oracle - SQL: Repeating data in JOIN -


i'm doing homework class , can't figure out how answer question:

"determine books generate less 55% profit , how many copies of these books have been sold. summarize findings management, , include copy of query used retrieve data database tables."

i tried taking shot @ can't seem come out way want to. has data doesn't seem go together. below code:

select isbn, b.title, b.cost, b.retail, o.quantity "# of times ordered",    round(((retail-cost)/retail)*100,1)||'%' "percent profit",     o.quantity "# of times ordered" books o join orderitems o using(isbn);

it works in sense data need comes this:

enter image description here

i have theory because table "order items" has multiple orders same isbn , different quantities it's selecting of them. there way combine them? if not me rid of redundant data caused join?

thank you!

i've had similar things in sql server / mysql. need group columns in see repeated data not care about, , need sum field values important you, this...

select isbn, b.title, b.cost, b.retail, o.quantity "# of times ordered",    round(((retail-cost)/retail)*100,1)||'%' "percent profit",     sum(o.quantity) "# of times ordered" books o join orderitems o using(isbn) group isbn, b.title, b.cost, b.retail;

if need more information, go here , search sum: https://docs.oracle.com/javadb/10.6.1.0/ref/rrefsqlj32654.html


-

Popular posts from this blog

c# - ODP.NET Oracle.ManagedDataAccess causes ORA-12537 network session end of file -

overview i want replace oracle.dataaccess orcale. managed dataaccess, opening connection latter throws ora-12537 network session end of file exception. exception message / stack trace {oracleinternal.network.networkexception (0x000030f9): ora-12537 : netzwerksession: dateiende @ oracleinternal.network.readerstream.read(orabuf ob) @ oracleinternal.ttc.orabufreader.getdatafromnetwork() @ oracleinternal.ttc.orabufreader.read(boolean bignoredata) @ oracleinternal.ttc.marshallingengine.unmarshalub1(boolean bignoredata) @ oracleinternal.ttc.ttcprotocolnegotiation.readresponse()} i trying connect oracle 11g database , not have client installed on local machine. working test application (unmanaged) using oracle.dataaccess works fine . using system; using oracle.dataaccess.client; namespace app.odp.unmanaged { internal class program { private static void main(string[] args) { //dummy connection string
Read more

matlab - Compression and Decompression of ECG Signal using HUFFMAN ALGORITHM -

i want compress , decompress ecg signal stored text message text file , find out file size, cr,prd ratio,and qs. here code compression , decompression of ecg signal using huffman algorithm. i'm trying find out file size, compression ratio,prd ratio,qs. but error i'm getting the ecg file in text format. %clearing variables , screen enter code here clear all; close all; clc; [file1]=uigetfile('*.txt'); %fprintf('enter ecg file name :%s',file1); p=file1; t=sprintf('%s',p); b1=dlmread([file1]); len=length(b1); lead=input('enter lead number :'); %lead=str2double(lead); col2=b1(1:end,lead); e=fix(sqrt(len)); m=1; i=1:e j=1:e g2(i,j)=fix(col2(m)*1000); %amplifying 1000 m=m+1; end end g3=g2; i=1:e j=1:e
Read more

utf 8 - split utf-8 string into bytes in python -

i trying split utf-8 string bytes in python 3. problem is, when use bytearray, byte, encode etc functions array size of element 14 bytes, not 1 byte expected. need split text file sequence of bytes , send them byte after byte using sockets. tried this: infile = open (file, "r") str = infile.read() byte_str = bytes(str, 'utf-8') print("size of byte_str",sys.getsizeof(byte_str[0])) print gives me 14, need 1... suggestion? quoting official documentation : sys.getsizeof(object[, default]) return size of object in bytes. object can type of object. built-in objects return correct results, not have hold true third-party extensions implementation specific. only memory consumption directly attributed object accounted for, not memory consumption of objects refers to. if given, default returned if object not provide means retrieve size. otherwise typeerror raised. getsizeof() calls object’s __sizeof__ method , adds
Read more