PolarDB-X 1.0 supports a subset of the MySQL 5.7 aggregate functions. Check the tables below before writing your queries to confirm whether a function is available.
Supported functions
| Function | Description |
|---|---|
AVG() | Returns the average value of the argument |
COUNT() | Returns a count of the number of rows returned |
COUNT(DISTINCT) | Returns the count of a number of different values |
MAX() | Returns the maximum value |
MIN() | Returns the minimum value |
SUM() | Returns the sum |
Unsupported functions
The following MySQL 5.7 aggregate functions are not supported by PolarDB-X 1.0. If your queries rely on these functions, rewrite them using the supported functions above or handle the logic at the application layer.
| Function | Description |
|---|---|
BIT_AND() | Returns bitwise AND |
BIT_OR() | Returns bitwise OR |
BIT_XOR() | Returns bitwise XOR |
GROUP_CONCAT() | Returns a concatenated string |
STD() | Returns the population standard deviation |
STDDEV() | Returns the population standard deviation |
STDDEV_POP() | Returns the population standard deviation |
STDDEV_SAMP() | Returns the sample standard deviation |
VAR_POP() | Returns the population standard variance |
VAR_SAMP() | Returns the sample variance |
VARIANCE() | Returns the population standard variance |