java - 用java打印SQL表

Question

我无法使用 JAVA 打印 SQL 表。我认为 JDBC Connection 没有问题。如何在控制台中打印表格？

Connection conn = null;
        Statement stmt = null;
        String url = "jdbc:oracle:thin:@localhost:1521:orcl";
        String user = "system";
        String pwd = "SSTTaarr00119922";
        ResultSet rs = null;

我做了 drivermanager getconnection。

System.out.println("start Connection");
        try {
            Class.forName("oracle.jdbc.OracleDriver");
            conn = DriverManager.getConnection(url, user, pwd);
        } catch (ClassNotFoundException e1) {
            System.out.println("Error loading driver:" + e1.toString());
            return;
        } catch (Exception e2) {
            System.out.println("Fail DB Connection:" + e2.toString());
            return;
        }

String sql = "SELECT * FROM dept";
try {
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
            System.out.println(sql);
 while (rs.next()) {
                String deptno = rs.getString(1);
                String dname = rs.getString(2);
                String Loc = rs.getString(3);

                System.out.println(deptno + dname + Loc);

            }

我无法在运行时打印。

Answer 1

在您的代码中，您缺少 try---catch block 中的 catch。下面的代码适用于 SQL Server

Connection conn = null;
Statement stmt = null;
ResultSet rs = null;

System.out.println("start Connection");
try {
    Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
    conn = DriverManager.getConnection("jdbc:sqlserver://localhost;databaseName=xxx;", "yyy", "zzz");
} catch (ClassNotFoundException e1) {
    System.out.println("Error loading driver:" + e1.toString());
    return;
} catch (Exception e2) {
    System.out.println("Fail DB Connection:" + e2.toString());
    return;
}

String sql = "SELECT * FROM [dbo].[User]";
try {
    stmt = conn.createStatement();
    rs = stmt.executeQuery(sql);
    System.out.println(sql);
    while (rs.next()) {
        String deptno = rs.getString(1);
        String dname = rs.getString(2);
        String Loc = rs.getString(3);

        System.out.println(deptno + dname + Loc);

    }
} catch (Exception e2) {
    System.out.println("Fail DB Connection:" + e2.toString());
}