Rows having records of a perticular type

  • Class table has people with the role of students and teachers. There should be at least one teacher in a class or every one is a student.

    How do I write a query so that for a given class type there should be at least one teacher available or every one is a student. i. if not teacher is available or every person in the class is a student then the query should return a zero, else one

    Table structure is

    CLASS

    id

    class_type_id

    person_type

    Name

    e.g

    id class_type_id person_type Name

    1 First Teacher John

    2 First Student Bobby

    3 First Student Kathy

    4 First Student Tony

    6 First Teacher Kate

    7 First Teacher John

    8 First Student Betty

    9 First Student Snowy

    Thanks in advance as always

    AK

  • Sounds like a homework question....

    If yes: what specific question do you have? We usually don't do someone's homework, but we'll be happy to assist you if you got stuck (which would expect that you started working on it on your own...) or if you have a specific question about how some SQL code works.

    If it's not homework: please describe the business case and include sample data as per the first link in my signature including expected result set and what you've tried so far.



    Lutz
    A pessimist is an optimist with experience.

    How to get fast answers to your question[/url]
    How to post performance related questions[/url]
    Links for Tally Table [/url] , Cross Tabs [/url] and Dynamic Cross Tabs [/url], Delimited Split Function[/url]

  • That's a good one. No this is not a H/W Question.

    We have a case where we need to get all the records which has a specific criteria. I had generalized my question into the Teacher student example.

    I can get this to work by selecting all the values and filtering them in the front end. Trying to figure out if this can be avoided by using one SQL query

    A-

  • Ash-N (2/15/2010)


    That's a good one. No this is not a H/W Question.

    We have a case where we need to get all the records which has a specific criteria. I had generalized my question into the Teacher student example.

    I can get this to work by selecting all the values and filtering them in the front end. Trying to figure out if this can be avoided by using one SQL query

    A-

    So you shold follow the 2nd path described in my prev. post then...

    To answer your question (if its possible to do using TSQL) as brief as the description is: it depends. With a strong trend towards yes.



    Lutz
    A pessimist is an optimist with experience.

    How to get fast answers to your question[/url]
    How to post performance related questions[/url]
    Links for Tally Table [/url] , Cross Tabs [/url] and Dynamic Cross Tabs [/url], Delimited Split Function[/url]

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