I have been through an endless number of applications and I have never seen a set of icons that I really liked to represent data query, data definition and data manipulation in SQL. Finally, I decided to create a convention of my own.
I attempted to come up with a clearly distinct image for each operation. I also would like to apply these foundation icons consistently to create a complete set of DQL, DDL and DML icons. For example, below is the set of icons for operations on databases:
The same applied to tables:
And to columns of tables:
As you can see, the metaphor is consistent and communicative. I will be working on more icons for future posts.