com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'bro' in 'where clause'

Question

I'm trying to query MySQL database

statement = conn.createStatement();
String sql = "select * from file_post where gas_key='"+commun+"'";
fp =statement.executeQuery(sql);

where commun is

String commun= (String) session.getAttribute("commun");

I'm getting exception:

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'bro' in 'where clause'

bro is the value of commun.

I also tried PreparedStatement, but that also gave me the same exception.

But when I make a query in MySQL command line:

select * from file_post where gas_key='bro';

It's perfect there and returns the exact data.

I can't figure out why it is giving me the exception when using the same query in a Java class.

Have you newly added this column in table. Commit it. It might be visible to SQL Developer of whatever IDE you are using in that particular session. — Amit Bhati, Aug 18 '15 at 13:52
Be careful: building queries this way makes you vulnerable to SQL injection ([read more](http://stackoverflow.com/q/601300/182402)). — Wander Nauta, Aug 18 '15 at 13:53
@WanderNauta sir, i m just a student n i m making this for a college project , so i m not so much concerned about security — user3443275, Aug 18 '15 at 13:56
@user3443275 And you're sure the person who is going to grade the project is as unconcerned? :) — Wander Nauta, Aug 18 '15 at 13:58

score 1 · Answer 1 · answered Aug 18 '15 at 13:53

1

This exception happens normally when you don't match the ", to avoid problems like this use a PreparedStatement

PreparedStatement st = con.prepareStatement("SELECT * FROM file_post WHERE gas_key=?");
st.setString(1,commun);
rs = st.executeQuery();

answered Aug 18 '15 at 13:53

Jordi Castilla

sir i changed that to LIKE but its still throwing the same exception – user3443275 Aug 18 '15 at 14:00
sir i tried that too (mentioned in the question) but that also gave me the same exception – user3443275 Aug 18 '15 at 14:05
if so, you must found the mapped domain columns were does not match database ones – Jordi Castilla Aug 18 '15 at 14:14
if all columns are maped and have the setters and getters, please show the mapping of your entities to check it – Jordi Castilla Aug 18 '15 at 14:24

score 0 · Answer 2 · answered Aug 19 '15 at 04:41

0

Can you try to print preparedStatement after setting variable...just to check what query is building...

System.out.println(preparedStatement);

and what is fp here? ResultSet?

answered Aug 19 '15 at 04:41

Mr. Noddy

yes sir fp is result set, n now the problem is solved , the problem was that the connections which i was getting from the connection pool was not working correctly, when i cleaned my project it started working – user3443275 Aug 19 '15 at 13:41
its good you found problem...and solved on your own...and dont call me sir please.....!! – Mr. Noddy Aug 20 '15 at 08:51

2 Answers2