SQL: select a new column that true if row (in another table) exist












-1















I have tables that have columns look like this:



 Customer: cid, blah

Product: pid, blah

Order: cid, pid


I want the result table that have these columns:



cid, pid, (this column is 'true' when have (cid,pid) of that row in Order otherwise 'false')



for example:



customer



1 blah

2 blah

3 blah


product



1 blah

2 blah

3 blah

4 blah


order



1 2

1 3

2 1

2 4

3 3


I want to find the sql query that have this result:



1 1 false

1 2 true

1 3 true

1 4 false

2 1 true

2 2 false

2 3 false

2 4 true

3 1 false

3 2 false

3 3 true

3 4 false


I'm trying to figure out that query but it is limited to my knowledge. Anyone know how to write that query?



// sorry, forget to mention that I want the blah from customer and product in the result as well



cid, blah, pid, blah, true/false









share|improve this question

























  • Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

    – philipxy
    Nov 24 '18 at 10:13
















-1















I have tables that have columns look like this:



 Customer: cid, blah

Product: pid, blah

Order: cid, pid


I want the result table that have these columns:



cid, pid, (this column is 'true' when have (cid,pid) of that row in Order otherwise 'false')



for example:



customer



1 blah

2 blah

3 blah


product



1 blah

2 blah

3 blah

4 blah


order



1 2

1 3

2 1

2 4

3 3


I want to find the sql query that have this result:



1 1 false

1 2 true

1 3 true

1 4 false

2 1 true

2 2 false

2 3 false

2 4 true

3 1 false

3 2 false

3 3 true

3 4 false


I'm trying to figure out that query but it is limited to my knowledge. Anyone know how to write that query?



// sorry, forget to mention that I want the blah from customer and product in the result as well



cid, blah, pid, blah, true/false









share|improve this question

























  • Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

    – philipxy
    Nov 24 '18 at 10:13














-1












-1








-1








I have tables that have columns look like this:



 Customer: cid, blah

Product: pid, blah

Order: cid, pid


I want the result table that have these columns:



cid, pid, (this column is 'true' when have (cid,pid) of that row in Order otherwise 'false')



for example:



customer



1 blah

2 blah

3 blah


product



1 blah

2 blah

3 blah

4 blah


order



1 2

1 3

2 1

2 4

3 3


I want to find the sql query that have this result:



1 1 false

1 2 true

1 3 true

1 4 false

2 1 true

2 2 false

2 3 false

2 4 true

3 1 false

3 2 false

3 3 true

3 4 false


I'm trying to figure out that query but it is limited to my knowledge. Anyone know how to write that query?



// sorry, forget to mention that I want the blah from customer and product in the result as well



cid, blah, pid, blah, true/false









share|improve this question
















I have tables that have columns look like this:



 Customer: cid, blah

Product: pid, blah

Order: cid, pid


I want the result table that have these columns:



cid, pid, (this column is 'true' when have (cid,pid) of that row in Order otherwise 'false')



for example:



customer



1 blah

2 blah

3 blah


product



1 blah

2 blah

3 blah

4 blah


order



1 2

1 3

2 1

2 4

3 3


I want to find the sql query that have this result:



1 1 false

1 2 true

1 3 true

1 4 false

2 1 true

2 2 false

2 3 false

2 4 true

3 1 false

3 2 false

3 3 true

3 4 false


I'm trying to figure out that query but it is limited to my knowledge. Anyone know how to write that query?



// sorry, forget to mention that I want the blah from customer and product in the result as well



cid, blah, pid, blah, true/false






mysql sql






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 24 '18 at 9:49







taepatipol

















asked Nov 24 '18 at 9:08









taepatipoltaepatipol

35




35













  • Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

    – philipxy
    Nov 24 '18 at 10:13



















  • Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

    – philipxy
    Nov 24 '18 at 10:13

















Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

– philipxy
Nov 24 '18 at 10:13





Please read & act on How to Ask, hits googling 'stackexchange homework' & the downvote arrow mouseover text.

– philipxy
Nov 24 '18 at 10:13












3 Answers
3






active

oldest

votes


















1














You may cross and left joins and case..when conditional statement as :



   select c.cid, p.pid,  
( case when o.cid*o.pid > 0 then 'true' else 'false' end )
as flag
from product p
cross join customer c
left join order_ o on o.cid = c.cid and o.pid = p.pid
order by c.cid, p.pid;


P.S. order is a keyword, so I replaced that with order_



Rextester Demo






share|improve this answer


























  • +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

    – Madhur Bhaiya
    Nov 24 '18 at 16:27











  • @MadhurBhaiya exactly, good catch thanks.

    – Barbaros Özhan
    Nov 24 '18 at 16:31



















0














 SELECT C.CID,P.PID,
CASE WHEN C.CID,P.PID IN
(SELECT CID,PID from
ORDER)
THEN "TRUE" END CASE
CASE WHEN C.CID,P.PID NOT IN
(SELECT CID,PID from
ORDER)
THEN "FALSE" END CASE
FROM CUSTOMER C,PRODUCT P ;



You need a case statement for that.







share|improve this answer































    0














    this is the simplest way :



    (
    SELECT O.cid, O.pid, 'true'
    FROM order O
    Where (O.cid, O.pid) in
    (SELECT C.cid, p.pid,
    FROM customer C CROSS JOIN product P)
    )
    UNION
    (
    SELECT O.cid, O.pid, 'false'
    FROM order O
    Where (O.cid, O.pid) not in
    (SELECT C.cid, p.pid,
    FROM customer C CROSS JOIN product P)
    )





    share|improve this answer


























    • I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

      – taepatipol
      Nov 24 '18 at 10:54













    • did you execute it?

      – FatemehNB
      Nov 24 '18 at 13:28











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    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1














    You may cross and left joins and case..when conditional statement as :



       select c.cid, p.pid,  
    ( case when o.cid*o.pid > 0 then 'true' else 'false' end )
    as flag
    from product p
    cross join customer c
    left join order_ o on o.cid = c.cid and o.pid = p.pid
    order by c.cid, p.pid;


    P.S. order is a keyword, so I replaced that with order_



    Rextester Demo






    share|improve this answer


























    • +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

      – Madhur Bhaiya
      Nov 24 '18 at 16:27











    • @MadhurBhaiya exactly, good catch thanks.

      – Barbaros Özhan
      Nov 24 '18 at 16:31
















    1














    You may cross and left joins and case..when conditional statement as :



       select c.cid, p.pid,  
    ( case when o.cid*o.pid > 0 then 'true' else 'false' end )
    as flag
    from product p
    cross join customer c
    left join order_ o on o.cid = c.cid and o.pid = p.pid
    order by c.cid, p.pid;


    P.S. order is a keyword, so I replaced that with order_



    Rextester Demo






    share|improve this answer


























    • +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

      – Madhur Bhaiya
      Nov 24 '18 at 16:27











    • @MadhurBhaiya exactly, good catch thanks.

      – Barbaros Özhan
      Nov 24 '18 at 16:31














    1












    1








    1







    You may cross and left joins and case..when conditional statement as :



       select c.cid, p.pid,  
    ( case when o.cid*o.pid > 0 then 'true' else 'false' end )
    as flag
    from product p
    cross join customer c
    left join order_ o on o.cid = c.cid and o.pid = p.pid
    order by c.cid, p.pid;


    P.S. order is a keyword, so I replaced that with order_



    Rextester Demo






    share|improve this answer















    You may cross and left joins and case..when conditional statement as :



       select c.cid, p.pid,  
    ( case when o.cid*o.pid > 0 then 'true' else 'false' end )
    as flag
    from product p
    cross join customer c
    left join order_ o on o.cid = c.cid and o.pid = p.pid
    order by c.cid, p.pid;


    P.S. order is a keyword, so I replaced that with order_



    Rextester Demo







    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited Nov 24 '18 at 16:31

























    answered Nov 24 '18 at 9:23









    Barbaros ÖzhanBarbaros Özhan

    13.4k71633




    13.4k71633













    • +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

      – Madhur Bhaiya
      Nov 24 '18 at 16:27











    • @MadhurBhaiya exactly, good catch thanks.

      – Barbaros Özhan
      Nov 24 '18 at 16:31



















    • +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

      – Madhur Bhaiya
      Nov 24 '18 at 16:27











    • @MadhurBhaiya exactly, good catch thanks.

      – Barbaros Özhan
      Nov 24 '18 at 16:31

















    +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

    – Madhur Bhaiya
    Nov 24 '18 at 16:27





    +1 as this is the best approach. However, I don't think that coalesce(o.cid,0)*coalesce(o.pid,0) is needed. Checking on any one field is enough, as your left join is based on two conditions (two columns).

    – Madhur Bhaiya
    Nov 24 '18 at 16:27













    @MadhurBhaiya exactly, good catch thanks.

    – Barbaros Özhan
    Nov 24 '18 at 16:31





    @MadhurBhaiya exactly, good catch thanks.

    – Barbaros Özhan
    Nov 24 '18 at 16:31













    0














     SELECT C.CID,P.PID,
    CASE WHEN C.CID,P.PID IN
    (SELECT CID,PID from
    ORDER)
    THEN "TRUE" END CASE
    CASE WHEN C.CID,P.PID NOT IN
    (SELECT CID,PID from
    ORDER)
    THEN "FALSE" END CASE
    FROM CUSTOMER C,PRODUCT P ;



    You need a case statement for that.







    share|improve this answer




























      0














       SELECT C.CID,P.PID,
      CASE WHEN C.CID,P.PID IN
      (SELECT CID,PID from
      ORDER)
      THEN "TRUE" END CASE
      CASE WHEN C.CID,P.PID NOT IN
      (SELECT CID,PID from
      ORDER)
      THEN "FALSE" END CASE
      FROM CUSTOMER C,PRODUCT P ;



      You need a case statement for that.







      share|improve this answer


























        0












        0








        0







         SELECT C.CID,P.PID,
        CASE WHEN C.CID,P.PID IN
        (SELECT CID,PID from
        ORDER)
        THEN "TRUE" END CASE
        CASE WHEN C.CID,P.PID NOT IN
        (SELECT CID,PID from
        ORDER)
        THEN "FALSE" END CASE
        FROM CUSTOMER C,PRODUCT P ;



        You need a case statement for that.







        share|improve this answer













         SELECT C.CID,P.PID,
        CASE WHEN C.CID,P.PID IN
        (SELECT CID,PID from
        ORDER)
        THEN "TRUE" END CASE
        CASE WHEN C.CID,P.PID NOT IN
        (SELECT CID,PID from
        ORDER)
        THEN "FALSE" END CASE
        FROM CUSTOMER C,PRODUCT P ;



        You need a case statement for that.








        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 24 '18 at 9:23









        Himanshu AhujaHimanshu Ahuja

        6792217




        6792217























            0














            this is the simplest way :



            (
            SELECT O.cid, O.pid, 'true'
            FROM order O
            Where (O.cid, O.pid) in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )
            UNION
            (
            SELECT O.cid, O.pid, 'false'
            FROM order O
            Where (O.cid, O.pid) not in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )





            share|improve this answer


























            • I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

              – taepatipol
              Nov 24 '18 at 10:54













            • did you execute it?

              – FatemehNB
              Nov 24 '18 at 13:28
















            0














            this is the simplest way :



            (
            SELECT O.cid, O.pid, 'true'
            FROM order O
            Where (O.cid, O.pid) in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )
            UNION
            (
            SELECT O.cid, O.pid, 'false'
            FROM order O
            Where (O.cid, O.pid) not in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )





            share|improve this answer


























            • I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

              – taepatipol
              Nov 24 '18 at 10:54













            • did you execute it?

              – FatemehNB
              Nov 24 '18 at 13:28














            0












            0








            0







            this is the simplest way :



            (
            SELECT O.cid, O.pid, 'true'
            FROM order O
            Where (O.cid, O.pid) in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )
            UNION
            (
            SELECT O.cid, O.pid, 'false'
            FROM order O
            Where (O.cid, O.pid) not in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )





            share|improve this answer















            this is the simplest way :



            (
            SELECT O.cid, O.pid, 'true'
            FROM order O
            Where (O.cid, O.pid) in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )
            UNION
            (
            SELECT O.cid, O.pid, 'false'
            FROM order O
            Where (O.cid, O.pid) not in
            (SELECT C.cid, p.pid,
            FROM customer C CROSS JOIN product P)
            )






            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited Nov 24 '18 at 9:29

























            answered Nov 24 '18 at 9:24









            FatemehNBFatemehNB

            25126




            25126













            • I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

              – taepatipol
              Nov 24 '18 at 10:54













            • did you execute it?

              – FatemehNB
              Nov 24 '18 at 13:28



















            • I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

              – taepatipol
              Nov 24 '18 at 10:54













            • did you execute it?

              – FatemehNB
              Nov 24 '18 at 13:28

















            I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

            – taepatipol
            Nov 24 '18 at 10:54







            I think the code under the UNION is not work. There aren't any row in O that not in C cross join P. I think it should be customer C CROSS JOIN product P instead of order O.

            – taepatipol
            Nov 24 '18 at 10:54















            did you execute it?

            – FatemehNB
            Nov 24 '18 at 13:28





            did you execute it?

            – FatemehNB
            Nov 24 '18 at 13:28


















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