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.
Some DBMSs such as Oracle, MySQL, and MariaDB have a DESCRIBE command that returns information about tables and views. It goes DESCRIBE table where table is the name of the table or view, and it can also be followed by a column name if you only want information about a specific column.
PostgreSQL doesn’t have a DESCRIBE TABLE command as such, but there are alternatives.
MariaDB includes two built-in functions that allow us to get the ASCII code from a given character.
In SQLite, we can use the IF EXISTS clause of the DROP TABLE statement to check whether the table exists or not before dropping it.
There may be occasions where you need to check a column for non-numeric values. For example, you discover that a column is a varchar column when it really should be a numeric column.
This is easily done in SQL Server with the ISNUMERIC() function.
Here are three options for listing out all functions in a PostgreSQL database.
Here are some examples of formatting phone numbers in SQL Server.
This includes examples of formatting numbers in E.164 format (for international numbers), prepending the country code and area code, as well as omitting leading zero from the country code when required.
If you’re getting SQL Server error Msg 8116 with text that reads Argument data type date is invalid for argument 1 of substring function, it’s because you’re passing the wrong data type to a function – in this case, the SUBSTRING() function.
You could also see the same error (Msg 8116) in many other contexts – it’s not limited to the SUBSTRING() function.
MariaDB provides multiple ways of returning the data type of a column. Here are four ways to get the data type of a given column in MariaDB.
If you’re getting SQL Server error Msg 8114 that reads something like Error converting data type varchar to numeric, it’s probably because you’re trying to perform a data type conversion that fails due to the value not being able to be converted to the destination type.
It’s not because you can’t convert that type to the new type. It’s because of the value itself.