SQL Standard Functions¶

Category	Function	Description
Aggregation	`AVG()`	Calculates the average of a set of values.
	`COUNT()`	Counts the number of rows in a result set.
	`MAX()`	Returns the maximum value in a set of values.
	`MIN()`	Returns the minimum value in a set of values.
	`SUM()`	Sums up the values in a set of data.
Text	`CHAR_LENGTH()`	Returns the length of a string in characters.
	`LOWER()`	Converts a string to lowercase.
	`UPPER()`	Converts a string to uppercase.
	`SUBSTRING()`	Extracts a substring from a string.
	`TRIM()`	Removes leading and trailing spaces or specified characters from a string.
Mathematical	`ABS()`	Returns the absolute value of a number.
	`CEILING()`	Rounds a number up to the nearest integer.
	`FLOOR()`	Rounds a number down to the nearest integer.
	`MOD()`	Returns the remainder of a division operation.
Date and Time	`CURRENT_DATE`	Returns the current date.
	`CURRENT_TIME`	Returns the current time.
	`CURRENT_TIMESTAMP`	Returns the current date and time.
	`EXTRACT()`	Extracts a specific part of a date, such as year, month, day, etc.
Type Conversion	`CAST()`	Converts a value from one data type to another.
	`CONVERT()`	Similar to `CAST()`, converts a value from one data type to another, with variations by DBMS.
Flow Control	`CASE`	Conditional expression that returns a value based on different conditions.
	`COALESCE()`	Returns the first non-null value in a list of arguments.
Analytical	`ROW_NUMBER()`	Assigns a unique row number to each row in a result set, based on the specified order.
	`RANK()`	Assigns a rank to each row in a result set, with possible ties.
	`DENSE_RANK()`	Similar to `RANK()`, but without gaps in the rank for tied values.

Reference: List of SQL reserved words - Wikipedia