SQL Server : concatenate distinct results into single column from matched table

Question

I have 3 tables EMP, SCHOOL, JOB ; structure and values are like this:

CREATE TABLE SCHOOL
(
    SCHOOLID CHAR(2),
    STUDENTID  SMALLINT,
    GRADE      CHAR(4)    
);

CREATE TABLE JOB 
(
    JOBID SMALLINT UNIQUE NOT NULL,
    JOBNAME CHAR(15)
);

CREATE TABLE EMP
(
    EMPID SMALLINT, 
    JOBID SMALLINT, 
    SAL SMALLINT, 
    CITYID SMALLINT,
    YEAR SMALLINT,
    SCHOOLID CHAR(2),
    SEX  CHAR(1),
    EMPCAT CHAR(2)
);

INSERT INTO SCHOOL(SCHOOLID, STUDENTID, GRADE) 
VALUES ('S1', 10, 'PKG'),
       ('S1', 20, 'LKG'),
       ('S2', 10, 'PKG'),
       ('S2', 20, 'LKG'),
       ('S2', 30, '1ST'),
       ('S2', 30, '2ND');

INSERT INTO JOB(JOBID, JOBNAME) 
VALUES (1, 'PRINCIPAL'),
       (2, 'ASST PRINCIPAL'),
       (3, 'TEACHING'),
       (4, 'CLERICAL'),
       (7, 'HELPER');

INSERT INTO EMP (EMPID , JOBID, SAL, CITYID, YEAR, SCHOOLID, SEX, EMPCAT) 
VALUES (100, 1, 1000, 10, 2015, 'S1', 'M', 'A'),
       (200, 2, 2000, 10, 2015, 'S1', 'M', 'B'),
       (300, 1, 2500, 10, 2015, 'S1', 'F', 'A'),
       (400, 1, 1000, 10, 2015, 'S2', 'M', 'B'),
       (500, 1, 3000, 10, 2015, 'S2', 'F', 'A'),
       (600, 3, 1000, 10, 2015, 'S2', 'M', 'A'),
       (700, 3, 2000, 20, 2015, 'S2', 'F', 'A');

For the given input cityid , YEAR ( Emp table), take all distinct SCHOOLIDs and for each SCHOOLID take distinct grade from SCHOOL table (all grades needs to be concatenated and displayed in single column) ;

And for each jobid (EMP) that matches with jobid (JOB), for each jobname (from job table ) get the counts of each sex (male and female) for the EMPCAT 'A', 'B' in horizontal way; and totals as well.

Output should be like this:

CITYID  SCHOOLID  GRADES              Jobname                  Male           FEMALE              TOTAL
                                                             A    B           A    B          
10      S1        PKG-LKG            PRINCIPAL               1    0           1    0                 2
10      S1        PKG-LKG            ASST PRINCIPAL          0    1           0    0                 1
10      S2        PKG-LKG-1ST        PRINCIPAL               0    1           1    0                 2
10      S2        PKG-LKG-1ST        TEACHING                1    0           0    0                 1
TOTAL                                                        1    2           2    0                 6

20      S2        PKG-LKG-1ST        TEACHING                1    0           0    0                 1     
TOTAL                                                        1    0           0    0                 1

How to concatenate school grades in single column and EMPCAT results in horizontal way ..?

Answer 1

I encountered a similar situation in the past. I had to loop the records using WHILE and concatenate the values in a field. In your case, you would compare a record with the previous one and if they are from the same city and school, you would do the concatenation in the field. It depends of course on how many records you have in your tables because processing this way is not very fast.

Answer 2

OK, this is ugly but it works, and does what you want. Totalling would be better done in the presentation layer but I have put the primary results into a temporary table so that we can then select from it and union it with totals, then order using CITYID and OrderKey to get the presentation youwant.

Declare @Results as table
(orderkey int, cityid int, schoolid varchar(5), Grades varchar(100), Jobname varchar(100), Male_A int, Male_B int, Female_A int, Female_B int)

INSERT INTO @results
Select DISTINCT 1 as orderkey, CITYID, e.schoolid , g.grades, j.JOBNAME, 
empcount.scount as Male_A, empcountB.scountB as Male_B, empcountFA.scountFA as Female_A, empcountFB.scountFB as Female_B

from emp e 

left join job j on e.JOBID=j.JOBID

outer apply (select STUFF((Select ',' + GRADE from school s where s.SCHOOLID=e.SCHOOLID FOR XML PATH('')),1,1,'' ) as grades) g
outer apply (select  count(sex) as  scount from emp ee where ee.jobid=e.jobid and sex='M' and ee.empcat='A'
and (select STUFF((Select ',' + GRADE from school s where s.SCHOOLID=ee.SCHOOLID FOR XML PATH('')),1,1,'' ))=g.grades
) empcount
outer apply (select  count(sex) as  scountB from emp ee where ee.jobid=e.jobid and sex='M' and ee.empcat='B'
and (select STUFF((Select ',' + GRADE from school s where s.SCHOOLID=ee.SCHOOLID FOR XML PATH('')),1,1,'' ))=g.grades
) empcountB
outer apply (select  count(sex) as  scountFA from emp ee where ee.jobid=e.jobid and sex='F' and ee.empcat='A'
and (select STUFF((Select ',' + GRADE from school s where s.SCHOOLID=ee.SCHOOLID FOR XML PATH('')),1,1,'' ))=g.grades
) empcountFA
outer apply (select  count(sex) as  scountFB from emp ee where ee.jobid=e.jobid and sex='F' and ee.empcat='B'
and (select STUFF((Select ',' + GRADE from school s where s.SCHOOLID=ee.SCHOOLID FOR XML PATH('')),1,1,'' ))=g.grades
) empcountFB

Select * from @results

UNION ALL

Select DISTINCT 99,CITYID, '' ,'TOTAL', '', 
sum(Male_A) as Male_A, sum(Male_B) as Male_B, sum(Female_A) as Female_A, sum(Female_B) as Female_B
from @results
group by CITYID

ORDER BY CITYID, orderkey

Answer 3

Some table valued functions might help, start with a function to concatenate the grades

ALTER FUNCTION [dbo].[GetSchoolGrades] ()
RETURNS 
@school_grades table
(
    SCHOOLID  CHAR(2),
    GRADES    CHAR(24)    
)
AS
BEGIN
    with cte_grades (SCHOOLID, GRADES) as
    (
        select a1.SCHOOLID, 
               (
                select rtrim(x1.GRADE) + '-'
                from   SCHOOL x1
                where  x1.SCHOOLID = a1.SCHOOLID
                group  by x1.GRADE
                for    xml path ('')
            ) as GRADES
        from   SCHOOL a1
        group  by a1.SCHOOLID
    ) 
    insert into @school_grades(SCHOOLID, GRADES)
    select SCHOOLID, LEFT(GRADES, len(GRADES) -1) as GRADES
    from   cte_grades;
    RETURN 
END

Now a function for the counts, based on parms

ALTER FUNCTION [dbo].[GetEmpCatCounts]
(
    @JOBID     SMALLINT,  
    @SCHOOLID  CHAR(2),
    @SEX       CHAR(1),
    @EMPCAT    CHAR(2)
)
RETURNS int
AS
BEGIN
    return (
       select count(*) from EMP m1 
       where  m1.JOBID    = @JOBID
       and    m1.SCHOOLID = @SCHOOLID
       and    m1.SEX      = @SEX
       and    m1.EMPCAT   = @EMPCAT
    )

END

Tie it all together like this

select a1.CITYID,
       a1.SCHOOLID,
       g1.GRADES,
       j1.JOBNAME,
       (select dbo.GetEmpCatCounts(a1.JOBID, a1.SCHOOLID, 'M', 'A')) as EMPCNT_MALE_A,
       (select dbo.GetEmpCatCounts(a1.JOBID, a1.SCHOOLID, 'M', 'B')) as EMPCNT_MALE_B,
       (select dbo.GetEmpCatCounts(a1.JOBID, a1.SCHOOLID, 'F', 'A')) as EMPCNT_FEMALE_A,
       (select dbo.GetEmpCatCounts(a1.JOBID, a1.SCHOOLID, 'F', 'B')) as EMPCNT_FEMALE_B
from   EMP  a1
join   JOB  j1 
on     a1.JOBID = j1.JOBID
join   GetSchoolGrades() g1 
on     a1.SCHOOLID = g1.SCHOOLID
group  by a1.CITYID,
       a1.JOBID,
       a1.SCHOOLID,
       g1.GRADES,
       j1.JOBNAME
order  by a1.CITYID,
       a1.SCHOOLID,
       a1.JOBID,
       g1.GRADES