java列结果与预期不符

Question

在这里，我使用这个查询将两个表连接起来，并将其合并为一个结果

String query = "SELECT * FROM tb_barang RIGHT JOIN tb_jenis ON tb_barang.kd_jenis = tb_jenis.kd_jenis ";

这是我的两个表的表结构

表“tb_barang”
https://i.stack.imgur.com/6OpeC.png

和表“tb_jenis”
https://i.stack.imgur.com/UhLty.png

我期待这样的输出
https://i.stack.imgur.com/zhtHx.png

然而，当我获取列“jenis”时，java会向其中抛出异常，因为要么超出范围，要么找不到列

然后我使用以下命令检查该列是否存在：

ResultSet resTabel = new mysqlDriver().getKolomBarangList();
            ResultSetMetaData metaData = resTabel.getMetaData();
            int colCount = metaData.getColumnCount();
            if (resTabel.next()) {
        for (int i = 1; i <= colCount; i++) {
        System.out.println("Col(" + i + ") '" + metaData.getColumnName(i) + "' value:" + resTabel.getString(i));
    }

输出：

Col(1) 'kd_barang' value:BAR0000
Col(2) 'nama_barang' value:A
Col(3) 'kd_jenis' value:J_1
Col(4) 'jumlah_barang' value:1
Col(5) 'harga_satuan' value:1
BUILD SUCCESSFUL (total time: 35 seconds)

如何做到这一点？谢谢回复

Answer 1

显然，由于@forpas，我没有输入方法名。getKolomBarangList()指的是表tb_barang的字段名，不执行“JOIN”子句

protected ResultSet getBarangList()throws SQLException, NullPointerException, ClassNotFoundException{
        String query = "SELECT * FROM tb_barang RIGHT JOIN tb_jenis ON tb_barang.kd_jenis = tb_jenis.kd_jenis ";
        if(resForListBarang == null){
            resForListBarang = alwaysDoResultSet(query);
        }
        return resForListBarang;
    }

    protected ResultSet getKolomBarangList() throws SQLException, Exception{
        String query = "SELECT * FROM tb_barang";
        if(getBarangKolom == null){
            getBarangKolom = alwaysDoResultSet(query);
        }
        return getBarangKolom;
    }

而getBarangList()的输出是预期的最终结果

Col(1) 'kd_barang' value:BAR0000
Col(2) 'nama_barang' value:A
Col(3) 'kd_jenis' value:J_1
Col(4) 'jumlah_barang' value:1
Col(5) 'harga_satuan' value:1
Col(6) 'kd_jenis' value:J_1
Col(7) 'jenis' value:Pakan Hewan
BUILD SUCCESSFUL (total time: 21 seconds)

感谢所有帮助我的人：）