數據庫結果輸出假脫機

Question

如何將單個SELECT sql語句的EACH行結果後臺處理爲不同的輸出文件？ 舉例來說，如果我有

SELECT * FROM myTable WHERE columnId < 45;

while (rs.next()) { 
    result of row1 goes to row1.txt; 
    result of row2 goes to row2.txt; 
    result of row3 goes to row3.txt; 
    result of row4 goes to row4.txt; 
} 

Answer 1

我會做這種方式（不生產質量的代碼，但一個基本的想法）：

private String spoolRow(ResultSet currentRow) 
{ 
    // Append each attribute to a StringBuilder in a nicely formatted way 
    // and return. 
} 

private void myMethod(....) 
{ 
    ... 
    ... 
    FileOutputStream fos; 
    String fileName; 
    int counter = 1; 
    while (rs.next()) { 
     fileName = "row" + counter + ".txt"; 
     fos = new FileOutputStream(fileName); 
     fos.write(spoolRow(rs)); 
     fos.close(); 
     counter++; 
    } 
    ... 
    ... 
} 

如果您還需要在列頭，然後ResultSetMetaData從resultSet.getMetaData()可用於獲取列名稱，準備標題並寫入數據行之前寫入每個文件。