Database - Introduction to SQL - Discussion

Please Explain. I have Doubt.

Where is a active transformation which changes the number of rows.

I can't understand. Anyone please explain it. I too have a doubt.

Where clause is used to retrive appropriate rows from a large amount of data.

Ex: in emp table it has a 14 rows, but I want to retrive paticular data consists of emp is 7902, at taht time we use where clause. Select * from emp where emp=7902.

How can where puts a limitation on column it can only check for the conditions and display rows accordingly. The columns can only be specified with select clause.

WHERE CLAUSE ONLY LIMIT ROW NOT COLUMN
IF YOU SELECT COLUMN1, COLUMN2 IT'S SHOWS ALL ROW AND IF YOU DONE THIS WITH WHERE IT'S SHOW LIMIT ROW

Where clause provoide restriction such as how many row are retrive that specify by where clause.

Hi friends.

First of all I thank this site for giving a wonderful info about what we need exactly!

The column name (s) is the name (s) of the column which we need to retrieve the data.

We'll restrict some values which we do not need know such values are row data.

For example:.

Select emp_id, emp_name from employees.

Where emp_id IN (10, 20, 30, 40, 50) ;.

Here emp_id, emp_name are column datas and the data which we retrieve is called as row data.

So row data oly restricted.

Because in where clause we use the condition on the row tuple and not on the coloum. So b is correct ans.

In where clause we use the condition on the row tuple.