Java Tutorial/Database/ResultSet Concurrency — различия между версиями
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Текущая версия на 08:06, 1 июня 2010
Get ResultSet Concurrency
<source lang="java">
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", ""); }
}</source>
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).