normalization

Question

got this table from a website and trying to normalized it into 3nf but not sure if it is or not.

unitid	stdid	date	tutid	topic	room	grade	book	tutemail
u1	st1	23.02.03	tut1	GMT	629	4.7	duemlich	tut1@
u2	st1	18.11.02	tut3	Gln	631	5.1	zehnder	tut3@
u1	st4	23.02.03	tut1	GMT	629	4.3	duemlich	tut1@
u5	st2	05.05.03	tut3	phF	632	4.9	dummler	tut3@
u4	st2	04.07.03	tut5	AVQ	621	5.0	swiss topo	tut5@

there is a transitive dependency from date till tutemail.

based on my practice i made these changes to normalize it.

tbl 1 :unit id,std id, topic, grade.

tbl 2 :tutid,tutemail.

tbl 3 :unitid, book

tbl 4:Date,room

could anyone please guide me whethwe it is correct or not,

Jay Pankhaniya · Answer

It looks like you're on the right track with your attempt to normalize the table into 3NF (Third Normal Form). Let's review your proposed normalized tables: Original Table unitid stdid date tutid topic room grade book tutemail u1 st1 23.02.03 tut1 GMT 629 4.7 duemlich tut1@ u2 st1 18.11.02 tut3 Gln 631 5.1 zehnder tut3@ u1 st4 23.02.03 tut1 GMT 629 4.3 duemlich tut1@ u5 st2 05.05.03 tut3 phF 632 4.9 dummler tut3@ u4 st2 04.07.03 tut5 AVQ 621 5.0 swiss topo tut5@ Proposed Normalized Tables: Table 1: Students unitid stdid grade u1 st1 4.7 u2 st1 5.1 u1 st4 4.3 u5 st2 4.9 u4 st2 5.0 Table 2: Tutors tutid tutemail tut1 tut1@ tut3 tut3@ tut5 tut5@ Table 3: Books unitid book u1 duemlich u2 zehnder u5 dummler u4 swiss topo Table 4: Sessions date room 23.02.03 629 18.11.02 631 05.05.03 632 04.07.03 621 Your proposed normalized tables do a good job of separating the data to eliminate transitive dependencies. Each table has a clear primary key and the data is organized based on its functional dependencies. One thing to note is that the date and room information was combined in the original table and you've separated them into different tables. This separation makes sense since date and room information appear to be independent of each other.

Cr Bhargavi · Answer

Please change your table like this: I am unable to draw table like that but the pattern looks like the below Table 1: StudentResults unitid stdid date (moved to Table 4) tutid (moved to Table 2) topic room (moved to Table 4) grade book (moved to Table 3) Table 2: Tutors tutid tutemail Table 3: Books unitid book Table 4: Sessions date room

umair mohsin · Answer

thanks dear for your complete cooperation.you made my conepts more clear than before.