Update salary based on average salary : Update « Insert Update Delete « Oracle PL/SQL Tutorial

SQL>
SQL>
SQL>
SQL> create table emp(
  2           emp_no                 integer         primary key,
  3           lastname               varchar2(20)    not null,
  4           firstname              varchar2(15)    not null,
  5           midinit                varchar2(1),
  6           street                 varchar2(30),
  7           city                   varchar2(20),
  8           state                  varchar2(2),
  9           zip                    varchar2(5),
 10           shortZipCode                   varchar2(4),
 11           area_code              varchar2(3),
 12           phone                  varchar2(8),
 13           salary                 number(5,2),
 14           birthdate              date,
 15           startDate              date,
 16           title                  varchar2(20),
 17           dept_no                integer,
 18           mgr                    integer,
 19           region                 number,
 20           division               number,
 21           total_sales            number
 22  );

Table created.

SQL> -- emp Table Inserts:
SQL> insert into emp(emp_no, lastname, firstname, midinit, street, city, state, zip,shortZipCode, area_code, phone, birthdate, title)values
  2                      (1,'Z','Joy','R','1 Ave','New York','NY','12122','2333','212','200-1111','12-nov-1962','President');

1 row created.

SQL> insert into emp(emp_no, lastname, firstname, midinit, street, city, state, zip,shortZipCode, area_code, phone, salary, birthdate, startDate,title, dept_no, mgr, region, division, total_sales)valu
es
  2                      (2,'X','Lucy','J','1 Street','New York','NY','43552','6633','212','234-4444',7.75,'21-mar-1976','1-feb-1994','Sales Manager',2,1,100,10,40000);

1 row created.

SQL> insert into emp(emp_no, lastname, firstname, midinit, street, city, state, zip,shortZipCode, area_code, phone, salary, birthdate, startDate,title, dept_no, mgr, region, division, total_sales)valu
es
  2                      (3,'Y','Jordan','E','1 Drive','New York','NY','76822','8763','212','222-2222',7.75,'14-feb-1963','15-mar-1995','Sales Clerk',2,2,100,10,10000);

1 row created.

SQL>
SQL> select dept_no, lastname, salary from emp;

   DEPT_NO LASTNAME                 SALARY
---------- -------------------- ----------
           Z
         2 X                          7.75
         2 Y                          7.75

SQL>
SQL> UPDATE emp e1
  2     SET salary = 1.1 * (SELECT avg(salary) from emp e2 where e1.dept_no = e2.dept_no);

3 rows updated.

SQL>
SQL>
SQL> drop table emp;

Table dropped.

4.3.Update
	4.3.1.	Modifying Rows Using the UPDATE Statement
	4.3.2.	Change more than one column value in update statement
	4.3.3.	If the WHERE clause were omitted, all the rows would be updated.
	4.3.4.	Change multiple rows and multiple columns in the same UPDATE statement
	4.3.5.	Use function in set clause
	4.3.6.	Writing an UPDATE Statement Containing a Subquery
	4.3.7.	Use TO_DATE('December 31, 2005, 11:30 P.M.','Month dd, YYYY, HH:MI P.M.') in update statement
	4.3.8.	Set clause with math expression
	4.3.9.	Update with subquery
	4.3.10.	Update a subquery
	4.3.11.	Set value based on a select statement
	4.3.12.	Change department name to lower case
	4.3.13.	Update data from existing column
	4.3.14.	Update four columns
	4.3.15.	Update one row
	4.3.16.	Update salary based on average salary
	4.3.17.	Update the emp table, converting emp names to uppercase
	4.3.18.	subquery in update statement
	4.3.19.	To update the salary of all emps to the maximum salary in the corresponding department (correlated subquery):