Admin

Alter Table Statement  Definition : Alter Table statement is used to change the structure of an existing table of a database i.e. this statement specifies how to add one or multiple new columns/fields/attributes, modify one or more existing columns/fields/attributes , drop or delete the existing columns from a table, rename Read more…

Definition : This statement is used to modify/change/update the existing record/s or data in the database. Syntax : UPDATE table–name SET(column–name1=value1, column–name2 =value2, column–name3=value3, column–name4=value4, column–name5=value5 ) ; Example : UPDATE employee SET(emp_id=”125M”, emp_name=”Rahman”, emp_addr =”Kolkata”, emp_dept=”Manager”, emp_dob=”05/22/2020″, emp_sal=20500, emp_mob=9334582186); UPDATE employee SET(emp_name=”Rahman”, emp_addr =”Kolkata”, emp_dept=”Manager”, emp_dob=”05/22/2020″, emp_sal=20500, emp_mob=9334582186 where emp_id= “105M”);

Definition :  This statement is used to remove one or more records permanently from the database table. Syntax :  DELETE table-name; DELETE table-name where condition; Example :  Problem : How to remove all data/records from a table permanently. SQL> Delete from employee; SQL> Delete * from employee; Problem : How Read more…

SELECT STATEMENT Basic Select Syntax :  SELECT column_name1,column_name2… column_name_n FROM table-name[WHERE Clause][GROUP BY clause][HAVING clause][ORDER BY clause]; The SELECT query statement is used to retrieve stored data from a database in the form of table-like structure called result set. It is one of the largest use query/statement.            Example : How Read more…