How to use ampersand in JDBC? - oracle

Question

In oracle we using select * from table_name where column_name=&value in similar way how to use ampersand in JDBC?
stmt = conn.createStatement();
String sql;
sql="select emp_name from employees"+" where emp_no=?";
ResultSet rs=stmt.executeQuery(sql);
while(rs.next()){
String emp_name=rs.getString("emp_name");
System.out.println(emp_name);
}
i wrote the above code but it is not working(showing error)

Answer 1

Did you read the article I provided the link to?
You use the question mark ? to point out places in your query where you want to specify a parameter, and you have to use PreparedStatement. I can't test it, but it should be something like this:
// some code to obtain the Connection object
PreparedStatement stmt = null;
String yourQuery = " SELECT emp_name FROM employees WHERE emp_no = ? ";
try {
stmt = conn.prepareStatement(yourQuery);
stmt.setLong(1, 252);
ResultSet rs = stmt.executeQuery();
while(rs.next()) {
String emp_name = rs.getString("emp_name");
System.out.println(emp_name);
}
} finally {
// close the stmt etc.
}

Answer 2

I'd suggest using a PreparedStatement - from memory it's something like
Connection conn = getConnection();
PreparedStatement pstmnt = conn.prepareStatement("Select * from employees where emp_no =?");
pstmnt.setLong(1,emp_no);
ResultSet rs = pstmnt.executeQuery();
but the link that #Przemyslaw Kruglej high light above will almost certainly have a good example ( I haven;t read it though ... )