MySQL Tips and Functions
| • Comparison operators | |
| = | Equals |
| < | Less than |
| <= | Less than or equal to |
| > | Greater than |
| >= | Greater than or equal to |
| <> | Not equal to |
| != | Not equal to |
| LIKE | Compare strings |
| • Mathematical operators | |
| ( ) | Use parentheses to force precedence |
| + | add |
| - | subtract |
| * | multiply |
| / | divide |
| % | modulo |
| • Conditional operators | |
| || | Logical “or” |
| | | Bitwise “or” |
| OR | Same as Logical “or” |
| && | Logical “and” |
| & | Bitwise “and” |
| AND | Same as Logical “and” |
| • Some Common Functions | |
| CONCAT(str1,str2) | Concatenates strings |
| DAYNAME(date) | Returns the dayname for the given date |
| LAST_INSERT_ID( ) | Returns the last record ID inserted |
| LENGTH(column) | Returns the length of a string in characters |
| TRUNCATE(n,n) | Returns stated number of decimal places |
| UNIX_TIMESTAMP( ) | Returns the epoch |
| • Some Aggregate Functions | |
| AVG(column) | Average number from returned results |
| MAX(column) | Returns the largest number from returned results |
| MIN(column) | Returns the smallest number from returned results |
| SUM(column) | Returns the sum of all returned results |
