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| DataNucleus AccessPlatform 3.2 Documentation |
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JPQL provides an SQL-like query language. Just as with SQL, JPQL also supports a range of functions to enhance the querying possibilities.
There are a series of aggregate functions for aggregating the values of a field for all rows of the results.
| Function Name | Description | Standard |
|---|---|---|
| COUNT(field) | Returns the aggregate count of the field (Long) |  |
| MIN(field) | Returns the minimum value of the field (type of the field) | |
| MAX(field) | Returns the maximum value of the field (type of the field) | |
| AVG(field) | Returns the average value of the field (Double) | |
| SUM(field) | Returns the sum of the field value(s) (Long, Double, BigInteger, BigDecimal) | |
There are a series of functions to be applied to String fields.
| Function Name | Description | Standard |
|---|---|---|
| CONCAT(str_field, str_field2 [, str_fieldX]) | Returns the concatenation of the string fields | |
| SUBSTRING(str_field, num1 [, num2]) | Returns the substring of the string field starting at position num1, and optionally with the length of num2 | |
| TRIM([trim_spec] [trim_char] [FROM] str_field) | Returns trimmed form of the string field | |
| LOWER(str_field) | Returns the lower case form of the string field | |
| UPPER(str_field) | Returns the upper case form of the string field | |
| LENGTH(str_field) | Returns the size of the string field (number of characters) | |
| LOCATE(str_field1, str_field2 [, num]) | Returns position of str_field2 in str_field1 optionally starting at num | |
There are a series of functions for use with temporal values
| Function Name | Description | Standard |
|---|---|---|
| CURRENT_DATE | Returns the current date (day month year) of the datastore server | |
| CURRENT_TIME | Returns the current time (hour minute second) of the datastore server | |
| CURRENT_TIMESTAMP | Returns the current timestamp of the datastore server | |
| YEAR(dateField) | Returns the year of the specified date |  |
| MONTH(dateField) | Returns the month of the specified date | |
| DAY(dateField) | Returns the day of the month of the specified date | |
| HOUR(dateField) | Returns the hour of the specified date | |
| MINUTE(dateField) | Returns the minute of the specified date | |
| SECOND(dateField) | Returns the second of the specified date | |
There are a series of functions for use with collection values
| Function Name | Description | Standard |
|---|---|---|
| INDEX(field) | Returns index number of the field element when that is the element of an indexed List field. | |
| SIZE(collection_field) | Returns the size of the collection field. Empty collection will return 0 | |
There are a series of functions for arithmetic use
| Function Name | Description | Standard |
|---|---|---|
| ABS(numeric_field) | Returns the absolute value of the numeric field | |
| SQRT(numeric_field) | Returns the square root of the numeric field | |
| MOD(num_field1, num_field2) | Returns the modulus of the two numeric fields (num_field1 % num_field2 | |