Java Tutorial/Database/ResultSet Concurrency
Версия от 17:44, 31 мая 2010; (обсуждение)
Get ResultSet Concurrency
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Main {
public static void main(String[] args) throws Exception {
Connection conn = getConnection();
Statement st = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
st.executeUpdate("create table survey (id int,name varchar(30));");
st.executeUpdate("insert into survey (id,name ) values (1,"nameValue")");
st.executeUpdate("insert into survey (id,name ) values (2,null)");
st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM survey");
int rsConcurrency = rs.getConcurrency();
if (rsConcurrency == java.sql.ResultSet.CONCUR_READ_ONLY) {
System.out.println("java.sql.ResultSet.CONCUR_READ_ONLY");
} else if (rsConcurrency == java.sql.ResultSet.CONCUR_UPDATABLE) {
System.out.println("java.sql.ResultSet.CONCUR_UPDATABLE");
} else {
// it is an error
}
rs.close();
st.close();
conn.close();
}
private static Connection getConnection() throws Exception {
Class.forName("org.hsqldb.jdbcDriver");
String url = "jdbc:hsqldb:mem:data/tutorial";
return DriverManager.getConnection(url, "sa", "");
}
}
java.sql.ResultSet.CONCUR_READ_ONLY
ResultSet Concurrency
- Result sets have one of two concurrency types.
- A read-only result set is of type ResultSet.CONCUR_READ_ONLY,
- An updatable result set is of type ResultSet.CONCUR_UPDATABLE.
The java.sql.Connection interface has nine methods that set the result set concurrency. The default value (which is CONCUR_READ_ONLY).