Question

在这里我有查询以联接两个表，并通过使用此查询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

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

但是，当我使用列“ jenis”时，java抛出了异常，因为它超出范围或未找到列。

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)

如何实现？感谢您的答复

Answer 1

显然，由于@forpas，我很想念方法名称。 getKolomBarangList()引用表tb_barang的字段名称，并且不执行“ 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;
    }

getBarangList()的输出应作为最终结果

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)

感谢帮助我的人：）

列结果与预期不符

1 个答案: