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Renewal·서른의 생활코딩

Day 9) Comparison / Logical / Other Operators

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select *

from prod;


select *

from prod

order by prod_sale desc, prod_lgu, prod_name asc;


--21.p

-- Find products with sale price of 170,000 won

select prod_name ProductName

        , prod_sale SalePrice

from prod

where prod_sale = 170000;



-- Find products above or below 170,000 won

select prod_name ProductName

        , prod_sale SalePrice

from prod

where prod_sale < 170000;


select prod_name 

        , prod_sale SalePriceProductName

from prod

where prod_sale > 170000;


-- Find products at or above, or at or below 170,000 won

select prod_name ProductName

        , prod_sale SalePrice

from prod

where prod_sale <= 170000;


select prod_name ProductName

        , prod_sale SalePrice

from prod

where prod_sale <> 170000; -- not equal



select  prod_id "ProductCode" -- when spaces are needed... 

        , prod_name "ProductName" -- but since it ties to variable names, use English with no spaces 

        , prod_cost "CostPrice"

from prod

where prod_cost <=200000;



select mem_id MemberID

        , mem_name MemberName

        , mem_regno1 RegNoFront

from member

--where mem_regno1 >= 760101;    -- string:number  --- auto cast -> number:number

where mem_regno1 >= '760101';    -- string:string   

                                 -- date takes precedence over string, 

                                 -- date:string(/-.) --- auto cast -> date:date 


desc member; -- find data type 




select prod_name Product

        , prod_lgu ProductCategory

        , prod_sale SalePrice 

from prod;




select prod_name Product

        , prod_lgu ProductCategory

        , prod_sale SalePrice 

from prod

where prod_lgu='P201' 

and prod_sale=17000;



select prod_name Product

        , prod_lgu ProductCategory

        , prod_sale SalePrice 

from prod

where prod_lgu='P201' 

or prod_sale=17000;


select prod_name Product

        , prod_lgu ProductCategory

        , prod_sale SalePrice 

from prod

where 

not prod_sale=17000;



select prod_name

        , prod_lgu

        , prod_sale

from prod

where prod_lgu<>'P201' and prod_sale<>170000;



select prod_name

        , prod_lgu

        , prod_sale

from prod

where prod_lgu !='201'

and prod_sale !=170000;




-- De Morgan's law applied

select prod_name

        , prod_lgu

        , prod_sale

        

from prod

where not(prod_lgu ='P201'

or prod_sale =170000);-- De Morgan's law applied




select prod_id ,ProductCode

        ,prod_name ProductName

        ,prod_sale Price

from prod

where prod_sale betenn >=300000

and prod_sale <= 50000;




SELECT  *

FROM member

where mem_job='CivilServant' and mem_mileage>=1500;



select prod_name ProductName

        ,prod_id ProductCode

        ,prod_sale ProductPrice

from prod

--where prod_sale=150000 or prod_sale=170000 or prod_sale=330000;

where prod_sale in(15000,17000,330000) and prod_cost > 100000

order by prod_sale asc, prod_sale asc, prod_sale asc;



select mem_id

        ,mem_name

from member

where mem_id in('c001','f001','w001');



--select * from lprod;

--select * from prod;

--select distinct prod_lgu;  -- does this exist?


select lprod_id

        ,lprod_nm

from lprod

where lprod_gu in( --main SQL

    select distinct prod_lgu --main SQL

    from prod); 

    


select lprod_id

        ,lprod_nm

from lprod

where lprod_gu not in

(select distinct prod_lgu from prod);

    

        

select buyer_id

        ,buyer_name

from buyer

where buyer_id in

(select distinct prod_buyer from prod);



select *

from prod

where prod_price between 100000 and 300000; -- range "from X up to Y" 



select mem_id

        , mem_name

        , mem_bir

from member

where mem_bir between '19750101' and '19761231';



select prod_name

        , prod_cost

        , prod_sale

from prod

--where (prod_cost between 300000 and 15000000) -- same as below

--and (prod_sale between 800000 and 20000000);

where prod_cost between 300000 and 15000000

--where prod_cost between to_member('300,000','15,000,000') -- can also be declared separately

and prod_sale between 800000 and 20000000;



select mem_id

        , mem_name

        , mem_bir

        , to_char(mem_bir,'yyyy-mm-dd')  -- adjust output format 

from member

--where not mem_bir between '1975/01/01' and '1975/12/31';  -- same as below, not position

--where mem_bir not between '1975/01/01' and '1975/12/31';  -- same as below

--where mem_bir not between '1975-01-01' and '1975-12-31';  -- same as below

where mem_bir not between '19750101' and '19751231';




 

    




https://www.w3schools.com/sql/sql_like.asp

This English version was translated by Claude.

친절한 찰쓰씨
Written by
친절한 찰쓰씨

Pleasant Charles — UI/UX researcher at AIT. Keeping notes on design, planning, and slow days here since 2010.

More on the author's page

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