# Operators


This page covers expression operators and commonly used control-flow and conversion functions. Precedence follows common SQL conventions: arithmetic precedes comparison, and comparison precedes logical operations. Use parentheses when in doubt.

## Arithmetic

| Operator | Meaning |
| --- | --- |
| `+` `-` `*` `/` | Addition, subtraction, multiplication, and division |
| `DIV` | Integer division |
| `%` / `MOD` | Remainder |
| Unary `-` | Negation |

## Comparison

| Operator | Meaning |
| --- | --- |
| `=` `<>` / `!=` `<` `<=` `>` `>=` | Equality and inequality comparisons |
| `BETWEEN ... AND ...` / `NOT BETWEEN` | Range test |
| `IN (...)` / `NOT IN` | Set membership |
| `IS` / `IS NOT` | Boolean comparison |
| `IS NULL` / `IS NOT NULL` / `ISNULL()` | NULL test |
| `LIKE` / `NOT LIKE` | Pattern matching. Case sensitivity follows engine configuration. |
| `ILIKE` | Case-insensitive pattern matching |
| `COALESCE()` | Returns the first non-NULL argument |

Comparing `NULL` with any value by using `=` never produces TRUE. Use `IS NULL` to test for NULL.

## Logical

| Operator | Meaning |
| --- | --- |
| `AND` / `&&` | AND |
| `OR` | OR |
| `XOR` | Exclusive OR |
| `NOT` / `!` | NOT |

## Bitwise

| Operator | Meaning |
| --- | --- |
| `&` `\|` `^` | Bitwise AND / OR / XOR |
| `<<` `>>` | Left / right shift |
| `~` | Bitwise NOT |

## Assignment

| Operator | Meaning |
| --- | --- |
| `=` | Assignment in contexts such as `SET`. It has the same form as comparison `=`, and context determines the meaning. |

## Type conversion

| Function / operator | Meaning |
| --- | --- |
| `CAST(expr AS type)` | Explicit conversion |
| `CONVERT(expr, type)` | Explicit conversion, commonly used for date-time and decimal values |
| `BINARY` | Converts to binary-string semantics |
| `ENCODE` / `DECODE` / `SERIAL` / `SERIAL_FULL`, and others | Encoding and serialization operations, subject to version support |

## Control flow

| Form | Meaning |
| --- | --- |
| `CASE WHEN ... THEN ... ELSE ... END` | Multiple branches |
| `IF(cond, a, b)` | Selects one of two values based on a condition |
| `IFNULL(a, b)` | Returns b when a is NULL |
| `NULLIF(a, b)` | Returns NULL when a equals b; otherwise returns a |

## INTERVAL

Date operations use `INTERVAL` to express a time interval, together with `DATE_ADD` / `DATE_SUB` or literal operations. Units include the common set of `DAY`, `HOUR`, `MINUTE`, `SECOND`, `MONTH`, and `YEAR`.

```sql
SELECT DATE_ADD(NOW(), INTERVAL 1 DAY);
```