如何在mysql中获取上一季度的细节

Question

我有两张桌子

CREATE TABLE j_work_status (
    Work_req_id int(8) NOT NULL,
    Work_status varchar(50) NOT NULL,
    Date_Requested timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    date_assigned timestamp NULL DEFAULT NULL,
    Date_completed timestamp NULL DEFAULT NULL,
    Resource varchar(100) DEFAULT NULL,
    Completed_by varchar(50) DEFAULT NULL,
    PRIMARY KEY (Work_req_id),
    CONSTRAINT j_work_status_ibfk_1 FOREIGN KEY (Work_req_id)
        REFERENCES j_work_requests (Work_Req_ID)
)  ENGINE=InnoDB DEFAULT CHARSET=utf8

和

CREATE TABLE j_survey_response (
    Work_req_id int(8) NOT NULL,
    Satisfaction_score tinyint(2) DEFAULT '0',
    Response_score tinyint(2) DEFAULT '0',
    Responder_score tinyint(2) DEFAULT '0',
    Service_score tinyint(2) DEFAULT '0',
    Score_avg decimal(3 , 2 ) DEFAULT '0.00',
    Satisfaction_notes varchar(500) DEFAULT NULL,
    PRIMARY KEY (Work_req_id),
    CONSTRAINT j_survey_response_ibfk_1 FOREIGN KEY (Work_req_id)
        REFERENCES j_work_requests (Work_Req_ID)
)  ENGINE=InnoDB DEFAULT CHARSET=utf8

这两个表都有近20K的记录。 如果给出年份和季度，我需要显示其work_status完成的前3个季度的得分_avg的计数。

例如，如果年份= 2016年和季度= 1，我需要显示Q1-2016，Q4-2015，Q3-2015，Q2-2015的详细信息。

直到现在我有查询显示按年份和季度分组的所有详细信息。

select 
    work_status,
    count(score_avg) survey_completed,
    quarter(date_completed) Quarter,
    year(date_completed) Year
from
    j_work_status
        join
    j_survey_response ON j_survey_response.work_req_id = j_work_status.work_req_id
where
    work_status = 'complete' and year(date_completed)
group by Quarter , Year

请有人帮助我找到之前的3季度细节