SQL Operators are the reserve keywords, characters or symbols which are mainly used along with the WHERE clause to perform operations such as comparisons and arithmetic operations. These reserve keywords, characters or symbols are known as operators. These operators are used to specify conditions and in the conjunctions of multiple conditions in a SQL statement.
Types of SQL Operators
SQL Operators are broadly classified into the following three categories.
- SQL Arithmetic Operators.
- SQL Comparison Operators.
- SQL Logical Operators
SQL Arithmetic Operators
SQL Arithmetic operators are used to perform mathematical calculation like addition, subtraction, multiplication and division, etc. They are mainly used along with SQL Numeric data types.
Consider two variable ‘a’ and ‘b’ and value of a is 10 and value of b is 5.
| Operator | Description | Example |
| + (Addition) | Adds values on both sides of the operator. | a + b will give 15 |
| -(Substraction) | Subtracts values on right side from the value on left side of the operator. | a – b will give 5 |
| *(Multiplication) | Multiplies the values on both sides of the operator | a * b will give 50 |
| /(Division) | Divides left hand side value by right hand side value. | a/b will give 2 |
| %(Modulus) | Divides left hand side value by right hand side value and returns the reminder | a%b will give 0 |
SQL Comparison Operators
SQL Comparison operators perform comparison between two values.
Consider two variable ‘a’ and ‘b’ and value of a is 5 and value of b is 10.
| 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 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 value 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 value 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. |
SQL Logical Operators
SQL logical operators are used to perform logical operations.
Following are the list of logical operator used in SQL.
| Operator | Description |
| ALL | The ALL operator is used to compare a value to all values in another value set. |
| AND | The AND operator allows the existence of multiple conditions in an SQL statement’s WHERE clause. |
| ANY | The ANY operator is used to compare a value to any applicable value in the list as per the condition. |
| 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 a certain criterion. |
| IN | The IN operator 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. |
| 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 a 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. |
| UNIQUE | The UNIQUE operator searches every row of a specified table for uniqueness (no duplicates). |