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SQLSimplified

SQL Functions

A reference for the SQL functions you use every day, with interactive examples.

Numeric

ABS()
Numeric
Returns the absolute (non-negative) value of a number.
CEIL()
Numeric
Rounds a number up to the nearest integer (ceiling).
FLOOR()
Numeric
Rounds a number down to the nearest integer (floor).
GREATEST()
Numeric
Returns the largest value from a list of expressions.
LEAST()
Numeric
Returns the smallest value from a list of expressions.
MOD()
Numeric
Returns the remainder of a division (modulo).
POWER()
Numeric
Raises a base to a specified exponent.
ROUND()
Numeric
Rounds a numeric value to a specified number of decimal places.
SIGN()
Numeric
Returns -1, 0, or 1 indicating the sign of a number.
SQRT()
Numeric
Returns the square root of a non-negative number.
TRUNC()
Numeric
Truncates a number toward zero, removing digits past a given precision.

Aggregate

ARRAY_AGG()
Aggregate
Collects values from a group into a single array (list).
AVG()
Aggregate
Calculates the average (mean) of the values in a numeric column across a group of rows.
BOOL_AND()
Aggregate
Returns TRUE if every value in the group is TRUE (logical AND across rows).
BOOL_OR()
Aggregate
Returns TRUE if at least one value in the group is TRUE (logical OR across rows).
COUNT()
Aggregate
Returns the number of rows that match a query, optionally counting only non-null values in a specific column.
MAX()
Aggregate
Returns the largest value in a column across a group of rows.
MIN()
Aggregate
Returns the smallest value in a column across a group of rows.
STDDEV()
Aggregate
Returns the standard deviation of a set of values, measuring spread around the mean.
STRING_AGG()
Aggregate
Concatenates values from a group into a single string, separated by a delimiter.
SUM()
Aggregate
Adds up all the values in a numeric column across a group of rows.
VARIANCE()
Aggregate
Returns the variance (squared spread) of a set of numeric values.

Conversion

CAST()
Conversion
Converts a value from one data type to another, such as a number to text or text to a number.
COALESCE()
Conversion
Returns the first non-null value from a list of expressions.
NULLIF()
Conversion
Returns NULL if two expressions are equal; otherwise returns the first.
TO_CHAR()
Conversion
Formats a date, number, or timestamp as a string using a format pattern.
TO_DATE()
Conversion
Parses a string into a DATE using a format pattern.

String

CONCAT()
String
Joins two or more strings together into a single string.
LEFT()
String
Returns the first N characters from the left of a string.
LENGTH()
String
Returns the number of characters in a string.
LOWER()
String
Converts all characters in a string to lowercase.
LTRIM()
String
Removes leading (left-side) characters, usually spaces, from a string.
POSITION()
String
Returns the 1-based location of a substring within a string.
REPEAT()
String
Concatenates a string to itself a given number of times.
REPLACE()
String
Replaces all occurrences of a substring within a string.
REVERSE()
String
Returns the characters of a string in reverse order.
RIGHT()
String
Returns the last N characters from the right of a string.
RTRIM()
String
Removes trailing (right-side) characters, usually spaces, from a string.
SPLIT_PART()
String
Splits a string on a delimiter and returns the Nth piece.
SUBSTRING()
String
Extracts a portion of a string, starting at a given position and running for a given length.
TRIM()
String
Removes leading and/or trailing characters (usually spaces) from a string.
UPPER()
String
Converts all characters in a string to uppercase.

Date & Time

CURRENT_DATE()
Date and Time
Returns today's date (no time component).
CURRENT_TIMESTAMP()
Date and Time
Returns the current date and time (with time zone in some engines).
DATE_ADD()
Date and Time
Adds an interval to a date or timestamp.
DATE_SUB()
Date and Time
Subtracts an interval from a date or timestamp.
DATE_TRUNC()
Date and Time
Truncates a date/timestamp down to the start of a given unit.
DATEDIFF()
Date and Time
Returns the difference between two dates in a specified unit.
EXTRACT()
Date and Time
Pulls a single date part (year, month, day, ...) out of a date or timestamp.
NOW()
Date and Time
Returns the current date and time.