消息和附件的方法，以及接收和处理SOAP错误的方法. w
创建图表事件监听非常简单：首先是通过addEventListener('监听类型',js监听方法)添加事件监听，然后在js监听方法中定义具体监听逻辑。
以钻取操作为例，当用户点击图表某一个point的时候弹出point的name和value，代码如下：
<script>
//创建AnyChart
var chart = new AnyChart();
//添加钻取操作&quo
我们来看下面的例子：
create or replace view testview
as
select empno,ename from emp where ename like ‘M%’
with check option;
这里我们创建了一个视图，并使用了with check option来限制了视图。 然后我们来看一下视图包含的结果：
select * from testv
