That's full of bad ideas, I'm afraid.
First off: Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.
When you concatenate strings, you cause problems because SQL receives commands like:
SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'
The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:
SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;
Which SQL sees as three separate commands:
SELECT * FROM MyTable WHERE StreetAddress = 'x';
A perfectly valid SELECT
DROP TABLE MyTable;
A perfectly valid "delete the table" command
And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.
So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?
Secondly, never hardcode connections strings - they should always be held in a config file of some form.
Thirdly, you shouldn't use
SELECT * FROM
, and you very particularly should never use
SELECT * FROM
and then access the resulting data via numeric indexes: if the database gets modified, your code breaks in nasty ways, which can end up corrupting your DB beyond repair.
And it's inefficient as well - never SELECT columns you don't intend to use!
SELECT Column1, Column2 FROM
and list the actual columns you are interested in - then access those via a numeric (or better text) index. It makes for more reliable software, as well as more readable and maintainable.
And most likely, that will fix your problem - I suspect that the column with index 3 you are returning is not the image data at all but an integer value...