Page 51 - DCAP402_DCAO204_DATABASE MANAGEMENT SYSTEM_MANAGING DATABASE

Database Management Systems/Managing Database

Notes Step I
Cross product of E and D
Step II
Apply qualification condition

E.eid = D.Dept_managerid AND
D.Dname = ‘Accounts’ to the cross product table and select second and sixth row.
Step III
Discard all the unwanted columns and the result contains only the ename field.

Result of Step-II

Hid Ename D.No. Esal Age Phone DepLManagerid D.No. D.Natne D .Location P.No.
101 John 2 35000 50 24578912 101 2 Accounts Secunderabad 11
97 Harry 5 30000 41 23535135 97 5 Accounts Hyderabad 22

Result of Step-III

Ename
John

Harry
This indicates that John and Harry are the employees whose department name is ‘Accounts’.

Task In DBMS when you can use WHERE clause.

3.6 Creating Tables

The create table statement is used to create a new table. Here is the format of a simple create
table statement:
create table “tablename”
(“column1” “data type”,

“column2” “data type”,
“column3” “data type”);
Format of create table if you were to use optional constraints:
create table “tablename”
(“column1” “data type”

[constraint],
“column2” “data type”
[constraint],

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