Basic SELECT Statement

Topic Introduction: In this tutorial, we will show SQL's very beginning structure. Here we will use a Structure Query and give a description of the clause & functions.

SQL Structure:

SELECT *|{[DISTINCT] column|expression [alias],...}

FROM table;

SELECT identifies the columns to be displayed.

FROM identifies the table containing those columns.

In its simplest form, a SELECT statement must include the following:

A SELECT clause, which specifies the columns to be displayed

A FROM clause, which identifies the table containing the columns that are listed in the SELECT

clause

In the syntax:

SELECT is a list of one or more columns.

* Select all columns.

DISTINCT Suppresses duplicates.

column|expression Selects the named column or the expression.

alias Gives the selected columns different headings.

FROM table Specifies the table containing the columns.

Note: 

1. A keyword refers to an individual SQL element, for example, SELECT and FROM are

keywords.

2. A clause is a part of a SQL statement, for example, SELECT employee_id, last_name,

and so on.

3. A statement is a combination of two or more clauses, for example, SELECT * FROM

employees.