Urgent help Statement v/s PreparedStatement

Question

iam using Statement object but java specification says, PreparedStatement makes more efficient compared to Statement object can any body explain briefly about it.

Answer 1

i know that dynamically u can give values but specification says
PreparedStatements make the description calls at construction time,
Statements make them on every execution.what this means If you want to execute a sql statement multiple times, then a prepared statement is more efficient.
eg
Statement stmt = connection.createStatement();
stmt.execute("insert into users (username) values ('Tom')");
stmt.execute("insert into users (username) values ('Dick')");
stmt.execute("insert into users (username) values ('Harry')");vs
[code
String sql = "]insert into users (username) values (?);";
stmt = connection.prepareStatement(sql);
stmt.setString(1, "Tom");
stmt.execute();
stmt.setString(1, "Dick");
stmt.execute();
stmt.setString(1, "Harry");
stmt.execute();
With the first one, the database has to parse the query each time, check it for syntax errors, and then execute it.
Using a prepared statement, the parsing/error checking only happens once - when you prepare it. After that you can call the same statement with different values, and it will use that already "parsed and prepared" statement.
It already knows exactly the column types that will be returned from the query - that bit can't change. With a Statement, it has to work from scratch each time.
If you are executing the same piece of SQL hundreds/thousands of times, only changing the values, then Prepared statements come into their own.
Cheers,
evnafets