当数据库中存在更多时，ResultSet 仅返回一行

Question

我在该类中创建了一个名为 Executar_Query_Bd_Multiplos_Resultados 的 java 类，作为整数类型的 Conectar 方法 2 值（int Integer1，int Integer2）的参数。

查询接收到这些值：

"SELECT DS_ESTRATEGY, STRID_ID" +
    "FROM TB_BKOFFICE_ESTRATEGY" +
    "WHERE IN_STRATEGY_ID IN (" + Istrategy1 + "," + Istrategy2 + ")";

上述查询的结果存储在变量ls_command中。

在 Executar_Query_Bd_Multiplos_Resultados_Test 类中，我进行方法调用 (Connect) 和步骤 2 参数 (179, 319) 以及在屏幕上打印 String 类型的变量 codEstrategies 的命令。

但 Eclipse 只在控制台上显示 1 个结果。查询应该带来 2 个结果，而不是 1 个。这是 Java 类的代码和在 Oracle SQL Developer 中执行的查询结果。

public class Executar_Query_Bd_Multiplos_Resultados_Test {

@Before
public void setUp() throws Exception {

    Executar_Query_Bd_Multiplos_Resultados qr_2 = new Executar_Query_Bd_Multiplos_Resultados();
    String codEstrategias = qr_2.Conectar(179, 319);
    System.out.println("Estratégias: " + codEstrategias);

}

@After
public void tearDown() throws Exception {
}

@Test
public void test() {
}
}

public class Executar_Query_Bd_Multiplos_Resultados {
//Variáveis de BD
Connection conOracle = null;
Statement stmtOracle = null;
ResultSet rsetOracle = null;

public String Conectar(int Id_Estrategia1, int Id_Estrategia2) {

    String retorno = "#;-1;@";

    Boolean lb_continuar = true;
    //StringBuilder ls_comando = new StringBuilder();
    String ls_comando = new String();

    try {
        System.out.println("Conectando ao banco de dados Oracle...");
        String url = "";
        try {
            //conectando aos bancos de dados
            Class.forName("oracle.jdbc.driver.OracleDriver");
            url = "jdbc:oracle:thin:@10.5.12.116:1521:desenv01";
            DriverManager.setLoginTimeout(10);
            conOracle = (Connection) DriverManager.getConnection(url, "bkofficeadm", "bkofficeadmdesenv01");
        } catch (SQLException e) {
            System.out.println("falha SQL >> " + e.getMessage());
        } catch (Exception e) {
            //System.out.println("falha geral >> " + e.getMessage());
            e.printStackTrace();
            lb_continuar = false;
        }
        //String teste = "'BKO - Rep Conectividade'";
        if (lb_continuar) {
            System.err.println("Preparando comando...");
            System.out.println("");

            ls_comando = "SELECT  DS_ESTRATEGIA, ID_ESTRATEGIA"+
                                  " FROM TB_BKOFFICE_ESTRATEGIA"+
                                  " WHERE ID_ESTRATEGIA  IN (" + Id_Estrategia1 + ", " + Id_Estrategia2 + ")";  


            System.out.println(ls_comando);

            stmtOracle = conOracle.createStatement();
            stmtOracle.setQueryTimeout(10);
            rsetOracle = stmtOracle.executeQuery(ls_comando.replaceAll("\n", " ").trim());

            if(rsetOracle.next()) {
                retorno   = rsetOracle.getString(1);
            }              
            rsetOracle.close();
            stmtOracle.close();             
            /*
            Para comandos de Insert, Delete, ou Update
            --------------------------------------------------------
            stmtOracle = conOracle.createStatement();
            stmtOracle.setQueryTimeout(10);
            stmtOracle.execute(variavel_comando.toString());
            conOracle.commit();
            stmtOracle.close();
            */
        } 
    } catch (Exception ex) {
        System.out.println("Erro - " + ex.getMessage());
    } finally {
        try {
            if (rsetOracle != null) {
                rsetOracle.close();
            }
        } catch (Exception e) {
            System.out.println("Erro ao fechar rset - " + e.getMessage());
        }
        try {
            if (stmtOracle != null) {
                stmtOracle.close();
            }
        } catch (Exception e) {
            System.out.println("Erro ao fechar stmt - " + e.getMessage());
        }
        try {
            if (conOracle != null && !conOracle.isClosed()) {
                conOracle.close();
            }
            if (conOracle != null && !conOracle.isClosed()) {
                conOracle.close();
            }
        } catch (Exception e) {
            System.out.println("Erro ao fechar con  - " + e.getMessage());
        }
    }
    return retorno;

}
}

SQL Devleoper 查询的输出：

Eclipse 控制台的输出：

Answer 1

你正在这样做

if(rsetOracle.next()) {
    retorno   = rsetOracle.getString(1);
}   

运行一次

请考虑while：

List<String> retornos = new ArrayList<>();
while(rsetOracle.next()) {
    retornos.add(rsetOracle.getString(1));
}   

这将一直运行，直到您的行数用完为止。

如果将来发生类似情况，您需要将查询修改为select count(*) ... 并验证您在数据库工作台和您的 javacode 中获得相同的结果。然后，您至少会知道您的查询是正确的，而失败的是您的演示文稿。

---

注意：

我知道这个问题确实与其他问题重复。但是，这些很难搜索。我建议这是一个规范的答案。