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.
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.
Continue readingThere 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 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.
Continue readingIf 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.
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.
Continue readingIn 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.
Continue readingIn 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.
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.
Continue readingIn SQL Server, the CAST() function converts an expression of one data type to another.
Here’s a quick overview of the function with examples.
Continue reading