Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
It defines that no primary key value can be null. This is as the primary key is used to recognize individual tuple in the relation. So we will not be able to recognize the records uniquely containing null values for the primary key attributes. This constraint is specified on single individual relation.
Example: Let R be the Table
A#
B
C
Null
B1
C1
A2
B2
C2
B3
C3
A4
B4
A5
C5
Note:
1) '#' shows the Primary key of a relation.
In the relation R above, the primary key has null values in the tuples t1 & t3. NULL value in primary key is not allowed, therefore, relation instance is an invalid instance.
Related fields in a database are grouped in which form? Related data fields in a database are grouped to form a data record. (A record is a collection of related fields)
let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation
Outer Join: The use of Outer Join is that it still joins those tuples that do not have matching values in common columns are also contained in the result table. Outer join places
external and internal mapping with examples
Single Valued Normalisation Codd in the year 1972 formed three normal forms (1NF, 2NF, and 3NF). These were based on functional dependencies between the attributes of a relati
Determine the method of Choosing Algorithms In general, most of operations are easy and have a satisfactory algorithm since description of what is to be done also shows how i
Do NOT use the timestamp type. Use separate date and time data types only. Figure out how to define an SQL insert statement that uses built-in SQL (or MySQL) functions to define
The Structured Query Language INTRODUCTION Database is an organised set of information about an entity having controlled redundancy and serves numerous applications. DBMS
Automated system for appointment with sms and call confirmation with service providers and user has to be initiate automatically. After selecting time and date to use service, s
Support by Adding Indexes Multiple indexes can be used to access a data file by multiple access paths. In such a scheme only single copy of the data is consider, only the numbe
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd