INSERT, UPDATE and DELETE Statement in SQl

Data Manipulation Language 

INSERT STATEMENT:

                             The INSERT statement is used to add new row in database table. 

 INSERT Type 1:

                INSERT IINTO Table_name Values(column1_value,column2_value,column3_value,______)

 In this type values insert into all column in table.

Employee

id	Emp_name	Age	Salary	Dept_id
1	Jebas	35	80000	2
2	Thomas	30	40000	1
3	Mark	25	40000	2
4	Harry	42	62500	2
5	Willam	45	125000	1
6	James	32	35000	3
7	Mock	22	15000	3

INSERT INTO Employee VALUES('Sherin',23,14000,7);

Employee

id	Emp_name	Age	Salary	Dept_id
1	Jebas	35	80000	2
2	Thomas	30	40000	1
3	Mark	25	40000	2
4	Harry	42	62500	2
5	Willam	45	125000	1
6	James	32	35000	3
7	Mock	22	15000	3
8	Sherin	23	12000	7

INSERT TYPE 2.

                 INSERT INTO Table_name (column1,column2, column3_____) Values(column1_value,column2_value,column3_value,______)

In this type the value insert only specified column in table.

INSERT INTO Employee (Emp_name,Age,salary,dept_id) VALUES('MOSES',26,20000,6);

Employee

id	Emp_name	Age	Salary	Dept_id
1	Jebas	35	80000	2
2	Thomas	30	40000	1
3	Mark	25	40000	2
4	Harry	42	62500	2
5	Willam	45	125000	1
6	James	32	35000	3
7	Mock	22	15000	3
8	Sherin	23	12000	7
9	MOSES	26	20000	6

UPDATE STATEMENT:

                                        The update statement will update or modify one or more column in database table. The update is used along with where clause to update only specified column.

UPDATE table_name SET Column=value WHERE Condition

In this type, it update only one column.

UPDATE Employee SET salary=21000 where id=9;

UPDATE table_name SET Column1=value, Column2=value,

Column3=value,____WHERE Condition.

UPDATE Employee SET salary=23000,dept_id=4 where id=9

In this type, it update multiple column at one time.

Employee

id	Emp_name	Age	Salary	Dept_id
1	Jebas	35	80000	2
2	Thomas	30	40000	1
3	Mark	25	40000	2
4	Harry	42	62500	2
5	Willam	45	125000	1
6	James	32	35000	3
7	Mock	22	15000	3
8	Sherin	23	12000	7
9	MOSES	26	23000	4

Be careful when update statement, when update without where condition

UPDATE Employee set emp_name='jebas';

It will update all emp_name to jebas.😀;

DELETE STATEMENT.

                                    The DELETE Statement used to delete record or row from database table.

DELETE table_name WHERE Column_value CONDITION

DELETE From Employee WHERE id=8;

This delete statement will remove entire row of id=8;

Employee

id	Emp_name	Age	Salary	Dept_id
1	Jebas	35	80000	2
2	Thomas	30	40000	1
3	Mark	25	40000	2
4	Harry	42	62500	2
5	Willam	45	125000	1
6	James	32	35000	3
7	Mock	22	15000	3
9	MOSES	26	23000	4

The DELETE statement without where class will delete entire table.

DELETE FROM Employee;

Employee

id

Emp_name

Age

Salary

Dept_id

DROP Statement.

                     The DROP Statement will delete the entire table itself.

DROP Table_name;

DROP Employee.

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