These are the docs for the Metabase master branch. Some features documented here may not yet be available in the latest release. Check out the docs for the latest version, Metabase v0.49.

List of expressions

For an introduction to expressions, check out the overview of custom expressions.

Aggregations

Aggregation expressions take into account all values in a field. They can only be used in the Summarize section of the query builder.

Average

Returns the average of the values in the column.

Syntax: Average(column)

Example: Average([Quantity]) would return the mean for the Quantity field.

Count

Returns the count of rows (also known as records) in the selected data.

Syntax: Count

Example: Count If a table or result returns 10 rows, Count will return 10.

CountIf

Only counts rows where the condition is true.

Syntax: CountIf(condition).

Example: CountIf([Subtotal] > 100) would return the number of rows where the subtotal were greater than 100.

CumulativeCount

The additive total of rows across a breakout.

Syntax: CumulativeCount.

Example: CumulativeCount.

CumulativeSum

The rolling sum of a column across a breakout.

Syntax: CumulativeSum(column).

Example: CumulativeSum([Subtotal]).

Related: Sum and SumIf.

Distinct

The number of distinct values in this column.

Syntax: Distinct(column).

Distinct([Last Name]). Returns the count of unique last names in the column. Duplicates (of the last name “Smith” for example) are not counted.

Max

Returns the largest value found in the column.

Syntax: Max(column).

Example: Max([Age]) would return the oldest age found across all values in the Age column.

Related: Min, Average, Median.

Median

Returns the median value of the specified column.

Syntax: Median(column).

Example: Median([Age]) would find the midpoint age where half of the ages are older, and half of the ages are younger.

Databases that don’t support median: SQLite, Vertica, SQL server, MySQL. Presto only provides approximate results.

Related: Min, Max, Average.

Min

Returns the smallest value found in the column.

Syntax: Min(column).

Example: Min([Salary]) would find the lowest salary among all salaries in the Salary column.

Related: Max, Median, Average.

Percentile

Returns the value of the column at the percentile value.

Syntax: Percentile(column, percentile-value)

Example: Percentile([Score], 0.9) would return the value at the 90th percentile for all values in that column.

Databases that don’t support percentile: H2, MySQL, SQL Server, SQLite, Vertica. Presto only provides approximate results.

Share

Returns the percent of rows in the data that match the condition, as a decimal.

Syntax: Share(condition)

Example: Share([Color] = "Blue") would return the number of rows with the Color field set to Blue, divided by the total number of rows.

StandardDeviation

Calculates the standard deviation of the column, which is a measure of the variation in a set of values. Low standard deviation indicates values cluster around the mean, whereas a high standard deviation means the values are spread out over a wide range.

Syntax: StandardDeviation(column)

Example: StandardDeviation([Population]) would return the SD for the values in the Population column.

Sum

Adds up all the values of the column.

Syntax: Sum(column)

Example: Sum([Subtotal]) would add up all the values in the Subtotal column.

SumIf

Sums up the specified column only for rows where the condition is true.

Syntax: SumIf(column, condition).

Example:SumIf([Subtotal], [Order Status] = "Valid") would add up all the subtotals for orders with a status of “Valid”.

Variance

Returns the numeric variance for a given column.

Syntax: Variance(column)

Example: Variance([Temperature]) will return a measure of the dispersion from the mean temperature for all temps in that column.

Related: StandardDeviation, Average.

Functions

Function expressions apply to each individual value. They can be used to alter or filter values in a column, or create new, custom columns.

Logical functions

Logical functions determine if a condition is satisfied or determine what value to return based on a condition.

between

Checks a date or number column’s values to see if they’re within the specified range.

Syntax: between(column, start, end)

Example: between([Created At], "2019-01-01", "2020-12-31") would return rows where Created At date fell within the range of January 1, 2019 and December 31, 2020.

Related: interval.

case

Tests an expression against a list of cases and returns the corresponding value of the first matching case, with an optional default value if nothing else is met.

Syntax: case(condition, output, …)

Example: case([Weight] > 200, "Large", [Weight] > 150, "Medium", "Small") If a Weight is 250, the expression would return “Large”. In this case, the default value is “Small”, so any Weight 150 or less would return “Small”.

coalesce

Looks at the values in each argument in order and returns the first non-null value for each row.

Syntax: coalesce(value1, value2, …)

Example: coalesce([Comments], [Notes], "No comments"). If both the Comments and Notes columns are null for that row, the expression will return the string “No comments”.

isnull

Returns true if the column is null.

Syntax: isnull(column)

Example: isnull([Tax]) would return true if no value were present in the column for that row.

Related: notnull, isempty

notnull

Returns true if the column contains a value.

Syntax: notnull(column)

Example: notnull([Tax]) would return true if there is a value present in the column for that row.

Related: isnull, notempty

Math functions

Math functions implement common mathematical operations.

abs

Returns the absolute (positive) value of the specified column.

Syntax: abs(column)

Example: abs([Debt]). If Debt were -100, abs(-100) would return 100.

ceil

Rounds a decimal up (ceil as in ceiling).

Syntax: ceil(column).

Example: ceil([Price]). ceil(2.99) would return 3.

Related: floor, round.

exp

Returns Euler’s number, e, raised to the power of the supplied number. (Euler sounds like “Oy-ler”).

Syntax: exp(column).

Example: exp([Interest Months])

Related: power.

floor

Rounds a decimal number down.

Syntax: floor(column)

Example: floor([Price]). If the Price were 1.99, the expression would return 1.

Related: ceil, round.

log

Returns the base 10 log of the number.

Syntax: log(column).

Example: log([Value]).

power

Raises a number to the power of the exponent value.

Syntax: power(column, exponent).

Example: power([Length], 2). If the length were 3, the expression would return 9 (3 to the second power is 3*3).

Databases that don’t support power: SQLite.

Related: exp.

round

Rounds a decimal number either up or down to the nearest integer value.

Syntax: round(column).

Example: round([Temperature]). If the temp were 13.5 degrees centigrade, the expression would return 14.

Example: round([Temperature] * 10) / 10. If the temp were 100.75, the expression would return 100.8.

sqrt

Returns the square root of a value.

Syntax: sqrt(column).

Example: sqrt([Hypotenuse]).

Databases that don’t support sqrt: SQLite.

Related: Power.

String functions

String functions manipulate or validate string data.

concat

Combine two or more strings together.

Syntax: concat(value1, value2, …)

Example: concat([Last Name], ", ", [First Name]) would produce a string of the format “Last Name, First Name”, like “Palazzo, Enrico”.

contains

Checks to see if string1 contains string2 within it.

Performs case-sensitive match by default. You can pass an optional parameter "case-insensitive" to perform a case-insensitive match.

Syntax: contains(string1, string2) for case-sensitive match.

contains(string1, string2, "case-insensitive") for case-insensitive match.

Example: contains([Status], "Class").

If Status were “Classified”, the expression would return true. If the Status were “classified”, the expression would return false, because the case does not match.

Related: doesNotContain, regexextract.

doesNotContain

Checks to see if string1 contains string2 within it.

Performs case-sensitive match by default. You can pass an optional parameter "case-insensitive" to perform a case-insensitive match.

Syntax: doesNotContain(string1, string2) for case-sensitive match.

doesNotContain(string1, string2, "case-insensitive") for case-insensitive match.

Example: doesNotContain([Status], "Class"). If Status were “Classified”, the expression would return false.

Related: contains, regexextract.

endsWith

Returns true if the end of the text matches the comparison text.

Performs case-sensitive match by default. You can pass an optional parameter "case-insensitive" to perform a case-insensitive match.

Syntax: endsWith(text, comparison) for case-sensitive match.

endsWith(text, comparison, "case-insensitive") for case-insensitive match.

Example: endsWith([Appetite], "hungry")

Related: startsWith, contains, doesNotContain.

isempty

Returns true if a string column contains an empty string or is null. Calling this function on a non-string column will cause an error. You can use isnull for non-string columns.

Syntax: isempty(column)

Example: isempty([Feedback]) would return true if Feedback was an empty string ('') or did not contain a value.

Related: notempty, isnull

ltrim

Removes leading whitespace from a string of text.

Syntax: ltrim(text)

Example: ltrim([Comment]). If the comment were " I'd prefer not to", ltrim would return "I'd prefer not to".

Related: trim and rtrim.

length

Returns the number of characters in text.

Syntax: length(text)

Example: length([Comment]). If the comment were “wizard”, length would return 6 (“wizard” has six characters).

lower

Returns the string of text in all lower case.

Syntax: lower(text).

Example: lower([Status]). If the Status were “QUIET”, the expression would return “quiet”.

Related: upper.

notempty

Returns true if a string column contains a value that is not the empty string. Calling this function on a non-string column will cause an error. You can use notnull on non-string columns.

Syntax: notempty(column)

Example: notempty([Feedback]) would return true if Feedback contains a value that isn’t the empty string ('').

Related: isempty, isnull, notnull

regexextract

Extracts matching substrings according to a regular expression.

Syntax: regexextract(text, regular_expression).

Example: regexextract([Address], "[0-9]+").

Databases that don’t support regexextract: H2, SQL Server, SQLite.

Related: contains, doesNotContain, substring.

replace

Replaces all occurrences of a search text in the input text with the replacement text.

Syntax: replace(text, find, replace).

Example: replace([Title], "Enormous", "Gigantic").

rtrim

Removes trailing whitespace from a string of text.

Syntax: rtrim(text)

Example: rtrim([Comment]). If the comment were “Fear is the mindkiller. “, the expression would return “Fear is the mindkiller.”

Related: trim and ltrim.

startsWith

Returns true if the beginning of the text matches the comparison text. Performs case-sensitive match by default. You can pass an optional parameter "case-insensitive" to perform a case-insensitive match.

Syntax: startsWith(text, comparison) for case-sensitive match.

startsWith(text, comparison, "case-insensitive") for case-insensitive match.

Example: startsWith([Course Name], "Computer Science") would return true for course names that began with “Computer Science”, like “Computer Science 101: An introduction”.

It would return false for “Computer science 201: Data structures” because the case of “science” does not match the case in the comparison text.

startsWith([Course Name], "Computer Science", "case-insensitive") would return true for both “Computer Science 101: An introduction” and “Computer science 201: Data structures”.

Related: endsWith, contains, doesNotContain.

substring

Returns a portion of the supplied text, specified by a starting position and a length.

Syntax: substring(text, position, length)

Example: substring([Title], 1, 10) returns the first 10 letters of a string (the string index starts at position 1).

Related: regexextract, replace.

trim

Removes leading and trailing whitespace from a string of text.

Syntax: trim(text)

Example: trim([Comment]) will remove any whitespace characters on either side of a comment.

upper

Returns the text in all upper case.

Syntax: upper(text).

Example: upper([Status]). If status were “hyper”, upper("hyper") would return “HYPER”.

Date functions

Date functions manipulate, extract, or create date and time values.

convertTimezone

Shifts a date or timestamp value into a specified time zone.

Syntax: convertTimezone(column, target, source).

Example: convertTimezone("2022-12-28T12:00:00", "Canada/Pacific", "Canada/Eastern") would return the value 2022-12-28T09:00:00, displayed as December 28, 2022, 9:00 AM.

See the database limitations for convertTimezone.

datetimeAdd

Adds some unit of time to a date or timestamp value.

Syntax: datetimeAdd(column, amount, unit).

Example: datetimeAdd("2021-03-25", 1, "month") would return the value 2021-04-25, displayed as April 25, 2021.

Related: between, datetimeSubtract.

datetimeDiff

Returns the difference between two datetimes in some unit of time. For example, datetimeDiff(d1, d2, "day") will return the number of days between d1 and d2.

Syntax: datetimeDiff(datetime1, datetime2, unit).

Example: datetimeDiff("2022-02-01", "2022-03-01", "month") would return 1.

datetimeSubtract

Subtracts some unit of time from a date or timestamp value.

Syntax: datetimeSubtract(column, amount, unit).

Example: datetimeSubtract("2021-03-25", 1, "month") would return the value 2021-02-25, displayed as February 25, 2021.

Related: between, datetimeAdd.

day

Takes a datetime and returns the day of the month as an integer.

Syntax: day([datetime column]).

Example: day("2021-03-25T12:52:37") would return the day as an integer, 25.

hour

Takes a datetime and returns the hour as an integer (0-23).

Syntax: hour([datetime column]).

Example: hour("2021-03-25T12:52:37") would return 12.

interval

Checks a date column’s values to see if they’re within the relative range.

Syntax: interval(column, number, text).

Example: interval([Created At], -1, "month").

Related: between.

minute

Takes a datetime and returns the minute as an integer (0-59).

Syntax: minute([datetime column]).

Example: minute("2021-03-25T12:52:37") would return 52.

month

Takes a datetime and returns the month number (1-12) as an integer.

Syntax: month([datetime column]).

Example: month("2021-03-25T12:52:37") would return the month as an integer, 3.

now

Returns the current date and time using your Metabase report timezone.

Syntax: now.

quarter

Takes a datetime and returns the number of the quarter in a year (1-4) as an integer.

Syntax: quarter([datetime column]).

Example: quarter("2021-03-25T12:52:37") would return 1 for the first quarter.

relativeDateTime

Gets a timestamp relative to the current time.

Syntax: relativeDateTime(number, text)

number: Period of interval, where negative values are back in time.

text: Type of interval like "day", "month", "year"

relativeDateTime can only be used as part of a conditional expression.

Example: [Orders → Created At] < relativeDateTime(-30, "day") will filter for orders created over 30 days ago from current date.

Related: datetimeAdd, datetimeSubtract.

second

Takes a datetime and returns the number of seconds in the minute (0-59) as an integer.

Syntax: second([datetime column]).

Example: second("2021-03-25T12:52:37") would return the integer 37.

timeSpan

Gets a time interval of specified length.

Syntax: timeSpan(number, text).

number: Period of interval, where negative values are back in time.

text: Type of interval like "day", "month", "year"

Example: [Orders → Created At] + timeSpan(7, "day") will return the date 7 days after the Created At date.

week

Takes a datetime and returns the week as an integer.

Syntax: week(column, mode).

Example: week("2021-03-25T12:52:37") would return the week as an integer, 12.

  • column: the name of the column of the date or datetime value.
  • mode: Optional.
    • ISO: (default) Week 1 starts on the Monday before the first Thursday of January.
    • US: Week 1 starts on Jan 1. All other weeks start on Sunday.
    • Instance: Week 1 starts on Jan 1. All other weeks start on the day defined in your Metabase localization settings.

weekday

Takes a datetime and returns an integer (1-7) with the number of the day of the week.

Syntax: weekday(column)

  • column: The datetime column.

Example:

case(
  weekday([Created At]) = 1, "Sunday",
  weekday([Created At]) = 2, "Monday",
  weekday([Created At]) = 3, "Tuesday",
  weekday([Created At]) = 4, "Wednesday",
  weekday([Created At]) = 5, "Thursday",
  weekday([Created At]) = 6, "Friday",
  weekday([Created At]) = 7, "Saturday")

year

Takes a datetime and returns the year as an integer.

Syntax: year([datetime column]).

Example: year("2021-03-25T12:52:37") would return the year 2021 as an integer, 2,021.

Window functions

Offset

Returns the value of an expression in a different row. Offset can only be used in the query builder’s Summarize step (you cannot use Offset to create a custom column).

Syntax: Offset(expression, rowOffset)

The expression is the value to get from a different row.

The rowOffset is the number relative to the current row. For example, -1 for the previous row, or 1 for the next row.

Example: Offset(Sum([Total]), -1) would get the Sum([Total]) value from the previous row.

See Offset.

Limitations

  • Aggregation expressions can only be used in the Summarize section of the query builder.
  • Functions that return a boolean value, like isempty or contains, cannot be used to create a custom column. To create a custom column based on one of these functions, you must combine them with another function, like case.

For example, to create a new custom column that contains true if [Title] contain 'Wallet', you can use the custom expression

case(contains([Title], 'Wallet'), true, false)

Database limitations

Limitations are noted for each aggregation and function above, and here there are in summary:

H2 (including Metabase Sample Database): Median, Percentile, convertTimezone and regexextract

MySQL/MariaDB: Median, Percentile.

SQL Server: Median, Percentile and regexextract

SQLite: log, Median, Percentile, power, regexextract, StandardDeviation, sqrt and Variance

Vertica: Median and Percentile

Additionally, Presto only provides approximate results for Median and Percentile.

If you’re using or maintaining a third-party database driver, please refer to the wiki to see how your driver might be impacted.

Check out our tutorial on custom expressions in the query builder to learn more.

Read docs for other versions of Metabase.

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