what is primary key,unique key, foreign key? can u teach me
in simple language?
- 44 Answers
- 179826 Views
- Banking, CMC, CTS, HCL, Infosys, Keggfarms, SkyEss, Sunrise, TCS, Web Synergies, Wipro, I also Faced
- E-Mail Answers
Answer Posted / navya
pk-it doesn't accept null values.there must be only one pk in table.
unique-it accept null values.there may be one r more unique keys in a table.
foreign-used to refer any key
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What is dialect in database?
How to produce such kind of file?
On startup, the transaction log of a database has filled and recovery has suspended, what can I do?
give a simple example of physical and logical data independence
Explain natural key?
What is the best database?
Under which circumstance should you create an index on a table?
What are different types of joins used in?
You are creating a Index on EMPNO column in the EMPLOYEE table. Which statement will you use?
can we delete autodiff back up that we have set through sql server agent.
WHAT IS NEED BY METION DATFMT AND TIMFMT IN H-SEPICITION IN RPGLE?
What is ole db provider for sql server?
london school of science and technology has a software development unit,known as lsst solutions,which is responsible for developing and implementing software throughout the collegejames tristan keeps a record of all student details in the college including student id,name,and start date and phone number.There are many courses offered by LSST. For example MBA, MSc, BSc, BABS, DF, English etc. Each course id identified by course id, description, duration. Each course has many semesters. Each semester takes place during a particular term. Semester details and term details are required to be stored in the database. Each course has many subjects and same subject may be offered in many courses. For each subject many details such as Subject code, name, result and attendance are required to be stored. Every subject has mainly two assessments; one assignment and one exam. Assignment is worth of 30% and exam 70% respectively. You have been appointed as a database designer. Your job is to provide ERD with all possible entities and relationships. Note: Feel free to make necessary assumptions 3: Assignment Tasks. 1. Create an ERD for the above problem 2. Translate the ERD to Relational Data model (RDM) 3. Implement the RDM by creating the tables 4. Populate the database with your own data. 5. SQL Queries for the following tasks a. List all student details in each course along with course details b. Count and display number of students in each course. c. List student name, course name, assessment description, marks for all students.
What is the concept of Virtual field?
how do you do sql tuning?
