淺談如何解決微軟自帶JDBC的resultset缺陷
微軟自帶的3個驅動包分別為:msbase.jar,mssqlserver.jar,msutil.jar
微軟JDBC resultset驅動的缺點:
(1)如果采用jdbc-odbc驅動,那么就必須按照查詢順序來一次讀取(不論有沒有image或text類型)
(2)如果采用微軟提供的ms sql server jdbc driver,如果查詢語句中,不存在image或text類型字段,那么可以按照無序獲取
(3)如果采用微軟提供的ms sql server jdbc driver,如果查詢語句中,存在image或text類型字段,那么就必須按照順序讀取,否則就會報告Driver]ResultSet can not re-read row data for column之類的錯誤
測試方法和代碼如下:
數據庫表:TestTable
表字段及類型:
guid char(38)
title varchar(100)
content Text
username varchar(20)
JDBC resultset代碼
- public static void main(String[] args) {
- // TODO Auto-generated method stub
- String url = "jdbc:microsoft:sqlserver://192.168.5.20:1435;DatabaseName=emos2.2";
- String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
- try {
- Class.forName(driver);
- Connection conn = DriverManager.getConnection(url, "sa", "1234");
- if (conn.isClosed() == true) {
- System.out.println("SomeThing goes wrong ");
- }
- PreparedStatement st = conn.prepareStatement("select * from TestTable");
- ResultSet rs = st.executeQuery();
- while(rs.next()){
- System.out.println(rs.getString("guid"));
- System.out.println(rs.getString("username"));
- System.out.println(rs.getBinaryStream("content"));
- }
- } catch (ClassNotFoundException e) {
- System.out.println("SomeThing wrong ");
- System.out.println(e);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- public static void main(String[] args) {
- // TODO Auto-generated method stub
- String url = "jdbc:microsoft:sqlserver://192.168.5.20:1435;DatabaseName=emos2.2";
- String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
- try {
- Class.forName(driver);
- Connection conn = DriverManager.getConnection(url, "sa", "1234");
- if (conn.isClosed() == true) {
- System.out.println("SomeThing goes wrong ");
- }
- PreparedStatement st = conn.prepareStatement("select * from TestTable");
- ResultSet rs = st.executeQuery();
- while(rs.next()){
- System.out.println(rs.getString("guid"));
- System.out.println(rs.getString("username"));
- System.out.println(rs.getBinaryStream("content"));
- }
- } catch (ClassNotFoundException e) {
- System.out.println("SomeThing wrong ");
- System.out.println(e);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
- 而第三方的驅動jtds1.2很好的解決了這些bug
- Java代碼
- public static void main(String[] args) {
- String url = "jdbc:jtds:sqlserver://192.168.5.20:1435/emos2.2";
- String driver = "net.sourceforge.jtds.jdbc.Driver";
- try {
- Class.forName(driver);
- Connection conn = DriverManager.getConnection(url, "sa", "1234");
- if (conn.isClosed() == true) {
- System.out.println("SomeThing goes wrong ");
- }
- PreparedStatement st = conn.prepareStatement("select * from TestTable");
- ResultSet rs = st.executeQuery();
- while(rs.next()){
- System.out.println(rs.getString("guid"));
- System.out.println(rs.getString("username"));
- System.out.println(rs.getBinaryStream("content"));
- }
- } catch (ClassNotFoundException e) {
- System.out.println("SomeThing wrong ");
- System.out.println(e);
- } catch (SQLException e) {
- e.printStackTrace();
- }
- }
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