A question using the setString to pass parameter

Question

Hello, there:
part of my SQL statement is like this:
p_table.user_id in (?)
In my JDBC code, I wrote
String str = "usr1";
ps.setString(1, str)
to pass the parameter to the SQL statement - it works fine;
However, if I wrote (in order to select from multi-users)
String str=" 'usr1', 'usr2', 'usr3' ";
ps.setString(1, str);
the code will throw a SQLException; I heard the SQL statement will automatically add single quotes on both side so I changed to:
str = " usr1', 'usr2', 'usr3 ";
but it didn't work either, the same SQL Exception is thrown.
Do any people experience this and guide me what to do?
Thanks a lot,
Sway

Answer 1

I've never done that, but presumably the problem is that you're trying to use one string parameter to set multiple SQL strings.
You probably want where... in (?, ?, ?) and then call setString 3 times.
If the number of parameters is not fixed at compile time, you could build the "?, ?, ?" part of the query one "?" at a time in a loop, and likewise call setString N times in a loop. There may be a cleaner, more direct way to do this, but if there is, I don't know anything about it. Dig around the java.sql javadocs a little.