what is – Page 90

SUM() Function in MySQL

July 21, 2023December 10, 2021 by Ian

In MySQL, the SUM() aggregate function returns the sum of a given expression.

It can also be used to return the sum of all distinct (unique) values in an expression.

COUNT() Function in MariaDB

July 21, 2023December 5, 2021 by Ian

In MariaDB, the COUNT() aggregate function returns a count of the number of non-NULL values of an expression in the rows retrieved by a SELECT statement.

AVG() Function in MariaDB

July 21, 2023December 4, 2021 by Ian

In MariaDB, the AVG() function returns the average value of the given expression.

The DISTINCT option can be used to return the average of the distinct values (i.e. remove duplicates before calculating the average).

NULL values are ignored.

SUM() Function in MariaDB

July 21, 2023December 3, 2021 by Ian

In MariaDB, the SUM() aggregate function returns the sum of a given expression.

It can also be used to return the sum of all distinct (unique) values in an expression.

HAS_DBACCESS() – Discover if a User Can Access a Database in SQL Server

December 2, 2021 by Ian

SQL Server has a HAS_DBACCESS() function that returns information about whether the user has access to a specified database.

MIN() Function in MariaDB

July 21, 2023December 1, 2021 by Ian

In MariaDB, MIN() is an aggregate function that returns the minimum value in a given expression.

MAX() Function in MariaDB

July 21, 2023December 1, 2021 by Ian

In MariaDB, MAX() is an aggregate function that returns the maximum value in a given expression.

In SQL, LPAD()is a commonly used function that pads the left part of a string with a specified character. The function can be used on strings and numbers, although depending on the DBMS, numbers may have to be passed as a string before they can be padded.

DBMSs that have an LPAD() function include MySQL, MariaDB, PostgreSQL, and Oracle.

DBMSs that don’t have an LPAD() function include SQL Server and SQLite (although there are other ways to apply left padding in these DBMSs).

SQL RPAD()

November 28, 2021 by Ian

In SQL, RPAD()is used to pad the right part of a string with a specified character. The function can be used on strings and numbers, although depending on the DBMS, numbers may have to be passed as a string before they can be padded.

DBMSs that have an RPAD() function include MySQL, MariaDB, PostgreSQL, and Oracle.

DBMSs that don’t have an RPAD() function include SQL Server and SQLite.

Oracle GROUP_CONCAT() Equivalent

November 23, 2021 by Ian

Some RDBMSs have a GROUP_CONCAT() function that allows you to return a query column as a delimited list (for example, a comma separated list). MySQL and MariaDB are two that have such a function.

PostgreSQL and SQL Server have similar functions called STRING_AGG().

Oracle, on the other hand, has the LISTAGG() function that does pretty much the same thing (and perhaps more).

So you could say that LISTAGG() is Oracle’s GROUP_CONCAT() equivalent.