How to update old DB to New DB?
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From: AxisNovice on 18 Dec 2009 13:12 Hi, I understand 1. Tables to store related information and extract whenever we need it. 2. Tables should maintain data uniquely without out any data redundancy which may leads to database failure. Justification : But when the data is purely unique(having no relationship) to other fields we cannot relate to other table hence we cannot extract the data what we want. Coming to my database i have taken 3 tables, tbl_Areasdetails and course_details contains the data which is related to students.. the students table is said to be the master because I used the other 2 tables namely Areas and Courses are child table called as values from these tables as combo boxes to restrict the unknown information... I have restricted the user not to enter the erreneous information.. i have used the following sql statement to read the data from child tables.. SELECT DISTINCT tbl_AreaDetails.str_Area FROM tbl_AreaDetails; As you said the student id is not necessary in other tables so relate the table just like this.. http://sites.google.com/site/gsvfilms/Home/Students_Table_relationships_18.JPG?attredirects=0 I think important (uneditable) data should be in the tables so that we cannot lost any information regarding to a student.. Ex: If we are maintaing all tables in a single file , If any student is doing only BA degree if he has completed the course we need to delete that information. At the same time we delete the course also this make the data useless. So maintaining in other tables without any data redundancy is better .. thank you,
From: Gina Whipp on 18 Dec 2009 20:18
AxisNovice, Sorry but no, you don't understand. I can tell that by your table set-up and the fields within the table. Please review the table set-up I outlined for you in a previous post. You do not need Area and Region Belongs in two tables only one the Area table. You do not Branch in two tables only one the Courses table. As for the restriction of data entry that can be handled on the form. Storing all the information in one table is more like an Excel spreadsheet which is a flat file. Queries will be used to form a *temporary* table to get the information you need. -- Gina Whipp "I feel I have been denied critical, need to know, information!" - Tremors II http://www.regina-whipp.com/index_files/TipList.htm "AxisNovice" <prakrivi(a)xxxx.com> wrote in message news:fd4f83fc-50ac-43a5-ac05-73425268daa5(a)15g2000prz.googlegroups.com... > Hi, > > I understand > > 1. Tables to store related information and extract > whenever we need it. > > 2. Tables should maintain data uniquely without out any data > redundancy which may leads to database failure. > > Justification : > But when the data is purely unique(having no relationship) to other > fields we cannot relate to other table hence we cannot extract the > data what we want. > > Coming to my database i have taken 3 tables, tbl_Areasdetails and > course_details contains the data which is related to students.. > > the students table is said to be the master because I used the other 2 > tables namely Areas and Courses are child table called as values from > these tables as combo boxes to restrict the unknown information... > > I have restricted the user not to enter the erreneous information.. > i have used the following sql statement to read the data from child > tables.. > SELECT DISTINCT tbl_AreaDetails.str_Area FROM tbl_AreaDetails; > > As you said the student id is not necessary in other tables so relate > the table just like this.. > > http://sites.google.com/site/gsvfilms/Home/Students_Table_relationships_18.JPG?attredirects=0 > > I think important (uneditable) data should be in the tables so that we > cannot lost any information regarding to a student.. > > Ex: If we are maintaing all tables in a single file , If any student > is doing only BA degree if he has completed the course we need to > delete that information. At the same time we delete the course also > this make the data useless. So maintaining in other tables without any > data redundancy is better .. > > thank you, > |