- #CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 UPDATE#
- #CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 SOFTWARE#
- #CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 FREE#
A relation R is said to be in 3NF if and only if:.No partial dependency exists between non-key attributes and key attributes. And there are no repeating elements or group of elements.Ī relation is said to be in 2NF, if and only if: – All attributes in the relation are atomic(indivisible value) Generally, in a table, we will have a lot of redundant information which is not required, so it is better to divide this complex table into multiple smaller tables which contains only unique information.Ī relation schema is in 1NF, if and only if: This helps us in removing all the redundant data. Normalization is used to decompose a larger, complex table into simple and smaller ones.
This will be the command to create a database in sql:ĬREATE DATABASE database_name. We will start off by giving the keywords DELETE FROM, then we will give the name of the table, after that we will give the WHERE clause and give the condition on the basis of which we would want to delete a row.įor example, from the employee table, if we would like to delete all the rows, where the age of the employee is equal to 25, then this will the command:Ī database is a repository in sql, which can comprise of multiple tables. We will be using the DELETE query to delete existing rows from the table: Great Learning offers career assistance and dedicated mentor support to help power ahead your career.
#CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 SOFTWARE#
You can also take up the software engineer certificate course offered by Great Learning in collaboration with leading universities. Finally, we have interview questions on two projects “ Broadband management system” and “HR DBMS”. Then, we dive into the questions of Normalization and Sub-queries. In this course, we start off with interview questions on the basics of SQL.
#CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 FREE#
To be more thorough with your preparation, do check out our Free Course on SQL Interview Questions at Great Learning Academy. We will start off by giving the keywords ALTER TABLE, then we will follow it up by giving the original name of the table, after that, we will give in the keywords RENAME TO and finally, we will give the new table name.įor example, if we want to change the “employee” table to “employee_information”, this will be the command: This is the command to change a table name in SQL: The above command will completely delete all the data present in the table along with the table itself.īut if we want to delete only the data present in the table but not the table itself, then we will use the truncate command: The DROP TABLE command is used to completely delete the table from the database. There are two ways to delete a table from sql: DROP and TRUNCATE. After that in braces, we will list out all the columns along with their datatypes.įor example, if we want to create a simple employee table: CREATE TABLE employee ( We will start off by giving the keywords, CREATE TABLE, then we will give the name of the table. The command to create a table in sql is extremely simple: CREATE TABLE table_name ( With the help of SQL, all of this data can be queried to find out valuable insights in a short span of time. For example, if a company has records of all the details of their employees in the database. This query language is evergreen and is widely used across industries.
#CLINICAL SAS INTERVIEW QUESTIONS AND ANSWERS 2017 UPDATE#
With the help of SQL, we can extract data from a database, modify this data and also update it whenever there is a requirement. It is the primary language to interact with databases. SQL stands for Structured Query Language. It is therefore absolutely essential for you to prepare yourself with the frequently asked SQL Interview questions if you want to land your dream job! There is a high demand among employers for individuals who possess SQL skills. Accessing and analyzing the data is the top most need these days and SQL enables you to do just that. Relational Databases continue to be the most extensively used database management systems.