Is there a rails-way way to validate that an actual record is unique and not just a column? For example, a friendship model / table should not be able to have multiple identical records like: ...

...ner, it contains the data and log files, and all the schemas within it. You always back up a database, it is a discrete unit on its own. Schemas are like folders within a database, and are mainly used to group logical objects together, which leads to ease of setting permissions by schema. EDIT for ...

... bundle exec rake db:rollback rails destroy model <model_name> When you generate a model, it creates a database migration. If you run 'destroy' on that model, it will delete the migration file, but not the database ...

How can we check in a SQL Server WHERE condition whether the column is not null and not the empty string ( '' )? 7 Answe...

... From directory foo/, use git log -- A You need the '--' to separate <path>.. from the <since>..<until> refspecs. # Show changes for src/nvfs $ git log --oneline -- src/nvfs d6f6b3b Changes for Mac OS X 803fcc3 Initial Comm...

I have set Netbeans to show unchecked warnings in my Java code, but I am failing to understand the error on the following lines: ...

Could someone provide a description of what happens when an Activity calls its finish() method? 4 Answers ...

The intent is to have a product name appear in the tooltip of a thumbnail. Browsers do not create a tooltip from "ng-title" or "ng-attr-title." ...

... remote repository it does not show any remote branch by -a option. What could be the problem? How to debug it? In this snippet two of the remote branches are not shown: ...

It's not clear for me what is the difference in spring security between : 5 Answers 5...