从resultset读取空值

hgc7kmma  于 2021-06-30  发布在  Java
关注(0)|答案(2)|浏览(340)

下表可能包含sta、eta或ata的空值:

CREATE TABLE `flightschedule` (
  `id` smallint(6) NOT NULL AUTO_INCREMENT,
  `flightNum_arr` varchar(40) DEFAULT NULL,
  `from_ICAO` varchar(20) DEFAULT NULL,
  `STA` datetime DEFAULT NULL,
  `ETA` datetime DEFAULT NULL,
  `ATA` datetime DEFAULT NULL,
  `pk_arr` varchar(10) DEFAULT NULL
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=5611 DEFAULT CHARSET=latin1;

查询是:
从flightschedule中选择flightnum\u arr、sta、eta、ata、airlineicao、aircrafttype、pk\u arr”;
在java代码中尝试从该表读取数据时,会出现以下错误:
java.sql.sqlexception:无法将值“0000-00-00:00:00”从列2转换为时间戳。
它发生在第行 record[i] = rs.getString(i + 1); 我介绍了以下检查,但似乎不起作用:

if(record[i] == null)
{
   record[i]= "";
}

代码:

public void setQuery(String query) {
        cache = new Vector();
        try {
          // Execute the query and store the result set and its metadata
          Connection con = getConnection();
          Statement statement = con.createStatement();
          ResultSet rs = statement.executeQuery(query);
          ResultSetMetaData meta = rs.getMetaData();
          colCount = meta.getColumnCount();
          // Rebuild the headers array with the new column names
          headers = new String[colCount];
          for (int h = 1; h <= colCount; h++) {
            headers[h - 1] = meta.getColumnName(h);
          }
          while (rs.next()) {
            String[] record = new String[colCount];
            for (int i = 0; i < colCount; i++) {
              record[i] = rs.getString(i + 1);
              if(record[i] == null)
              {
                  record[i]= "";
              }
            }
            cache.addElement(record);
          }
          fireTableChanged(null);         
          rs.close();
          if (con.getAutoCommit() != false) {
            con.close();
          }         
        } catch (Exception e) {
          cache = new Vector(); // blank it out and keep going.
          e.printStackTrace();
        }
      }
u4vypkhs

u4vypkhs1#

对于datetimecolum,应该使用rs.gettimestamp()或rs.getdate(),而不是rs.getstring

omqzjyyz

omqzjyyz2#

我认为问题在于,您需要配置连接,以便根据以下帖子将零datetime转换为null:
在jdbc中处理datetime值0000-00-00:00:00

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