Question

我正在从.csv文件导入数据库值。但是，.csv中的最后一行实际上是某些列的总和，而我的导入器使用最后一行更新数据库，这是不合需要的。这会弄乱我稍后会用它做的查询。请帮助我如何防止这种情况？

我的.csv导入程序的代码：

try
{
    BufferedReader br=new BufferedReader(new FileReader("v.csv"));
    String line;
    while((line=br.readLine())!=null)
    {
        String[]value = line.split(",");
        String sql = "INSERT into main ([Ticket #], Status, Priority, Department, [Account Name]) "
                + "values ('"+value[0]+"','"+value[1]+"','"+value[2]+"','"+value[3]+"','"+value[4]+"')";
        System.out.println(sql);
        PreparedStatement pst = null;
        try
        {
            pst = db.prepareStatement(sql);
            pst.executeUpdate();
        }finally{
            if(pst != null){
                pst.close();
            }
        }
    }
    br.close();
}
catch(Exception e)
{
    JOptionPane.showMessageDialog(null, e);
}

Answer 1

试试这个：

try
{
    BufferedReader br=new BufferedReader(new FileReader("v.csv"));
    ArrayList<String> lines = new ArrayList<String>();
    String line;
    while((line=br.readLine())!=null)
    {
        lines.Add(line);
    }
    br.close();
    if (lines.size() > 1) { // be sure that the last row exists (prevents indexoutexception)
        for (int i = 0; i < lines.size() - 1; i++) { // the - 1 excludes the last row
            String[]value = lines.get(i).split(",");
            String sql = "INSERT into main ([Ticket #], Status, Priority, Department, [Account Name]) "
                    + "values ('"+value[0]+"','"+value[1]+"','"+value[2]+"','"+value[3]+"','"+value[4]+"')";
            System.out.println(sql);
            PreparedStatement pst = null;
            try
            {
                pst = db.prepareStatement(sql);
                pst.executeUpdate();
            } finally {
                if(pst != null) {
                    pst.close();
                }
            }
        }
    }
}
catch(Exception e)
{
    JOptionPane.showMessageDialog(null, e);
}

Answer 2

如果可能，您可以使用Apache commons IO ReversedLinesFileReader并从最后读取CSV。然后你可以跳过第一行。

Answer 3

试试这个：

try
{
    BufferedReader br=new BufferedReader(new FileReader("v.csv"));
    String line;
    String firstFlag =true;
    while((line=br.readLine())!=null)
    {
     if (!firstFlag){

    String sql = "INSERT into main ([Ticket #], Status, Priority, Department, [Account      Name]) "
            + "values      ('"+value[0]+"','"+value[1]+"','"+value[2]+"','"+value[3]+"','"+value[4]+"')";
        System.out.println(sql);
        PreparedStatement pst = null;
        try
        {
            pst = db.prepareStatement(sql);
            pst.executeUpdate();
        }finally{
            if(pst != null){
                pst.close();
            }
        }
 }
     String[]value = line.split(",");
     firstFlag=false;
    }
     br.close();
}
catch(Exception e)
{
    JOptionPane.showMessageDialog(null, e);
}

Java - 将.csv导入数据库 - 排除最后一行

3 个答案: