[英]Column result doesn't as be expected
在這里,我有查詢連接兩個表,並使用此查詢將其合並為一個結果
String query = "SELECT * FROM tb_barang RIGHT JOIN tb_jenis ON tb_barang.kd_jenis = tb_jenis.kd_jenis ";
這是兩個表的表結構
表“tb_barang”
https://i.stack.imgur.com/6OpeC.png
和表“tb_jenis”
https://i.stack.imgur.com/UhLty.png
我期待這樣的輸出
https://i.stack.imgur.com/zhtHx.png
但是,當我使用“jenis”列時,java會將異常拋入其中,因為要么超出范圍,要么找不到列。
然后我使用以下方法檢查列是否存在:
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));
}
輸出:
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)
怎么做到這一點? 謝謝你的回復
顯然,由於@forpas,我很想輸入方法名稱。 getKolomBarangList()
引用表tb_barang
字段名稱而不執行“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;
}
並且getBarangList()
的輸出被期望作為最終結果
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)
感謝任何幫助我的人:)
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