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प्रश्न
Write any three DDL commands.
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उत्तर
- CREATE TABLE Command:
You can create a table by using the CREATE TABLE command.
CREATE TABLE Student
(Admno integer,
Name char(20), \
Gender char(1),
Age integer,
Place char(10),
); - ALTER COMMAND:
The ALTER command is used to alter the table structure like adding a column, renaming the existing column, changing the data type of any column or size of the column, or deleting the column from the table.
Alter table Student add address char; - DROP TABLE:
The drop table command is used to remove a table from the database.
DROP TABLE Student;
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संबंधित प्रश्न
The clause used to sort data in a database.
Which component of SQL lets inserts values in tables and which lets to create a table?
What is a constraint?
Write a short note on Primary key constraints.
Write a SQL statement to modify the student table structure by adding a new field.
Write a SQL statement using the DISTINCT keyword.
Consider the following employee table. Write SQL commands for the question.
| EMP CODE | NAME | DESIG | PAY | ALLO WANCE |
| S1001 | Hariharan | Supervisor | 29000 | 12000 |
| P1002 | Shaji | Operator | 10000 | 5500 |
| P1003 | Prasad | Operator | 12000 | 6500 |
| C1004 | Manjima | Clerk | 8000 | 4500 |
| M1005 | Ratheesh | Mechanic | 20000 | 7000 |
To display the details of all employees in descending order of pay.
Consider the following employee table. Write SQL commands for the question.
| EMP CODE | NAME | DESIG | PAY | ALLO WANCE |
| S1001 | Hariharan | Supervisor | 29000 | 12000 |
| P1002 | Shaji | Operator | 10000 | 5500 |
| P1003 | Prasad | Operator | 12000 | 6500 |
| C1004 | Manjima | Clerk | 8000 | 4500 |
| M1005 | Ratheesh | Mechanic | 20000 | 7000 |
To remove the employees who are mechanics.
Consider the following employee table. Write SQL commands for the question.
| EMP CODE | NAME | DESIG | PAY | ALLO WANCE |
| S1001 | Hariharan | Supervisor | 29000 | 12000 |
| P1002 | Shaji | Operator | 10000 | 5500 |
| P1003 | Prasad | Operator | 12000 | 6500 |
| C1004 | Manjima | Clerk | 8000 | 4500 |
| M1005 | Ratheesh | Mechanic | 20000 | 7000 |
To add a new row.
Construct the following SQL statement in the student table-
SELECT statement using GROUP BY clause.
