1.SQL statements are not case sensitive. SELECT is the same as select.
2. SELECT Statement Syntax:
SELECT column_name(s) FROM table_name
SELECT LastName,FirstName FROM Persons
SELECT * FROM Persons
The SELECT DISTINCT Statement:
*The DISTINCT keyword is used to return only distinct (different) values.
The SELECT statement returns information from table columns. But what if we only want to select distinct elements?
With SQL, all we need to do is to add a DISTINCT keyword to the SELECT statement:SELECT DISTINCT column_name(s) FROM table_name
3.WHERE
With the WHERE clause, the following operators can be used:
= Equal
<> Not equal !=
> Greater than
< Less than
>= Greater than or equal
<= Less than or equal
BETWEEN Between an inclusive range
LIKE Search for a pattern
A "%" sign can be used to define wildcards (missing letters in the pattern) both before and after the pattern.
SELECT * FROM Persons WHERE FirstName LIKE '%la%'
NOTE: Using Quotes
SQL uses single quotes around text values (most database systems will also accept double quotes). Numeric values should not be enclosed in quotes.