The error means that you have data in other tables that references the data you are trying to delete. You would need to either drop and recreate the constraints or delete the data that the Foreign Key references. Suppose you have the following tables dbo.Students ( StudentId StudentName StudentTypeId ) dbo.StudentTypes ( StudentTypeId StudentType ) … Read more
The closest you’ll get with the ORM is Book.objects.all().delete(). There are differences though: truncate will likely be faster, but the ORM will also chase down foreign key references and delete objects in other tables.
Try the following. It is pretty rudimentary. Just finds the first space starting at the desired length. public static string TruncateAtWord(this string value, int length) { if (value == null || value.Length < length || value.IndexOf(” “, length) == -1) return value; return value.Substring(0, value.IndexOf(” “, length)); }
TRUNCATE doesn’t generate any rollback data, which makes it lightning fast. It just deallocates the data pages used by the table. However, if you are in a transaction and want the ability to “undo” this delete, you need to use DELETE FROM, which gives the ability to rollback. EDIT: Note that the above is incorrect … Read more
In SQL Server, you can rollback a TRUNCATE from a transaction. It does write page deallocation to the log, as you mentioned.
This has come up a few times recently, both on SO and on the PostgreSQL mailing lists. The TL;DR for your last two points: (a) The bigger shared_buffers may be why TRUNCATE is slower on the CI server. Different fsync configuration or the use of rotational media instead of SSDs could also be at fault. … Read more
Take a look at String#truncate from or String#truncate_words from Rails, it partially does want you want. If you test whether it got truncated or not, you could add some of the last part back after the truncated part. ‘Once upon a time in a world far far away’.truncate(27) # => “Once upon a time in … Read more
It just is. I’ve never noticed a problem though because one of my checks would be to ensure my parameters match my table column lengths. In the client code too. Personally, I’d expect SQL to never see data that is too long. If I did see truncated data, it’d be bleeding obvious what caused it. … Read more
Just to add another answer, : > filename : is a no-op in bash (POSIX-compliant), so this essentially just opens the file for writing (which of course truncates the file) and then immediately closes it. EDIT: as shellter commented, you don’t actually need a command to go along with the redirection: $ echo foo > … Read more
function truncate(input) { if (input.length > 5) { return input.substring(0, 5) + ‘…’; } return input; }; or in ES6 const truncate = (input) => input.length > 5 ? `${input.substring(0, 5)}…` : input;