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”); |