In MariaDB, MAX() is an aggregate function that returns the maximum value in a given expression.
Tag: aggregate functions
PostgreSQL GROUP_CONCAT() Equivalent
Some RDBMSs like MySQL and MariaDB have a GROUP_CONCAT() function that allows you to return a query column as a delimited list (for example, a comma separated list).
PostgreSQL has a similar function called STRING_AGG(). This function works in pretty much the same way that GROUP_CONCAT() works in MySQL and MariaDB.
Oracle GROUP_CONCAT() Equivalent
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.
GROUP_CONCAT() Function in MySQL
MySQL has a GROUP_CONCAT() function that enables us to return columns from a query as a delimited list.
It returns a string result with the concatenated non-NULL values from a group.
LISTAGG() Function in Oracle
In Oracle, the LISTAGG() function enables us to combine data from multiple rows in to a single row.
We have the option of specifying a separator (such as a comma). We can also order the results produced by the LISTAGG() function, and more.
MariaDB GROUP_CONCAT()
MariaDB has a GROUP_CONCAT() function that enables us to return columns from a query as a delimited list.
STRING_AGG() Function in PostgreSQL
In PostgreSQL, we can use the STRING_AGG() function to return columns from a query as a delimited list.
SQL UNION Clause for Beginners
In SQL, the UNION clause concatenates the results of two queries into a single result set.
You can use the UNION clause with or without the ALL argument:
UNION ALL– Includes duplicates.UNION– Excludes duplicates.
Some RDBMSs also accept UNION DISTINCT, which is the equivalent to UNION. That is, it excludes duplicates.
Below are some basic examples to demonstrate how it works.
Continue readingSQL AVG() for Beginners
In SQL, the AVG() function is an aggregate function that returns the average of all values in a given expression.
It can also be used to return the average of all distinct (unique) values in an expression.
The expression must be numeric (it cannot be character string, bit string, or datetime).
Below are some basic examples to demonstrate how it works.
Continue readingSQL SUM() for Beginners
In SQL, the SUM() function is an aggregate function that returns the sum of all values in a given expression.
It can also be used to return the sum of all distinct (unique) values in an expression.
The expression must be numeric (it cannot be character string, bit string, or datetime).
Below are some basic examples to demonstrate how it works.
Continue reading