查询模型使用示例

查询模型（query model）的特性及原理可以参考：查询模型使用文档

本文档使用下面模型生成的query model作为示例，描述query model的使用方式

@Data
@ToString(callSuper = true)
@Model(
        name = "员工模型",
        mainField = "staffName",
        fieldGroups = {
                @FieldGroup(fieldName = {Staff.staffNumber_field, Staff.staffName_field}),
                @FieldGroup(fieldName = {Staff.staffNumber_field, Staff.staffName_field}, type = FieldGroupType.SEARCHABLE),
                @FieldGroup(fieldName = {Staff.staffNumber_field, Staff.staffName_field}, type = FieldGroupType.SEARCH_SHOW),
        }
)
public class Staff extends BaseModel<Long> {

    @Field(name = "员工名称")
    private String staffName;

    @TextMeta(rule = "STRING(STAFF)+TIMES(yyyy-MM-dd)+INCRE(1,6,0,0)")
    @Field(name = "员工编号")
    private String staffNumber;

    @Field(name = "手机号", type = FieldType.Phone, nullable = false)
    @NotNull(message = "手机号不能为空")
    private String mobile;

    @Field(name = "邮箱", type = FieldType.Email)
    private String email;

    @Field(name = "出生日期", type = FieldType.Date)
    private Date birthday;

    /**
     * 非持久化字段，年龄通过 birthday 实时计算
     */
    @Transient
    @Field(name = "年龄")
    private Integer age;

    @Field(name = "住址", type = FieldType.Text)
    private String liveAddress;

    /**
     * 薪资, 主要为了引入 Currency 类型字段
     */
    @Field(name = "薪资", type = FieldType.Currency)
    private Currency salary;

    @Field(name = "岗位类型")
    @NotNull(message = "岗位类型不能为空")
    @DictionaryMeta(value = PositionType.class)
    private String positionType;

    @Field(name = "所属公司", nullable = false, type = FieldType.Link)
    @NotNull(message = "公司不能为空")
    @LinkMeta
    private Company company;

    /**
     * 多对多，员工可能属于多个虚拟组织，如纵向划分职能部门后，还有横向的架构评审委员会等虚拟部门
     */
    @Field(name = "部门", type = FieldType.LookupMany)
    @NotNull(message = "部门不能为空")
    @LookupMeta(linkField = StaffDepartmentRelation.staff_field)
    @JunctionMeta(model = StaffDepartmentRelation.class, lookupField = StaffDepartmentRelation.department_field)
    private List<Department> departments;

    /**
     * 一对一，一人一台笔记本电脑，一个笔记本同时只能所属一个员工
     */
    @Field(name = "办公设备")
    @LookupMeta
    private Equipment equipment;
}

级联查询

示例中嵌套查询了Staff.Department.id、Staff.Department.name、Staff.Department.Company.id、Staff.Department.Company.name字段，展示了三层嵌套，如果实际使用中嵌套深度更深，按照规律继续嵌套下去即可

QStaff staff = new QStaff();
Select select = new Select();
select.addField(Staff.id_field);
select.addField(Staff.staffName_field);

Set<Select.Field> deptSelect = new HashSet<>();
deptSelect.add(new Select.Field(Department.id_field));
deptSelect.add(new Select.Field(Department.name_field));

Set<Select.Field> companySelect = new HashSet<>();
companySelect.add(new Select.Field(Company.id_field));
companySelect.add(new Select.Field(Company.name_field));

deptSelect.add(new Select.Field(Department.company_field, companySelect));
select.addField(Staff.departments_field, deptSelect);

staff.getQueryParams().setSelect(select);

staff.setId(new QLongId(Lists.newArrayList(1L, 2L, 3L)));

List<Staff> all = DS.findAll(staff);

上面示例的sql：

select id,staffName,departments.id,departments.name,departments.company.id,departments.company.name from erp_Staff where id in (?)

IS NULL & IS NOT NULL

通过设置query model字段的Operators属性实现，意味着使用手动指定的操作比较当前字段，而不是自动推断字段的比较操作，Operators还有其他枚举，表示不同的操作，例如 != 、 not in 等。

QStaff staff = new QStaff();

QString staffName = new QString("");//value 不能是 null
staffName.setOperator(Operators.NOT_NULL);
//        staffName.setOperator(Operators.NULL);
staff.setStaffName(staffName);

List<Staff> all = DS.findAll(staff);

示例的sql：

select * from erp_Staff where staffName is not null

range

范围查询，不是query model中所有字段都可以使用这种方式查询，是RangeType子类的字段才能使用，需要注意的是，QString不是RangeType的子类，因此不能使用这种方式，QLong是RangeType的子类，但是QLongId不是RangeType子类，因此id字段也不能通过这种方式查询

QStaff staff = new QStaff();

QDate birthday = new QDate(DateUtils.parseDate("2020-1-1", "yyyy-MM-dd"), new Date());
staff.setBirthday(birthday);

List<Staff> all = DS.findAll(staff);

示例的sql：

select * from erp_Staff where birthday >= ? and birthday <= ?