how to normalize tables

[mahee]

I created three tables in one database quarterly,half_ yearly,annual respectively.
All three tables have columns like RNO,S1,S2,S3,S4 ,S5,TOTAL. Is it possible to make three table into one table.

[Stewart Ross]

We'd recommend you read our article on database normalisation and table structures which provides good guidance on what normalisation is. In your case, you have separated into three tables something (quarterly, half yearly, annual) that is simply an attribute. If the tables contain totals, it is not normally necessary to store these at all - they can be calculated by queries on the base data on demand.

Your field names are not meaningful enough to comment on whether or not the tables concerned are in any way normalised, but the fact that you have included something called S1, S2...S5 suggests they are not (it appears to be some form of repeating group, and therefore the tables concerned are not even in first normal form).

-Stewart

[Bharat383]

make field like this....
RNO,S1,S2,S3,S4 ,S5,TOTAL.
(1) time_duration varchar(100) --- > store values === quertly, half_yearly and annual
all are same...... as you defined...

while fetching data from this table make where clause like time_duration = 'quertly' for quertly