SQL - UNION Clause

The SQL SELECT statement is used to select data from a database table and the selected data is returned in the form of a table.

Syntax

The syntax for using SELECT statement in different scenarios are given below:

/*select one column*/
SELECT column1 FROM table_name

/*select multiple columns*/
SELECT column1, column2 FROM table_name

/*select whole database table*/
SELECT * FROM table_name

Example:

Consider a database table called Employee with the following records:

• To fetch Name and Salary data of the employees present in the Employee table, the SQL code is:

  SELECT Name, Salary FROM Employee
  

  
  

  This will produce the result as shown below:

  Name	Salary
  John	3000
  Marry	2750
  Jo	2800
  Kim	3100
  Ramesh	3000
  Huang	2800




• To fetch all fields of the Employee table, the SQL code will be:

  SELECT * FROM Employee
  

  
  

  This result of the following code will be:

  EmpID	Name	City	Age	Salary
  1	John	London	25	3000
  2	Marry	New York	24	2750
  3	Jo	Paris	27	2800
  4	Kim	Amsterdam	30	3100
  5	Ramesh	New Delhi	28	3000
  6	Huang	Beijing	28	2800