MySQL/Lua from string choosing

[kerovi]

Is there any way/function for finding a specific word from a string something like
If WorldDBQuery("Select `xyz` from `customtable` where `xyz` = '"abc"')
I'm asking if table `xyz` is like "Durotar, Barrens, Orgrimmar", how can I select only one word like Durotar and see if it exists since "Select `xyz` from `customtable` where `xyz` = '"abc"') selects whole string not specific word though. Thanks in advance.
Otherwise if you would suggest me easier way than sql tables (i want to make ban system for my global chat)