从ResultSet中读取空值

时间:2013-06-06 10:38:45

标签: java sql datetime null resultset

下表中可能包含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:

  

SELECT flightNum_arr,STA,ETA,ATA,airlineICAO,aircraftType,pk_arr FROM   flightschedule“;

当我尝试从我的Java代码中读取此表中的数据时,会发生以下错误:

  

java.sql.SQLException:无法转换值'0000-00-00 00:00:00'   第2列到TIMESTAMP。

它出现在第record[i] = rs.getString(i + 1);

我介绍了以下检查,但它似乎不起作用:

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();
        }
      }

2 个答案:

答案 0 :(得分:1)

我认为问题在于您需要配置连接以根据以下帖子将零日期时间转换为空:

handling DATETIME values 0000-00-00 00:00:00 in JDBC

答案 1 :(得分:0)

对于DateTimeColum,您应该使用rs.getTimeStamp()或rs.getDate()而不是rs.getString