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+# Built In Functions
+
+MySQL  provides numerous built-in functions that streamline data manipulation and retrieval directly within your SQL queries.
+
+Utilizing these functions minimizes application-level processing, leading to more robust and performant code. This guide covers essential MySQL functions, focusing on their practical utility for Java developers.
+
+## Numeric Functions
+
+Optimize calculations directly in the database layer.
+
+```sql
+-- Rounds 5.73 to the nearest whole number.
+SELECT ROUND(5.73);
+```
+Output: 6
+
+```sql
+-- Rounds 5.73 to one decimal place.
+SELECT ROUND(5.73, 1);
+```
+Output: 5.7
+
+```sql
+-- Truncates 5.758 2 to two decimal places without rounding.
+SELECT TRUNCATE(5.7582, 2);
+```
+Output: 5.75
+
+```sql
+-- Returns the smallest integer greater than or equal to 5.2 .
+SELECT CEILING(5.2);
+```
+Output: 6
+
+```sql
+-- Returns the largest integer less than or equal to 5.7.
+SELECT FLOOR(5.7);
+```
+Output : 5
+
+```sql
+-- Returns the absolute value of -5.2.
+SELECT ABS(-5.2);
+```
+Output: 5.2
+
+```sql
+-- Generates a random floating-point number  between 0 and 1. Useful for sampling or generating random data.
+SELECT RAND();
+```
+
+## String Functions
+
+Manipulate character data efficiently within queries.
+
+```sql
+-- Returns the length of the string 'sky'.
+SELECT  LENGTH('sky');
+```
+Output: 3
+
+```sql
+-- Converts the string 'sky' to uppercase.
+SELECT UPPER('sky');
+```
+Output: SKY
+
+```sql
+-- Converts the string 'sky'  to lowercase.
+SELECT LOWER('sky');
+```
+Output: sky
+
+```sql
+-- Removes leading spaces from '    sky'.
+SELECT LTRIM('    sky');
+```
+Output: sky
+
+```sql
+-- Removes  trailing spaces from 'sky    '.
+SELECT RTRIM('sky    ');
+```
+Output: sky
+
+```sql
+-- Removes leading and trailing spaces from '   sky  '.
+SELECT TRIM('   sky  ');
+``` Output: sky
+
+```sql
+-- Extracts the leftmost 4 characters from 'Kindergarten'.
+SELECT LEFT('Kindergarten', 4);
+```
+Output: Kind
+
+```sql
+-- Extracts the rightmost 6 characters from 'Kindergarten'.
+SELECT RIGHT('Kindergarten', 6);
+```
+Output: garten
+
+```sql
+-- Extracts 5 characters from 'Kindergarten' starting at position 3.
+SELECT SUBSTRING('Kindergarten', 3,  5);
+```
+Output: nderg
+
+```sql
+-- Returns the position of the first occurrence of 'n' in 'Kindergarten'. Returns 0 if not found.
+SELECT LOCATE('n','Kindergarten');
+```
+Output: 3
+
+```sql
+-- Replaces all occurrences of 'garten' with 'garden' in 'Kindergarten'.
+SELECT REPLACE('Kindergarten', 'garten', 'garden');
+```
+Output: Kindergarden
+
+```sql
+-- Concatenates 'first' and 'last'.
+SELECT CONCAT('first', 'last');
+```
+Output: firstlast
+
+## Date Functions
+
+Retrieve and extract components of date and time values.
+
+```sql
+--  Returns the current date and time (YYYY-MM-DD HH:MI:SS format). [1]
+SELECT NOW();
+```
+Example Output: 2025-06-19 16:31:0 0
+
+```sql
+-- Returns the current date (YYYY-MM-DD format). [1]
+SELECT CURDATE();
+```
+Example Output: 2025-06-19
+
+```sql
+-- Returns the current time ( HH:MI:SS format). [1]
+SELECT CURTIME();
+```
+Example Output: 16:31:00
+
+```sql
+-- Extracts the month as a number from a date/datetime. [1]
+SELECT MONTH(NOW());
+```
+Example Output: 6
+
+```sql
+-- Extracts the year as a number from a date/datetime. [1]
+SELECT YEAR(NOW());
+```
+Example Output: 20 25
+
+```sql
+-- Extracts the hour as a number from a time/datetime. [1]
+SELECT HOUR(NOW());
+```
+Example Output: 16
+
+## Formatting Dates and Times
+
+Customize date and time output strings  for application display.
+
+The default MySQL date format is "YYYY-MM-DD". Use `DATE_FORMAT()` and `TIME_FORMAT()` to control the output string representation.
+
+```sql
+-- Form ats the current date and time. [1, 4]
+SELECT DATE_FORMAT(NOW(), '%M %D %Y');
+```
+Example Output: June 19th 2025
+
+```sql
+-- Formats the current  date with numeric month and day. [1, 4]
+SELECT DATE_FORMAT(NOW(), '%m %d %y');
+```
+Example Output: 06 19 25
+
+```sql
+-- Formats  the current date with numeric month and day with English suffix. [1, 4]
+SELECT DATE_FORMAT(NOW(), '%m %D %y');
+```
+Example Output: 06 19th 2 5
+
+```sql
+-- Formats the current time. [1, 4]
+SELECT TIME_FORMAT(NOW(), '%H %i %p');
+```
+Example Output: 16 31 PM
+
+## Calculating  Dates and Times
+
+Perform date and time arithmetic directly in queries.
+
+```sql
+-- Adds 1 day to the current date and time. [1, 2]
+SELECT DATE_ADD(NOW(), INTERVAL 1 DAY);
+```
+Example Output: 2025-06-20 16:31:00
+
+```sql
+-- Subtracts 1 year from the current date and time. [1, 2]
+SELECT DATE_ADD(NOW(), INTERVAL -1 YEAR);
+```
+Example Output: 2024-06-19 16:31:00
+
+```sql
+-- Also subtracts 1 year from  the current date and time. [1, 2]
+SELECT DATE_SUB(NOW(), INTERVAL 1 YEAR);
+```
+Example Output: 2024-06-19 16:31 :00
+
+```sql
+-- Returns the difference in days between two dates. Time components are ignored for the difference calculation. [1, 7]
+SELECT DATEDIFF('2025-06-19  09:00', '2025-04-10 17:00');
+```
+Output: 70
+
+```sql
+-- Calculates the difference between two times in seconds by converting  them to seconds past midnight. [5, 7]
+SELECT TIME_TO_SEC('09:00') - TIME_TO_SEC('09:02');
+```
+Output: -120