Do both. For a MySQL database, there exists phpMyAdmin which allows people to view the contents of their database, phpMyAdmin supports both, and both are great!
If I want to change a lot of info I click the edit and then get a complete form to edit the whole row.
If I want to change a single value, I double click and the cell changes into an input.
The fact that both of the options exist, saves me a noticable amount of time.
In terms of UX, I suggest you make something like a tooltip or a small legend as double click isn't very common in websites. But, uncommon != impossible, nor unpractical. I'm assuming lab people are somewhat similar to power users, and we love this kind of data editting.