Operators are used to build
expressions. SQL operators are very similar to mathematical operators. SQLite
supports unary and binary operators. Binary operators work with two operands,
unary work with one. An operator may have one or two operands. An operand is
one of the inputs (arguments) of an operator.
SQLite supports five broad categories of
operators:
·
Arithmetic operators
·
Comparison operators
·
Logical operators
·
Bitwise operators
SQLite
Arithmetic Operators:
Assume
variable a holds 20 and variable b holds 40, then:
Operator |
Description |
Example |
+ |
Addition -
Adds values on either side of the operator |
a + b will
give 60 |
- |
Subtraction
- Subtracts right hand operand from left hand operand |
a - b will
give -20 |
* |
Multiplication
- Multiplies values on either side of the operator |
a * b will
give 800 |
/ |
Division -
Divides left hand operand by right hand operand |
b / a will
give 2 |
% |
Modulus -
Divides left hand operand by right hand operand and returns remainder |
b % a will
give 0 |
SQLite
Comparison Operators:
Assume
variable a holds 20 and variable b holds 40, then:
Operator |
Description |
Example |
== |
Checks if
the values of two operands are equal or not, if yes then condition becomes
true. |
(a == b)
is not true. |
= |
Checks if
the values of two operands are equal or not, if yes then condition becomes
true. |
(a = b) is
not true. |
!= |
Checks if
the values of two operands are equal or not, if values are not equal then
condition becomes true. |
(a != b)
is true. |
<> |
Checks if
the values of two operands are equal or not, if values are not equal then
condition becomes true. |
(a
<> b) is true. |
> |
Checks if
the values of left operand is greater than the value of right operand, if yes
then condition becomes true. |
(a > b)
is not true. |
< |
Checks if
the values of left operand is less than the value of right operand, if yes
then condition becomes true. |
(a < b)
is true. |
>= |
Checks if
the value of left operand is greater than or equal to the value of right
operand, if yes then condition becomes true. |
(a >=
b) is not true. |
<= |
Checks if
the value of left operand is less than or equal to the value of right
operand, if yes then condition becomes true. |
(a <=
b) is true. |
!< |
Checks if
the value of left operand is not less than the value of right operand, if yes
then condition becomes true. |
(a !<
b) is false. |
!> |
Checks if
the value of left operand is not greater than the value of right operand, if
yes then condition becomes true. |
(a !>
b) is true. |
SQLite
Logical Operators:
Here is a
list of all the logical operators available in SQLite.
Operator |
Description |
AND |
The AND
operator allows the existence of multiple conditions in an SQL statement's
WHERE clause. |
BETWEEN |
The
BETWEEN operator is used to search for values that are within a set of
values, given the minimum value and the maximum value. |
EXISTS |
The EXISTS
operator is used to search for the presence of a row in a specified table
that meets certain criteria. |
IN |
The IN
operator is used to compare a value to a list of literal values that have
been specified. |
NOT IN |
The
negation of IN operator which is used to compare a value to a list of literal
values that have been specified. |
LIKE |
The LIKE
operator is used to compare a value to similar values using wildcard
operators. |
GLOB |
The GLOB
operator is used to compare a value to similar values using wildcard
operators. Also, GLOB is case sensitive, unlike LIKE. |
NOT |
The NOT
operator reverses the meaning of the logical operator with which it is used.
Eg. NOT EXISTS, NOT BETWEEN, NOT IN, etc. This is negate operator. |
OR |
The OR
operator is used to combine multiple conditions in an SQL statement's WHERE
clause. |
IS NULL |
The NULL
operator is used to compare a value with a NULL value. |
IS |
The IS
operator work like = |
IS NOT |
The IS
operator work like != |
|| |
Adds two
different strings and make new one. |
UNIQUE |
The UNIQUE
operator searches every row of a specified table for uniqueness (no
duplicates). |
SQLite
Bitwise Operators:
Decimal
numbers are natural to humans. Binary numbers are native to computers. Binary,
octal, decimal, or hexadecimal symbols are only notations of the same number.
Bitwise operators work with bits of a binary number. We have binary logical
operators and shift operators.
Bitwise
operator works on bits and perform bit-by-bit operation. The truth table for
& and | is as follows:
p |
q |
p &
q |
p | q |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
1 |
1 |
1 |
1 |
1 |
1 |
0 |
0 |
1 |
Assume if A
= 60; and B = 13; now in binary format, they will be as follows:
A = 0011
1100
B = 0000
1101
-----------------
A&B =
0000 1100
A|B = 0011
1101
~A =
1100 0011
The Bitwise
operators supported by SQLite language are listed in the following table.
Assume variable A holds 60 and variable B holds 13, then:
Show
Examples
Operator |
Description |
Example |
& |
Binary AND
Operator copies a bit to the result if it exists in both operands. |
(A &
B) will give 12 which is 0000 1100 |
| |
Binary OR
Operator copies a bit if it exists in either operand. |
(A | B)
will give 61 which is 0011 1101 |
~ |
Binary
Ones Complement Operator is unary and has the effect of 'flipping' bits. |
(~A ) will
give -61 which is 1100 0011 in 2's complement form due to a signed binary
number. |
<< |
Binary
Left Shift Operator. The left operands value is moved left by the number of
bits specified by the right operand. |
A <<
2 will give 240 which is 1111 0000 |
>> |
Binary
Right Shift Operator. The left operands value is moved right by the number of
bits specified by the right operand. |
A >>
2 will give 15 which is 0000 1111 |