I regularly need to pass variables into my queries, and when running multiple tests, it helps to have a way to change these variables easily, preferably, without having to go through the query each time and change the sql. Fortunately for me TOAD (Tool for Oracle Application Developers) for Oracle offers a way to do this with bound variables. Unfortunately, it does not seem to be enabled as a default setting, which means you have to set it yourself in the options. Frustratingly too, for some reason the setting seems to switch itself back off periodically too. Every time this happens, it confuses me briefly until it occurs to me to check, and every time I have to check I forget where in the options this feature lives, so here is how you change it.
In TOAD, select View>Options; in the pop-up that appears navigate to SQL Editor>General in the tree hierarchy; check the box "Scan statements for bound variables before execution" in the second set of options (as shown below).
To include a bound variable in a query simply precede it with an '&' e.g. '&date', and when you execute the query you will be prompted to enter the variable; in this case the date
Not difficult at all, but very, very useful.
James