我试图从h2db中获取值，但总是出现此错误org.h2.jdbc.JdbcSQLException:Nodataisavailable[2000-171]atorg.h2.message.DbException.getJdbcSQLException(DbException.java:329)atorg.h2.message.DbException.get(DbException.java:169)atorg.h2.message.DbException.get(DbException.java:146)atorg.h2.message.DbException.get(DbExcept