SQL Tutorial: Operators

Operators:

Two types of operators

1.    Comparison Operators

2.    Logical Operators

Comparison Operators:

Equal to	=
Greater Than	>
Less Than	<
Greater than or equal to	>=
Less than or equal to	<=
Not Equal to	<> OR! =
BETWEEN	between two Values, between an inclusive Range
LIKE	Search for a character pattern, match a character pattern
IN	If you know the exact value you want to return for at least one of the columns, Match any of a List of Values
IS NULL	Is a null value, column value does not exists

Important Notes:

1.      Comparison operators are used in WHERE clause or HAVING clause
  They compare one expression to another
  BETWEEN operator is always used with AND

    a. BETWEEN operator can be replaced by > or < operators  and  the result will be same

    b. BETWEEN operator is used with numeric data type

2.  IN can be replaced by = but the benefit of using IN is you can get multiple data of multiple values that is a list of values in one clause

a. IN operator can be used with any data type

3. LIKE operator is used to search for a character pattern when you do not the exact value you need to search for

a. The character matching search operation is referred as WILD CARD SEARCH

b. Two symbols % and _ are used to construct the search string

c.  % denotes zero or more characters for example S% means search the data for the character entry either S or any character starting from S alphabet.

d.  _  denotes any single character for example _S means search for the data whose second alphabet is S like ASAP

Logical Operators:

Combine the result of two component conditions to produce a Result

Invert the result

1. AND
2. OR
3. NOT       

AND: Both conditions should be TRUE
OR: Either condition will be True
NOT: If the condition is FALSE then it will return TRUE