In MySQL, the VAR_POP() function returns the population standard variance of an expression.
If there are no matching rows, or if the expression is NULL, VAR_POP() it returns NULL.
VAR_POP() is an aggregate function, and so it can be used with the GROUP BY clause.
The VAR_POP() function is standard SQL. There’s also a VARIANCE() function that does the same thing, but is not standard SQL.
In MySQL, the STDDEV_SAMP() function returns the sample standard deviation of a given expression. This is the square root of VAR_SAMP().
STDDEV_SAMP() is an aggregate function, and so it can be used with the GROUP BY clause.
If there are no matching rows, or if the expression is NULL, STDDEV_SAMP() returns NULL.
In MySQL, the STDDEV() function returns the population standard deviation of a given expression.
STDDEV() is a synonym for the standard SQL function STDDEV_POP(). There’s also a STD() function which also does the same thing, so we can use either of these functions to get the same result.
In MySQL, the STD() function returns the population standard deviation of a given expression.
STD() is a synonym for the standard SQL function STDDEV_POP(). There’s also a STDDEV() function which also does the same thing, so we can use either of these functions to get the same result.
In MySQL, the BIT_XOR() function returns the bitwise XOR of all bits in a given expression.
XOR is an exclusive OR, and so a XOR b is mathematically equal to (a AND (NOT b)) OR ((NOT a) and b).
In MySQL, the BIT_OR() function returns the bitwise OR of all bits in a given expression.
In MySQL, the BIT_AND() function returns the bitwise AND of all bits in a given expression.
In MySQL, the JSON_SCHEMA_VALIDATION_REPORT() function validates a JSON document against a JSON schema and returns a report of the outcome of that validation. The report is returned as a JSON document.
If the document is valid, only one field is returned: "valid" : true. If the document is not valid, a more extensive report is provided.
In MySQL, the JSON_SCHEMA_VALID() function validates a JSON document against a JSON schema. It returns true (1) if the document is valid, and false (0) if it is not.