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Question
Consider the table Personal given below:
| Table: Personal | ||||
| P_ID | Name | Desig | Salary | Allowance |
| P01 | Rohit | Manager | 89000 | 4800 |
| P02 | Kashish | Clerk | NULL | 1600 |
| P03 | Mahesh | Superviser | 48000 | NULL |
| P04 | Salil | Clerk | 31000 | 1900 |
| P05 | Ravina | Superviser | NULL | 2100 |
Based on the given table, write SQL queries for the following:
- Increase the salary by 5% of personals whose allowance is known.
- Display Name and Total Salary (sum of Salary and Allowance) of all personals. The column heading ‘Total Salary’ should also be displayed.
- Delete the record of Supervisors who have salary greater than 25000.
Solution
- UPDATE Personal
SET Salary=Salary*0.5
WHERE Allowance IS NOT NULL; - SELECT Name, Salary+Allowance AS
"Total Salary" FROM Personal; - DELETE FROM Personal
WHERE Salary>25000
APPEARS IN
RELATED QUESTIONS
Each table comprises of ______ and ______.
Case Based
Consider the table STUDENT with the following detail.
| STU_ID | NAME | STREAM | MARKS | CLASS |
| 1. | Aditya | Science | 87.5 | 12A |
| 2. | Vikram | Commerce | 88.7 | 12B |
| 3. | Astha | Humanities | 76.8 | 12C |
| 4. | Varsha | Science | 79.5 | 12A |
| 5. | Kanishka | Science | 77.9 | 12A |
| 6. | Anand | Commerce | 86.7 | 12B |
Now answer the question given below:
Command to select all Science students from the table STUDENT
Case Based
Consider the table STUDENT with the following detail.
| STU_ID | NAME | STREAM | MARKS | CLASS |
| 1. | Aditya | Science | 87.5 | 12A |
| 2. | Vikram | Commerce | 88.7 | 12B |
| 3. | Astha | Humanities | 76.8 | 12C |
| 4. | Varsha | Science | 79.5 | 12A |
| 5. | Kanishka | Science | 77.9 | 12A |
| 6. | Anand | Commerce | 86.7 | 12B |
Now answer the question given below:
Delete records that belongs to 'Humanities' stream.
Which of the following is not an RDBMS?
Which of the following are included in defining a schema?
To know the names of existing databases, we use the statement:
What statement will you give to view the structure of a table?
To remove an attribute or to add a constraint to an already existing table we use:
How will you add a primary key to a relation?
Which statement is used to remove a table from the database?
Raju's date of birth is 21/06/2006. How will his date be added to database?
Differentiate between the following statement:
ALTER and UPDATE
Suppose your school management has decided to conduct cricket matches between students of Class XI and Class XII. Students of each class are asked to join any one of the four teams – Team Titan, Team Rockers, Team Magnet, and Team Hurricane. During summer vacations, various matches will be conducted between these teams. Help your sports teacher to do the following:
- Create a database “Sports”.
- Create a table “TEAM” with the following considerations:
i) It should have a column TeamID for storing an integer value between 1 to 9, which refers to the unique identification of a team.
ii) Each TeamID should have its associated name (TeamName), which should be a string of length not less than 10 characters. - Using table level constraint, make TeamID the primary key.
- Show the structure of the table TEAM using a SQL statement.
- As per the preferences of the students four teams were formed as given below. Insert these four rows in the TEAM table:
Row 1: (1, Team Titan)
Row 2: (2, Team Rockers)
Row 3: (3, Team Magnet)
Row 3: (4, Team Hurricane) - Show the contents of the table TEAM using a DML statement.
- Now create another table MATCH_DETAILS and insert data as shown below. Choose appropriate data types and constraints for each attribute.
| Table: MATCH_DETAILS | |||||
| MatchID | MatchDate | FirstTeamID | SecondTeamID | FirstTeamScore | SecondTeamScore |
| M1 | 2018-07-17 | 1 | 2 | 90 | 86 |
| M2 | 2018-07-18 | 3 | 4 | 45 | 48 |
| M3 | 2018-07-19 | 1 | 3 | 78 | 56 |
| M4 | 2018-07-19 | 2 | 4 | 56 | 67 |
| M5 | 2018-07-18 | 1 | 4 | 32 | 87 |
| M6 | 2018-07-17 | 2 | 3 | 67 | 51 |
______ command is used to remove the primary key from a table in SQL.
______ is a non-key attribute, whose values are derived from the primary key of some other table.
To establish a connection between Python and SQL databases, connect() is used. Which of the following arguments may not necessarily be given while calling connect()?
Write the command to view all tables in a database.
The code given below reads the following record from the table named student and displays only those records that have marks greater than 75:
- RollNo - integer
- Name - string
- Clas - integer
- Marks - integer
Note the following to establish connectivity between Python and MYSQL:
- Username is root.
- The password is the tiger.
- The table exists in an MYSQL database named school.
Write the following missing statements to complete the code:
Statement 1 - to form the cursor object
Statement 2 - to execute the query that extracts records of those students whose marks are greater than 75.
Statement 3 - to read the complete result of the query (records whose marks are greater than 75) into the object named data, from the table student in the database.
import mysql.connector as mysql
def sql_data():
con1=mysql.connect(host="localhost",user="root",password="tiger", database="school")
mycursor=_______________ #Statement 1
print("Students with marks greater than 75 are :")
_________________________ #Statement 2
data=__________________ #Statement 3
for i in data:
print(i)
print()Write the command to view all databases.
Name any two DDL commands.
The code given below deletes the record from the table employee, which contains the following record structure:
E_code - StringE_name - StringSal - IntegerCity - String
Note the following to establish connectivity between Python and MySQL:
- Username is
root - Password is
root - The table exists in a MySQL database named
emp. - The details
(E_code, E_name, Sal, City)are the attributes of the table.
Write the following statements to complete the code:
Statement 1 – to import the desired library.
Statement 2 – to execute the command that deletes the record with E_code as 'E101'.
Statement 3 – to delete the record permanently from the database. ____________
import ____________ as mysql #Statement1
def delete():
mydb=mysql.connect(host="localhost",use r="root",
passwd="root",database="emp")
mycursor=mydb.cursor()
____________ #Statement 2
____________ #Statement 3
print ("Record deleted") Ms Shalini has just created a table named “Employee” containing columns Ename, Department and Salary. After creating the table, she realized that she has forgotten to add a primary key column in the table. Help her in writing an SQL command to add a primary key column EmpId of integer type to the table Employee.
Thereafter, write the command to insert the following record in the table:
EmpId- 999
Ename- Shweta
Department: Production
Salary: 26900