我有一个表格，表示两种类型记录的常用值，我有另外两个表来保存彼此不同的数据。表1如下
银行
+-----------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| officer | varchar(32) | NO | | NULL | |
| bank | varchar(64) | NO | | NULL | |
| branch | varchar(64) | NO | | NULL | |
| amount | int(11) | NO | | NULL | |
| date | date | NO | | NULL | |
| sys_date | date | NO | | NULL | |
| source_document | varchar(360) | NO | | NULL | |
+-----------------+--------------+------+-----+---------+----------------+
machinery_banking
+----------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+-------+
| banking_id | int(11) | NO | | NULL | |
| engine_no | varchar(64) | NO | | NULL | |
| chassis_no | varchar(64) | NO | | NULL | |
| receipt_number | varchar(64) | NO | | NULL | |
| payment_type | int(11) | NO | | NULL | |
+----------------+-------------+------+-----+---------+-------+
spare_parts_banking
+----------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+-------+
| banking_id | int(11) | NO | | NULL | |
| invoice_number | varchar(32) | NO | | NULL | |
+----------------+-------------+------+-----+---------+-------+
输入到银行业务表的每个数据都有其他数据，每个表中有一个表machine_banking或spare_parts_banking。
我在银行表
中有以下数据+----+---------+------------+------------+-----------+------------+------------+------------------------------------------------------------------------------------------+
| id | officer | bank | branch | amount | date | sys_date | source_document |
+----+---------+------------+------------+-----------+------------+------------+------------------------------------------------------------------------------------------+
| 1 | prasad | Sampath | Kaduruwela | 234234234 | 2017-06-28 | 2017-06-28 | image |
| 2 | prasad | Commercial | Colombo | 234234234 | 2017-05-28 | 2017-05-28 | image |
+----+---------+------------+------------+-----------+------------+------------+------------------------------------------------------------------------------------------+
我在 machinery_banking
中有以下数据+------------+-----------+------------+----------------+--------------+
| banking_id | engine_no | chassis_no | receipt_number | payment_type |
+------------+-----------+------------+----------------+--------------+
| 1 | 2324234 | NL234234 | RAN234 | 1 |
+------------+-----------+------------+----------------+--------------+
spare_parts_banking 中的数据如下
+------------+----------------+
| banking_id | invoice_number |
+------------+----------------+
| 2 | INVRAN1 |
+------------+----------------+
我尝试了以下查询
SELECT a.id, a.officer, a.bank, a.branch, a.amount, a.date, a.sys_date, b.engine_no, b.chassis_no, a.source_document, c.invoice_number
FROM banking a,machinery_banking b, spare_parts_banking c
WHERE a.id = b.banking_id OR a.id = c.banking_id;
并最终得出以下结果
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
| id | officer | bank | branch | amount | date | sys_date | engine_no | chassis_no | source_document | invoice_number |
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
| 1 | prasad | Sampath | Kaduruwela | 234234234 | 2017-06-28 | 2017-06-28 | 2324234 | NL234234 | http://res.cloudinary.com/randeepa-com/image/upload/v1498455394/dmhxqal8hjcthhgav0n9.jpg | INVRAN1 |
| 2 | prasad | Commercial | Colombo | 234234234 | 2017-05-28 | 2017-05-28 | 2324234 | NL234234 | http://res.cloudinary.com/randeepa-com/image/upload/v1498455394/dmhxqal8hjcthhgav0n9.jpg | INVRAN1 |
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
我希望获得的结果如下
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
| id | officer | bank | branch | amount | date | sys_date | engine_no | chassis_no | source_document | invoice_number |
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
| 1 | prasad | Sampath | Kaduruwela | 234234234 | 2017-06-28 | 2017-06-28 | 2324234 | NL234234 | http://res.cloudinary.com/randeepa-com/image/upload/v1498455394/dmhxqal8hjcthhgav0n9.jpg | |
| 2 | prasad | Commercial | Colombo | 234234234 | 2017-05-28 | 2017-05-28 | | | http://res.cloudinary.com/randeepa-com/image/upload/v1498455394/dmhxqal8hjcthhgav0n9.jpg | INVRAN1 |
+----+---------+------------+------------+-----------+------------+------------+-----------+------------+------------------------------------------------------------------------------------------+----------------+
我可以使用什么查询来获得此结果
答案 0 :(得分：1)
为什么你有数据重复的原因是因为条件之间的OR
我相信这应该有用
SELECT a.id,
a.officer,
a.bank,
a.branch,
a.amount,
a.date,
a.sys_date,
b.engine_no,
b.chassis_no,
a.source_document,
c.invoice_number
FROM banking a
LEFT JOIN machinery_banking b
ON a.id = b.banking_id
LEFT JOIN spare_parts_banking c
ON a.id = c.banking_id;
同样转向新的JOIN语法，它更容易理解。
SQL连接语法 - Reference
答案 1 :(得分：0)
试试这个：
YOUR_LISTVIEW.setOnScrollListener(new OnScrollListener() {
private int currentVisibleItemCount;
private int currentScrollState;
private int currentFirstVisibleItem;
private int totalItem;
private LinearLayout lBelow;
@Override
public void onScrollStateChanged (AbsListView view,int scrollState){
// TODO Auto-generated method stub
this.currentScrollState = scrollState;
this.isScrollCompleted();
}
@Override
public void onScroll (AbsListView view,int firstVisibleItem,
int visibleItemCount, int totalItemCount){
// TODO Auto-generated method stub
this.currentFirstVisibleItem = firstVisibleItem;
this.currentVisibleItemCount = visibleItemCount;
this.totalItem = totalItemCount;
}
private void isScrollCompleted () {
if (totalItem - currentFirstVisibleItem == currentVisibleItemCount
&& this.currentScrollState == SCROLL_STATE_IDLE) {
/** To do code here*/
Dbref.orderByKey().startAt(oldestPostId).limitToFirst(10).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot child : dataSnapshot.getChildren()) {
oldestPostId = child.getKey();
String event_id = snapshot.child("details").child("event_id").getValue().toString();
e = new Event(event_id); //Event is a model class for list items
event.add(e);
Log.e("ShowEventInfo : ", "" + event_id);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
});
});