Q:

Why does MySQL always return no data for this query?

I have a database in which a few fields are set as index. I don't know if this has to do with the problem or not, but when creating a query I get no results.  Here is how I have things set in the database. The database has 90,000 records and this table is set like:
| fieldA  | fieldB | fieldC  | fieldD |

fieldA = index - CHAR
fieldB = index - CHAR
fieldC = index - CHAR
fieldD = index - VARCHAR

If I do:
SELECT * 
  FROM tableA 
 WHERE 'fieldD'='A LONG STRING WITH SYMBOLS AND CHARCTERS';

I get 0 results and I know that the value for fieldD exist and is there.
What am I doing wrong? 

A:

It looks to me like your problem is you're enclosing your column names with single quotes.  This is causing MySQL to treat it as a string instead of a column name, so you are literally comparing the string 'fieldA' with long string.  Remove the quotes from around the column name and you should be good to go.
SELECT * FROM tableA WHERE fieldD='A LONG STRING WITH SYMBOLS AND CHARCTERS';

