In SQL Server, 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 the expression.
SUM() only works on numeric columns. Null values are ignored.
functions
How TRY_CAST() Works in SQL Server
In SQL Server, an often used function is CAST(), which converts an expression of one data type to another. But if the cast doesn’t succeed, then it returns an error.
Enter TRY_CAST().
The TRY_CAST() function doesn’t return an error if the cast fails. Instead, it returns NULL.
There are some occasions however, where it will return an error.
How TRY_CONVERT() Works in SQL Server
In SQL Server, the TRY_CONVERT() function is very similar to the CONVERT() function, except that TRY_CONVERT() doesn’t return an error if the conversion fails (CONVERT() does).
Instead, the TRY_CONVERT() function returns NULL if the conversion doesn’t succeed.
There are some occasions however, where TRY_CONVERT() will return an error.
CONVERT() in SQL Server
In SQL Server, the CONVERT() function converts an expression of one data type to another.
Here’s a quick overview of the function with examples.
How CAST() Works in SQL Server
In SQL Server, the CAST() function converts an expression of one data type to another.
Here’s a quick overview of the function with examples.
MAX() Function in PostgreSQL
In PostgreSQL, the MAX() function computes the maximum of the non-null input values and returns the result.
This function can be used on any numeric, string, date/time, or enum type, as well as inet, interval, money, oid, pg_lsn, tid, and arrays of any of these types.
MIN() Function in PostgreSQL
In PostgreSQL, the MIN() function computes the minimum of the non-null input values and returns the result.
This function can be used on any numeric, string, date/time, or enum type, as well as inet, interval, money, oid, pg_lsn, tid, and arrays of any of these types.
DATABASE() – Get the Current Database Name in MySQL
In MySQL, DATABASE() is a built-in function that returns the default (current) database name.
The result is returned as a string in the utf8 character set. If there is no default database, it returns NULL.
SUM() Function in MySQL
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.