How to get all items and their value by mysql query - mysql

Question

I have three mysql tables.
Table-01: table_item
In this table, all items with their corresponding ids are stored. Items are categorized in two categories. One is writing category (catid-1) and another is clothing category (catid-2).
---------------------------------------------
| id | catname | catid | itemid | itemname |
---------------------------------------------
║ 1 ║ writing ║ 1 ║ 1 ║ Pen ║
║ 2 ║ writing ║ 1 ║ 2 ║ Pencil ║
║ 3 ║ writing ║ 1 ║ 3 ║ Sharpner ║
║ 4 ║clothing ║ 2 ║ 4 ║ Pant ║
║ 5 ║clothing ║ 2 ║ 5 ║ shirt ║
║ 6 ║clothing ║ 2 ║ 6 ║ coat ║
║ 7 ║clothing ║ 2 ║ 7 ║ Tie ║
---------------------------------------------
Table-02: bid_item
Each year bid/tender is called for purchasing selective items from the above item table (table_item). So in this table, selected items, those are selected for bid/tender, are stored per year basis.
----------------------
║ id ║ itemid ║ year ║
----------------------
║ 1 ║ 1 ║ 2015 ║
║ 2 ║ 2 ║ 2015 ║
║ 3 ║ 3 ║ 2015 ║
║ 4 ║ 4 ║ 2015 ║
║ 5 ║ 5 ║ 2015 ║
║ 6 ║ 6 ║ 2015 ║
║ 7 ║ 1 ║ 2016 ║
║ 8 ║ 2 ║ 2016 ║
║ 9 ║ 3 ║ 2016 ║
║ 10 ║ 4 ║ 2016 ║
║ 11 ║ 7 ║ 2016 ║
----------------------
Table-03: bid_2015
After calling bid/Tender, rate of the corresponding companies for selected items are stored in this table. Each company will not give bid price for each items selected for a particular year. Tables are created according to the year alias. Here bid rate for year 2015 are stored as below:
--------------------------------
║ id ║ itemid ║ company ║ rate ║
--------------------------------
║ 1 ║ 1 ║ X ║ 2.0 ║
║ 2 ║ 2 ║ X ║ 2.2 ║
║ 3 ║ 3 ║ X ║ 1.0 ║
║ 4 ║ 4 ║ X ║ 10.0 ║
║ 5 ║ 5 ║ X ║ 15.0 ║
║ 6 ║ 1 ║ Y ║ 1.5 ║
║ 8 ║ 2 ║ Y ║ 2.0 ║
║ 9 ║ 3 ║ Y ║ 1.5 ║
║ 10 ║ 4 ║ Y ║ 12.0 ║
║ 11 ║ 6 ║ Y ║ 20.0 ║
--------------------------------
I need a html table (with input field) for data entry/edit for a particular year (Here, for 2015). Table will contain following:
1) Table will show each items for clothing catagory (catid-2)those are declared for the bid/tender for 2015.
2) If a company bids price, price will be in rate column, otherwise rate column will be blank. Administrator can either change the price (if entered wrong bid price) or add rate for other items which was not entered at first for a particular table.
So the look of the html table form will be as below:
HTML Form-Table (For Data Entry/Edit) : For Company-Y and clothing catagory for the year-2015
Company: (drop-down menu- Company-Y)
------------------------------------------------------
Item Name | Rate |
----------------------
Pant | 12.0 |
-----------------------
Shirt |
-----------------------
Coat | 20.0 |
-----------------------
============
Submit
============
As you can see Rate of Shirt is blank for Company-Y as this company did not give bid price for Shirt. If this company give the price of Shirt at later, rate can be entered and can update the table.
So what would be mysql query to get a html form table like above?
If I execute this query:
SELECT i.itemname,d.rate FROM table_item as i INNER JOIN bid_item as b ON i.itemid=b.itemid LEFT JOIN bid_2015 as d ON b.itemid=d.itemid WHERE i.catid=2 AND d.company='Y' AND b.year=2015
But the expected html table is not coming. As INNER and LEFT Join are used, Item Names are shown more than once in the form table.
What will be the effective mysql query to output a html form table like above?

Answer 1

this works for all data of company Y in 2015
select itemname,
rate
from table_item join bid_item on(table_item.itemid=bid_item.itemid and year=2015 and catid=2)
left join bid_2015 on( bid_2015.itemid=bid_item.itemid and
bid_item.itemid=table_item.itemid and company='Y' and year=2015 and catid=2)

Answer 2

This query will work fine.
SELECT i.itemname,
d.rate
FROM table_item as i
INNER JOIN bid_item as b ON i.itemid=b.itemid AND b.year=2015
LEFT JOIN bid_2015 as d ON b.itemid=d.itemid AND d.company='Y'
WHERE i.catid=2
Note:
When ever you are making LEFT/RIGHT joins on a table (say b as in
your example below). Never put conditions of table 'b' in WHERE
clause. It will act as INNER JOIN .
So the this code
SELECT i.itemname,
d.rate
FROM table_item as i
INNER JOIN bid_item as b ON i.itemid=b.itemid
LEFT JOIN bid_2015 as d ON b.itemid=d.itemid
WHERE i.catid=2 AND d.company='Y' AND b.year=2015
Act as INNER JOIN as given below.
SELECT i.itemname,
d.rate
FROM table_item as i
INNER JOIN bid_item as b ON i.itemid=b.itemid
INNER JOIN bid_2015 as d ON b.itemid=d.itemid
WHERE i.catid=2 AND d.company='Y' AND b.year=2015
Hope this helps.