Aggregate Functions
Aggregate functions compute one value from the values of all of the documents in a group, as defined by a Group By clause. Without GROUP BY, all of the selected documents form a single group.
- Avg - Returns the average (arithmetic mean) of the values in each group.
- Count - Returns the number of values in each group. Count(0) and Count(*) count the documents in each group.
- CountDistinct - Returns the number of distinct values in each group. Values are compared without regard to case unless caseSensitive is true.
- GeometricMean - Returns the geometric mean of the values in each group: the nth root of their product. Useful for growth rates and ratios.
- Max - Returns the largest numeric value in each group. Use MaxString for text.
- MaxString - Returns the alphabetically largest value in each group.
- Mean - Returns the arithmetic mean of the values in each group (the same as Avg).
- Median - Returns the median (middle) value in each group. For an even number of values it is the average of the two middle values.
- Min - Returns the smallest numeric value in each group. Use MinString for text.
- MinString - Returns the alphabetically smallest value in each group.
- Mode - Returns the value that occurs most often in each group. When several values are tied, the first one encountered is returned.
- Sha1Agg - Returns a single SHA-1 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.
- Sha256Agg - Returns a single SHA-256 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.
- Sha512Agg - Returns a single SHA-512 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.
- Sum - Returns the total of the values in each group.
- Variance - Returns the population variance of the values in each group: how far the values are spread from their mean.
SQL :: MaxString
Returns the alphabetically largest value in each group.
SQL :: Mean
Returns the arithmetic mean of the values in each group (the same as Avg).
SQL :: Median
Returns the median (middle) value in each group. For an even number of values it is the average of the two middle values.
SQL :: Min
Returns the smallest numeric value in each group. Use MinString for text.
SQL :: MinString
Returns the alphabetically smallest value in each group.
SQL :: Mode
Returns the value that occurs most often in each group. When several values are tied, the first one encountered is returned.
SQL :: Order By
Order by sorts a result set by a given set of fields or expressions.
SQL :: Select
Select statements are used to read (or query) data from the database.
SQL :: Sha1Agg
Returns a single SHA-1 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.
SQL :: Sha256Agg
Returns a single SHA-256 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.