MariaDB – Useful Functions
This chapter contains a list of the most frequently used functions, offering definitions, explanations, and examples.
MariaDB Aggregate Functions
Most frequently used aggregate functions are given below −
| Sr.No | Name & Description | 
|---|---|
| 1 | 
 COUNT It counts the number of records. Example − SELECT COUNT(*) FROM customer_table;  | 
| 2 | 
 MIN It reveals the minimum value of a set of records. Example − SELECT organization, MIN(account) FROM contracts GROUP BY organization;  | 
| 3 | 
 MAX It reveals the maximum value of a set of records. Example − SELECT organization, MAX(account_size) FROM contracts GROUP BY organization;  | 
| 4 | 
 AVG It calculates the average value of a set of records. Example − SELECT AVG(account_size) FROM contracts;  | 
| 5 | 
 SUM It calculates the sum of a set of records. Example − SELECT SUM(account_size) FROM contracts;  | 
MariaDB Age Calculation
The TIMESTAMPDIFF function provides a way to calculate age −
SELECT CURDATE() AS today; SELECT ID, DOB, TIMESTAMPDIFF(YEAR,DOB,''2015-07-01'') AS age FROM officer_info;
MariaDB String Concatenation
The CONCAT function returns the resulting string after a concatenation operation. You can utilize one or more arguments. Review its syntax given below −
SELECT CONCAT(item, item,...);
Review the following example −
SELECT CONCAT(''Ram'', ''bu'', ''tan'');
Output:Rambutan
MariaDB Date/Time Functions
Given below are important date functions −
| Sr.No | Name & Description | 
|---|---|
| 1 | 
 CURDATE() It returns the date in yyyy-mm-dd or yyyymmdd format. Example − SELECT CURDATE();  | 
| 2 | 
 DATE() It returns the date in multiple formats. Example −CREATE TABLE product_release_tbl (x DATE);  | 
| 3 | 
 CURTIME() It returns the time in HH:MM:SS or HHMMSS.uuuuuu format. Example − SELECT CURTIME();  | 
| 4 | 
 DATE_SUB() It adds or subtracts a number of days from the specified date. Example − SELECT DATE_SUB(”2016-02-08”, INTERVAL 60 DAY);  | 
| 5 | 
 DATEDIFF() It determines the days between two dates. Example − SELECT DATEDIFF(”2016-01-01 23:59:59”,”2016-01-03”);  | 
| 6 | 
 DATE ADD() It adds or subtracts any unit of time to/from the date and time. Example − SELECT DATE_ADD(”2016-01-04 23:59:59”, INTERVAL 22 SECOND);  | 
| 7 | 
 EXTRACT() It extracts a unit from the date. Example − SELECT EXTRACT(YEAR FROM ”2016-01-08”);  | 
| 8 | 
 NOW() It returns the current date and time in either yyyy-mm-dd hh:mm:ss or yyyymmddhhmmss.uuuuuu format. Example − SELECT NOW();  | 
| 9 | 
 DATE FORMAT() It formats the date in accordance with the specified format string. Example − SELECT DATE_FORMAT(”2016-01-09 20:20:00”, ”%W %M %Y”);  | 
Following are some important time functions −
| Sr.No | Name & Description | 
|---|---|
| 1 | 
 HOUR() It returns the hour of the time, or the hours elapsed. Example − SELECT HOUR(”19:17:09”);  | 
| 2 | 
 LOCALTIME() It functions exactly like NOW().  | 
| 3 | 
 MICROSECOND() It returns the microseconds of the time. Example − SELECT MICROSECOND(”16:30:00.543876”);  | 
| 4 | 
 MINUTE() It returns the minutes of the time. Example − SELECT MINUTE(”2016-05-22 17:22:01”);  | 
| 5 | 
 SECOND() It returns the seconds of the date. Example − SELECT SECOND(”2016-03-12 16:30:04.000001”);  | 
| 6 | 
 TIME_FORMAT() It formats the time in accordance with the specified format string. Example − SELECT TIME_FORMAT(”22:02:20”, ”%H %k %h %I %l”);  | 
| 7 | 
 TIMESTAMP() It provides a timestamp for an activity in the format yyyy-mm-dd hh:mm:dd. Example − CREATE TABLE orders_ (ID INT, tmst TIMESTAMP);  | 
MariaDB Numeric Functions
Given below are some important numeric functions in MariaDB −
| Sr.No | Name & Description | 
|---|---|
| 1 | 
 TRUNCATE() It returns a truncated number to decimal place specification. Example − SELECT TRUNCATE(101.222, 1);  | 
| 2 | 
 COS() It returns the cosine of x radians. Example − SELECT COS(PI());  | 
| 3 | 
 CEILING() It returns the smallest integer not below x. Example − SELECT CEILING(2.11);  | 
| 4 | 
 DEGREES() It converts radians to degrees. Example − SELECT DEGREES(PI());  | 
| 5 | 
 DIV() It performs integer division. Example − SELECT 100 DIV 4;  | 
| 6 | 
 EXP() It returns e to the power of x. Example − SELECT EXP(2);  | 
| 7 | 
 FLOOR() It returns the largest integer not above x. Example − SELECT FLOOR(2.01);  | 
| 8 | 
 LN() It returns the natural logarithm of x. Example − SELECT LN(3);  | 
| 9 | 
 LOG() It returns the natural logarithm or the logarithm to a given base. Example − SELECT LOG(3);  | 
| 10 | 
 SQRT() It returns the square root. Example − SELECT SQRT(16);  | 
MariaDB String Functions
Important string functions are given below −
| Sr.No | Name & Description | 
|---|---|
| 1 | 
 INSTR() It returns the position of the first instance of a substring. Example − SELECT INSTR(”rambutan”, ”tan”);  | 
| 2 | 
 RIGHT() It returns the rightmost string characters. Example − SELECT RIGHT(”rambutan”, 3);  | 
| 3 | 
 LENGTH() It returns the byte length of a string. Example − SELECT LENGTH(”rambutan”);  | 
| 4 | 
 LOCATE() It returns the position of the first instance of a substring. Example − SELECT LOCATE(”tan”, ”rambutan”);  | 
| 5 | 
 INSERT() It returns a string, with a specified substring at a certain position, that was modified. Example − SELECT INSERT(”ramputan”, 4, 1, ”b”);  | 
| 6 | 
 LEFT() It returns the leftmost characters. Example − SELECT LEFT(”rambutan”, 3);  | 
| 7 | 
 UPPER() It changes characters to uppercase. Example − SELECT UPPER(lastname);  | 
| 8 | 
 LOWER() It changes characters to lowercase. Example − SELECT LOWER(lastname);  | 
| 9 | 
 STRCMP() It compares strings and returns 0 when they are equal. Example − SELECT STRCMP(”egg”, ”cheese”);  | 
| 10 | 
 REPLACE() It returns a string after replacing characters. Example − SELECT REPLACE(”sully”, ”l”, ”n”);  | 
| 11 | 
 REVERSE() It reverses characters in a string. Example − SELECT REVERSE(”racecar”);  | 
| 12 | 
 REPEAT() It returns a string repeating given characters x times. Example − SELECT REPEAT(”ha ”, 10);  | 
| 13 | 
 SUBSTRING() It returns a substring from a string, starting at position x. Example − SELECT SUBSTRING(”rambutan”,3);  | 
| 14 | 
 TRIM() It removes trailing/leading characters from a string. Example − SELECT TRIM(LEADING ”_” FROM ”_rambutan”);  | 
