java之jdbc_採用Statement根據條件查詢

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import java.sql.*;

//採用Statement根據條件查詢
public class QueryTest04 {
    public static void main(String[] args) {
        if (args.length == 0) {
            throw new IllegalArgumentException("參數非法，正確使用爲： Java QueryTest04 + 參數");
        }

        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {
            //第一步，加載數據庫驅動，不一樣的數據庫驅動程序不同
            Class.forName("oracle.jdbc.driver.OracleDriver");
            //第二部，獲得數據庫鏈接
            String dburl = "jdbc:oracle:thin:@localhost:1521:orcl";
            //String dburl = "jdbc:oracle:thin:@192.168.21.1:1521:orcl";
            //String dburl = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
            String userName = "system";
            String password = "wanwan";
            conn = DriverManager.getConnection(dburl, userName, password);
            //System.out.println(conn);

            //第三步，建立Statement，執行SQL語句
            stmt = conn.createStatement();
            //第四部，取得結果集
            //將條件作爲sql語句的一部分進行拼接
            //注意字符串必須採用單引號引發來
            //rs = stmt.executeQuery("select * from tb_student where sex like '" + args[0] + "'");
            String sql = "select * from tb_student where sex like '" + args[0] + "'";
            System.out.println("sql" + sql);
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                System.out.println(id + " , " + name);
            }


        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            //注意關閉原則：從裏到外


            try {
                if (rs != null) {
                rs.close();
                }
                if (stmt != null) {
                    stmt.close();
                }
                    if (conn != null) {
                    conn.close();
                    }
            } catch(SQLException e) {

            }

        }
    }
}