In Oracle, we can use the LISTAGG() function to convert our query results to a comma separated list.
So, instead of each value being output in a separate row, all values are output in a single row, separated by a comma (or some other delimiter of our choosing).
Continue readingIf you’re receiving error Msg 8115, Level 16, Arithmetic overflow error converting int to data type numeric in SQL Server, it’s probably because you’re performing an operation that results in a data conversion error due to an out of range value.
This will often happen when you try to convert a number to a different data type, but it’s out of the accepted range for the new data type.
Continue readingIf you’re receiving error Msg 8115, Level 16, Arithmetic overflow error converting expression to data type int in SQL Server, it could be that you’re performing a calculation that results in an out of range value.
This can happen when you use a function such as SUM() on a column, and the calculation results in a value that’s outside the range of the column’s type.
If you’re getting error “Msg 8115, Level 16 Arithmetic overflow error converting IDENTITY to data type…” error in SQL Server, it’s probably because you’re trying to insert data into a table when its IDENTITY column has reached its data type’s limit.
An IDENTITY column automatically increments the value that’s inserted with each new row. If the value being inserted is out of the range of the column’s data type, then the above error will occur.
GUIs like SSMS or Azure Data Studio make it easy to see a column’s data type. Usually it’s a simple matter of navigating to the column in the object explorer and you can see the data type right next to the column.
But if you’re using T-SQL, you’ll need to run a query.
Continue readingThere are several ways to format a number as a percentage in SQL, depending on the DBMS being used.
Here are examples of adding a percent sign to a number in some of the most popular DBMSs.
Continue readingIf you’re formatting a number in PostgreSQL, and you want to change the locale so that the correct group and decimal separators are used, here’s how you can do that.
Continue readingIn 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.
The very useful DROP TABLE IF EXISTS syntax was finally introduced in Oracle Database – Oracle Database 23c to be precise. This syntax allows us to run a DROP TABLE statement without getting an error if the table doesn’t exist.
Earlier versions of Oracle don’t support the IF EXISTS clause. Therefore, if we want to avoid any nasty errors resulting from trying to drop a non-existent table, we need to do a bit of extra work.
Below are three options for dropping a table if it exists in Oracle.
Continue readingIn 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.