In MySQL, the SCHEMA() function is a synonym for the DATABASE() function. It 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.
2 Ways to Find Out Which Quarter a Date Belongs to in MariaDB
If you ever need to find out which quarter a date belongs to in MariaDB, here are two functions that will allow you to do just that.
Fix Msg 8117 “Operand data type varchar is invalid for sum operator” in SQL Server
If you’re getting SQL Server error Msg 8117 with the message Operand data type varchar is invalid for sum operator, it’s because you’re passing the wrong data type to an operator or function.
In this case, the error indicates that we’re passing a string to the SUM() function. The SUM() function does not operate on strings. It only works on numeric types.
The same error (Msg 8117) can also occur in other contexts – it’s not limited to the SUM() function.
How to Detect if a Value Contains at Least One Number in SQL Server
Sometimes you might need to search a database table for only those rows that contain at least one number in a given column.
Strictly speaking, numbers can be represented by words and other symbols, but for the purpose of this article, “number” means “numerical digit”.
Below is an example of how to use T-SQL to find rows that contain at least one number in SQL Server.
SUM() Function in PostgreSQL
In PostgreSQL, the SUM() function computes the sum of the non-null input values and returns the result.
In other words, it adds numbers and returns the result.
How to Get the Century from a Date in Oracle
With Oracle Database, we can use the TO_CHAR(datetime) function to return the century from a datetime value.
To do this, we can use either the CC format element, or the SCC format element. We can combine these with other format elements to do things like, display the ordinal number, spell out the century, etc.
2 Ways to Get the Character Sets Available in MariaDB
If you need to find the character sets that are available in your MariaDB installation, check out the following two methods.
Check if a Table Exists in Oracle
In Oracle Database, there are a number of views that we can query to find out whether a table exists.
AVG() Function in PostgreSQL
In PostgreSQL, the AVG() function computes the average (arithmetic mean) of all the non-null input values, and returns the result.
How to Find Non-Numeric Values in a Column in MySQL
In MySQL, you can run a query like the following to return non-numeric data from the column.
This can be helpful if you ever find a column that contains numeric data, but it was set up as a varchar or char column. You can use this query to find any non-numeric values that might have been inserted into the column. You can then deal with it any way you like, such as convert them to numeric, then change the column type.