SQL query in Java

[Eleeist]

Hi,

I have small problems with SQL queries in Java. I try to select all rows where the "category" column equals "helloworld". At first I tried like this:

SELECT * FROM commands WHERE category = helloworld

But I get error:

Unknown column 'helloworld' in 'where clause'

I also tried:

SELECT * FROM commands WHERE category LIKE helloworld

Same error message.

I am coming from PHP, where the first method, with "=" operator, works. Is it different in Java?

[PhQ]

try to put '`' when you are using a string in your WHERE thing.
Try this: SELECT * FROM `commands` WHERE category = `helloworld`

[Eleeist]

I changed it to:

SELECT * FROM `commands` WHERE `category` = `helloworld`

And still get the same error.

[doWhile]

Place quotes around the item you are selecting ( eg helloworld). That being said, I'd recommend using a PreparedStatement.

[Eleeist]

Thanks doWhile! I rewrote the code to use PreparedStatement and it started to work. Here is the new code:

public void getCommands(String category) throws Exception {
        
        Connection connection = connectToDatabase();
        
        PreparedStatement prest;
        String query = "SELECT * FROM commands WHERE category = ?";
        prest = connection.prepareStatement(query);
        prest.setString(1,"helloworld");
        
        ResultSet queryResult = prest.executeQuery();
        
        while (queryResult.next()) {
            
            String outputString = queryResult.getString("command");
            System.out.println(outputString);
        
        }
        
    }