mysql - database grouping data in tables -


i have database 3 main tables, , every of table has first 7 of 20 fields same.

for example:

table1 - a,b,c,d,e,f,g,x,y,z,df,gt,er,re,re     table2 - a,b,c,d,e,f,g,q,w,c,v,t,v,b,t,l,f     table3 - a,b,c,d,e,f,g,b,n,m,j,h,g,d,f,r,e

first fields (a,b,c,d,e,f,g) same , other different.

my question is:

  • is make 1 table fields , branching?

together_table:a,b,c,d,e,f,g

table1 - together_table_id,x,y,z,df,gt,er,re,re     table2 - together_table_id,q,w,c,v,t,v,b,t,l,f     table3 - together_table_id,b,n,m,j,h,g,d,f,r,e

or muste like: 

table1 - a,b,c,d,e,f,g,x,y,z,df,gt,er,re,re     table2 - a,b,c,d,e,f,g,q,w,c,v,t,v,b,t,l,f     table3 - a,b,c,d,e,f,g,b,n,m,j,h,g,d,f,r,e

i using mysql

together_table:a,b,c,d,e,f,g

table1 - together_table_id,x,y,z,df,gt,er,re,re     table2 - together_table_id,q,w,c,v,t,v,b,t,l,f     table3 - together_table_id,b,n,m,j,h,g,d,f,r,e

this much, better. normal form. databases designed in 3rd normal form (also written 3nf). there, start first guess , apply rules make 1nf (first normal form). apply rules of 2nf, , 3nf. there other higher normal forms required rare circumstances.


-

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