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.
Here’s an example of using SQL to find duplicate rows in a database table. This technique can be used in most of the major RDBMSs, including SQL Server, Oracle, MySQL, MariaDB, PostgreSQL, and SQLite.
Continue readingHere are seven ways to return duplicate rows in PostgreSQL when those rows have a primary key or other unique identifier column.
This means that the duplicate rows share exactly the same values across all columns with the exception of their primary key/unique ID column.
Continue readingHere are eleven options for returning duplicate rows in Oracle Database when those rows have a primary key or some other unique identifier column and you want to ignore it.
Continue readingHere are eleven options for returning duplicate rows in SQLite when those rows have a primary key or some other unique identifier column (but you want to ignore the primary key).
This means that the duplicate rows share exactly the same values across all columns with the exception of their primary key/unique ID column.
Continue readingHere are five options for using SQL to return only those rows that have the minimum value within their group.
These examples work in most major RDBMSs, including MySQL, MariaDB, Oracle, PostgreSQL, SQLite, and SQL Server.
Continue readingThe following examples return duplicate rows from an Oracle Database table.
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