使用H2数据库在JDBC中从负-509变为正510

本文介绍了使用H2数据库在JDBC中从负-509变为正510的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我是通过使用JDBC，可以看到某种改变或错误的数据。所以我观察到在Java 8 Update 151上使用 H2数据库版本1.4.196。I am seeing some kind of altered or erroneous data, with the use of JDBC. So I observe using H2 Database version 1.4.196 on Java 8 Update 151.这是一个完整的例子。 Here is a complete example. 注意我们如何检索三次日期值，首先是 LocalDate 对象，其次是文本，第三作为从演员 LocalDate 对象中提取的 int 年份编号。在文本版本中，我们可以看到年份确实是负面的。神奇的是， LocalDate 有不同的年份数，而且它是正数而不是负数。好像是个bug。Note how we retrieve the date value three times, first as a LocalDate object, secondly as text, and thirdly as an int year number extracted from a cast LocalDate object. In the text version we can see that the year is indeed negative. Mysteriously the LocalDate has a different year number and it is positive rather than negative. Seems like a bug.private void doIt ( ){ System.out.println( "BASIL - Running doIt." ); try { Class.forName( "org.h2.Driver" ); } catch ( ClassNotFoundException e ) { e.printStackTrace( ); } try ( Connection conn = DriverManager.getConnection( "jdbc:h2:mem:" ) ; // Unnamed throw-away in-memory database. ) { conn.setAutoCommit( true ); String sqlCreate = "CREATE TABLE history ( id IDENTITY , when DATE ); "; String sqlInsert = "INSERT INTO history ( when ) VALUES ( ? ) ; "; String sqlQueryAll = "SELECT * FROM history ; "; PreparedStatement psCreate = conn.prepareStatement( sqlCreate ); psCreate.executeUpdate( ); PreparedStatement psInsert = conn.prepareStatement( sqlInsert ); psInsert.setObject( 1 , LocalDate.of( 2017 , 1 , 23 ) ); psInsert.executeUpdate( ); psInsert.setObject( 1 , LocalDate.of( -509 , 1 , 1 ) ); psInsert.executeUpdate( ); PreparedStatement psQueryAll = conn.prepareStatement( sqlQueryAll ); ResultSet rs = psQueryAll.executeQuery( ); while ( rs.next( ) ) { long l = rs.getLong( 1 ); // Identity column. // Retrieve the same date value in three different ways. LocalDate ld = rs.getObject( 2 , LocalDate.class ); // Extract a `LocalDate`, and implicitly call its `toString` method that uses standard ISO 8601 formatting. String s = rs.getString( 2 ); // Extract the date value as text from the database using the database-engine’s own formatting. int y = ( ( LocalDate ) rs.getObject( 2 , LocalDate.class ) ).getYear( ); // Extract the year number as an integer from a `LocalDate` object. String output = "ROW: " + l+ " | " + ld + " | when as String: " + s+ " | year: " + y ; System.out.println( output ); } conn.close( ); } catch ( SQLException e ) { e.printStackTrace( ); }}运行时。行：2 | 0510-01-01 |当作为字符串时：-509-01-01 |年：510 ROW: 2 | 0510-01-01 | when as String: -509-01-01 | year: 510因此，似乎有涉及JDBC的事情。请注意年份如何呈现为正510而不是负509.我不明白这种行为。 So there seems to be something going on with JDBC being involved. Note how the year is presented as a positive 510 rather than a negative 509. I do not understand this behavior. 我可以在中推断出这是一个问题。 JDBC 而不是 LOCALDATE 。请参阅在IdeOne.com上直播的示例代码，显示 LocalDate 对象确实携带并报告负面年份。 I can deduce that it is an issue within JDBC rather than within LocalDate. See this example code run live in IdeOne.com showing that a LocalDate object does indeed carry and report a negative year. LocalDate ld = LocalDate.of( -509 , 1 , 1 ) ;System.out.println( "ld.toString(): " + ld ) ;System.out.println( "ld.getYear(): " + ld.getYear() ) ;注意我们在交易时如何不从-509转换为510只有 LocalDate ，没有JDBC。Notice how we do not get converted from -509 to 510 when dealing with a LocalDate only, with no JDBC. ld.getYear（）： - 509 ld.getYear(): -509我打开了关于H2项目的发行票。 I opened a Issue ticket on the H2 project. 推荐答案 错误，已修复 此问题是由于 H2中的错误。 现已修复，截至2018-01。Now fixed, as of 2018-01. 这篇关于使用H2数据库在JDBC中从负-509变为正510的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！