mysql常用函数之group_concat()、group by、count()、case when then的使用

select
    group_concat(ttop.user_name) as testStr
from t_table_one_parent ttop;

select
    group_concat(ttop.user_name separator ';') as testStr
from t_table_one_parent ttop;

select
    group_concat(distinct ttop.user_name separator ';') as testStr
from t_table_one_parent ttop;

select
    group_concat(distinct ttop.user_name, ttop.company_code separator ';') as testStr
from t_table_one_parent ttop;

select
    group_concat(distinct ttop.user_name, ',', ttop.company_code separator ';') as testStr
from t_table_one_parent ttop;

select
     user_name as userName,
     count(user_name) as ctUserName
from t_table_one_parent ttop group by user_name;

select
     user_name as userName,
     count(user_name) as ctUserName,
     sum(total_account_balance) as sumTab
from t_table_one_parent ttop group by user_name;

create table if not exists t_department_info
(
    id            bigint      not null primary key auto_increment comment '主键id',
    dept_name     varchar(50) not null comment '部门名称',
    dept_director varchar(20) not null comment '部门主管',
    create_by     bigint comment '创建人Id',
    create_date   datetime    not null default now() comment '创建时间',
    update_by     bigint comment '更新人Id',
    update_date   datetime    not null default now() on update now() comment '更新时间'
) engine = InnoDB
  auto_increment = 1
  default charset = utf8 comment '部门信息表';
 
 
create table if not exists t_person_info
(
    id             bigint      not null primary key auto_increment comment '主键id',
    person_name    varchar(10) not null comment '人员名称',
    id_number      varchar(50) not null comment '省份证号',
    gender         varchar(5)  not null comment '性别，M男、F女',
    induction_date datetime    null comment '入职日期',
    quit_date      datetime    null comment '离职日期',
    if_on_job      tinyint(1)           default 1 comment '是否在职状态，0-否，1-是',
    dept_id        bigint      null comment '部门Id',
    create_by      bigint comment '创建人Id',
    create_date    datetime    not null default now() comment '创建时间',
    update_by      bigint comment '更新人Id',
    update_date    datetime    not null default now() on update now() comment '更新时间'
) engine = InnoDB
  auto_increment = 1
  default charset = utf8 comment '人员资料信息表';
 
 
 
 
 
 
-- 写入数据
INSERT INTO any_case.t_department_info (id, dept_name, dept_director, create_by, create_date, update_by, update_date) VALUES (1, '研发部', '张三', 1, '2022-12-22 16:38:10', null, '2022-12-22 16:38:10');
INSERT INTO any_case.t_department_info (id, dept_name, dept_director, create_by, create_date, update_by, update_date) VALUES (2, '测试部', '张三', 1, '2022-12-22 16:38:10', null, '2022-12-22 16:38:10');
INSERT INTO any_case.t_department_info (id, dept_name, dept_director, create_by, create_date, update_by, update_date) VALUES (3, '运维部', '李四', 1, '2022-12-22 16:38:10', null, '2022-12-22 16:38:10');
 
 
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (1, '张三', '123456789987654321', 'M', '2022-11-23 00:40:35', null, 1, 1, 1, '2022-12-22 16:40:48', null, '2022-12-22 16:40:48');
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (2, '李四', '123456789987654321', 'F', '2022-11-23 00:40:35', '2022-12-23 00:54:47', 0, 1, 1, '2022-12-22 16:40:48', null, '2022-12-22 16:54:40');
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (3, '王五', '123456789987654321', 'M', '2022-11-23 00:40:35', '2022-11-30 00:54:54', 0, 1, 1, '2022-12-22 16:40:48', null, '2022-12-23 02:13:29');
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (4, '赵六', '123456789987654321', 'F', '2022-11-23 00:40:35', null, 1, 2, 1, '2022-12-22 16:40:48', null, '2022-12-22 16:40:48');
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (5, '李七', '123456789987654321', 'M', '2022-11-23 00:40:35', null, 1, 2, 1, '2022-12-22 16:40:48', null, '2022-12-22 16:40:48');
INSERT INTO any_case.t_person_info (id, person_name, id_number, gender, induction_date, quit_date, if_on_job, dept_id, create_by, create_date, update_by, update_date) VALUES (6, '郑八', '123456789987654321', 'F', '2022-11-23 00:40:35', null, 1, 1, 1, '2022-12-22 16:41:17', null, '2022-12-22 17:00:22');

select tdi.dept_name,
       tdi.dept_director
       ,count(tpi.id) as allPersonNum	-- 全部人数
       ,count(case when tpi.if_on_job = 1 then tpi.id end) as ifOnJobNum -- 在职全部人数
       ,count(case when tpi.if_on_job = 1 and tpi.gender = 'M' then tpi.id end) as ifOnJobMNum -- 在职男性人数
       ,count(case when tpi.if_on_job = 1 and tpi.gender = 'F' then tpi.id end) as ifOnJobFNum -- 在职女性人数
       ,count(case when tpi.if_on_job = 0 then tpi.id end) as quitNum -- 离职总人数
       ,count(case when tpi.if_on_job = 0 and date_format(tpi.quit_date, '%Y-%m') = date_format(now(), '%Y-%m') then tpi.id end) as quitNumThisMonth -- 本月离职人数
from t_department_info tdi
left join t_person_info tpi on tpi.dept_id = tdi.id
#支持主表和从表过滤
where tdi.dept_director like '%张%'
  and (tpi.if_on_job = 0 and date_format(tpi.quit_date, '%Y-%m') = date_format(now(), '%Y-%m')) > 0
  and tpi.person_name like '%李%'
group by tdi.dept_name, tdi.dept_director;