I have a view where i need to get list of all dishes from menu table according to main_menuid for a particular user, But here i need to put some conditions
Currently i am using 3 tables for the entire process (table view for all 3 is given at the end)
1) main_menu
2) menu
3) cart
1) I need to get list of dishes according to main_menuid
so here if i need a list of dishes below MM1, so list of dishes that i should get from menu table is (main_menuid is the id of main_menu table)
id main_menuid dish
1 1 D1
2 1 D2
3 1 D3
code i used to get the above data is
$sql = "select * from menu where main_menuid = '".$mainmenuid."'";
$result = mysqli_query($con, $sql);
if (mysqli_num_rows($result) > 0)
{
while($row = mysqli_fetch_assoc($result))
{
print_r($row);
}
}
2) i will also have a userid with me so now i need to display the above list to a particular user (Let the userid be "1"), but if he already has added any of the above product to cart earlier then it's quanity should also get fetched from cart and for rest of the items(that are not added by him to the cart but is present in the above list) the quantity will be null, so the resulting view should be like this (menuid is the id of menu table)
id main_menuid menuid dish quantity userid
1 1 1 D1 3 1
2 1 1 D2 2 1
3 1 1 D3 0 1
code that i tried for the above result is (but it didn't gave me the desired result)
SELECT menu.main_menuid, menu.dish, cart.userid,
cart.quantity
FROM menu
LEFT JOIN cart ON menu.id=cart.menuid
WHERE main_menuid = '".$main_menuid."' and userid = '".$userid."'
Below is a sample view of all the tables that are being used in the above process
main menu
id mainmenu_name
1 MM1
2 MM2
3 MM3
4 MM4
menu
id main_menuid dish
1 1 D1
2 1 D2
3 1 D3
4 2 D4
5 3 D5
6 4 D6
cart
id userid menuid dish main_menuid quantity
1 1 1 D1 1 3
2 1 2 D2 1 2
3 2 1 D1 1 3
can anyone please tell how to achieve the desired result (DBMS: mysql)
move userID to the join as it is eliminating the null values generated from the left join.
SELECT menu.main_menuid, menu.menuid, menu.dish, cart.userid,
cart.quantity
FROM menu
LEFT JOIN cart ON menu.id=cart.menuid
and userid = '".$userid."'
WHERE main_menuid = '".$main_menuid."'
However this implies you want some dishes not associated to the user so userID will be NULL in some cases.
Why does this work and not in the where clause? Because the filter is applied BEFORE the join. This allows the null values which would occur as a result of the left join to remain.
You can't get userid from your cart table directly, if the desired menu item is not in cart. So your WHERE clause filters out these records. Try this request:
SELECT menu.main_menuid, menu.menuid, menu.dish, IF(ISNULL(cart.userid), ".$main_menuid.", cart.userid) AS userid,
IF(ISNULL(cart.quantity), 0, cart.quantity) AS quantity
FROM menu
LEFT JOIN cart ON menu.id=cart.menuid
WHERE menu.main_menuid = '".$main_menuid."'
I think the problem is on the LEFT JOIN. You should do this way:
LEFT JOIN cart ON menu.id=cart.menuid and cart.dish = menu.dish
EDIT
When you do this way, the userid column will be null at the last line, to avoid this, on select you should put something like this:
SELECT menu.main_menuid, menu.dish,
COALESCE(cart.quantity, 0), -- will put 0 when null
COALESCE(cart.userid, '".$userid."') as userid -- will put '".$userid."' when null
Related
I need a help with projecting my database. The purpose of this database will be to show offers in different categories. There are 1-6 categories to each item. There are around 80 categories types, so I decided to make three tables as below:
table1:
ID Item_id
1 1
2 2
3 3
4 4
5 5
table2:
ID Item_id Category
1 1 cat55
2 1 cat56
3 1 cat57
4 1 cat58
5 2 cat42
6 2 cat43
7 2 cat44
8 2 cat45
9 3 cat42
etc.
table3:
Category_id category_name
cat55 apples
cat56 oranges
cat57 bananas
cat58 pineapples
Am I doing this right? I've got a problem to make proper sql query to show my categories in php, because when I use this query:
SELECT table1.*, table2.*, table3.*
FROM table1
INNER JOIN table2
ON table1.item_id = table2.item_id
INNER JOIN table3
ON table2.category=table3.category_id
It only gives me the first category name, when I need all of them and show them like this:
Item 1: apples, oranges, bananas, pineapples
Item 2: cat42, cat43, cat44, cat45
Item 3: cat42
What am I doing wrong? Is it wrong query or I need to change the database structure to like this
table 1 and 3 unchanged
table 2:
ID Item_id c1 c2 c3 c4 c5 c6
1 1 cat55 cat56 cat57 cat58 null null
2 2 cat42 cat43 cat44 cat45 null null
3 3 cat42 null null null null null
I'm using foreach loop, so I can do only one query, I know that more queries are possible, but I need to make it as simple as possible.
If you want to fetch all names in single row for each item, following query will work:
SELECT table1.Item_Id,Group_Concat(t3.category_name separator ',') as Category_Name
FROM table1
INNER JOIN table2
ON table1.item_id = table2.item_id
INNER JOIN table3
ON table2.category=table3.category_id
Group by table1.Item_Id;
I don't find any problem in your DB Structure.
Hope it helps!
I have multiple tables with orders and deliveries and I want to get only open orders (only those orders that do not have records in delivery table).
So, my tables look like:
Orders table (sh_comenzi):
id partner
1 Partner X
2 Partner Y
3 Partner Z
4 Partner Q
Order lines table (sh_comenzi_pos) where idc is the id of sh_comenzi table
id idc cPos quantity
1 1 1 5
2 1 2 10
3 1 3 20
4 2 1 10
5 2 2 15
6 3 1 10
7 3 2 5
8 3 3 8
9 4 1 15
The deliveries items table is (sh_delivery_items)
id idc cPos
1 1 1
2 1 3
3 2 2
4 3 1
5 3 2
6 3 3
The desired result should give me an output of open orders just like this:
id partner
1 Partner X
2 Partner Y
4 Partner Q
The result doesn't have to keep track o quantities, just on lines level. If one line from orders exists in sh_delivery_items then that line is closed.
I tried something like this:
SELECT DISTINCT sh_comenzi.id, partner FROM sh_comenzi
LEFT JOIN sh_comenzi_pos ON sh_comenzi.id = sh_comenzi_pos.idc
LEFT JOIN sh_delivery_items ON (sh_comenzi_pos.idc = sh_delivery_items.idc AND sh_comenzi_pos.cPos = sh_delivery_items.cPos)
WHERE sh_comenzi.id IS NOT NULL
ORDER BY sh_comenzi.id DESC
Could someone help me?
This is the query you need:
SELECT DISTINCT c.*
FROM sh_comenzi c
INNER JOIN sh_comenzi_pos p
ON c.id = p.idc
LEFT JOIN sh_delivery_items di # 'di' from 'delivery items'
ON p.idc = di.idc AND p.cPos = di.cPos
WHERE di.id IS NULL # keep only not-delivered items
How it works
It combines all the orders (table sh_comenzi) with their line items (table sh_comenzi_pos). The INNER JOIN will leave out the empty orders (if any); if you need them then use LEFT JOIN instead.
Next, each row (order, line item) is combined with the delivery information (table sh_delivery_items) using the pair of columns (idc, cPos). The LEFT JOIN ensures all the rows from the left side table (or result set) appear in the final result set; if a row from the right side table cannot be found to match the row from the left, a row full of NULLs is used instead. This happens for the line items that were not delivered yet (there is no record for them in sh_delivery_items).
Then, the WHERE clause keeps only the rows having NULLs in the di table (sh_delivery_items), i.e. the line items that were not delivered, together with the orders that own them.
Finally, SELECT DISTINCT c.* selects only the columns from the orders table (sh_comenzi) and DISTINCT ensures each order appear only once. Otherwise, each order appears once for each of its line items that was not delivered.
Complete the query yourself with the desired ORDER BY clause.
I have a table categories which contains the columns ID & ParentID I would like to add a field called Level, which states which level in the category tree each category is.
I think i found my solution but it is in sql not mysql. So i have been converting it to the correct syntax. However, i think im missing a step. So, here is my code:
ALTER TABLE categories DROP Level;
ALTER TABLE categories ADD Level INT NULL;
UPDATE categories
SET Level = 0
WHERE ParentID IS NULL;
UPDATE categories AS A
INNER JOIN categories B ON A.ParentID = B.ID
SET A.Level = B.Level + 1
WHERE A.Level IS NULL AND
B.Level IS NOT NULL;
I think the problem may lie in the fact that in my DB The order of the categories do not come in any specific order, what i mean is as follows:
ID ParentID
2 NULL 0
4 55
7 2
.....more categories
55 2
So what i would like it do do is:
ID Parent Level
2 NULL 0
3 55 2
7 2 1
....
55 2 1
However, i think, but i might be wrong, is that i need to either order by ParentID first before i do the last operation, or my query is missformed.
I am not getting any errors however, but just not getting the results i am expecting this is what im getting;
ID Parent Level
2 NULL 0
3 55 NULL
7 2 1
....
55 2 1
Any ideas?
The question is how many levels do u have?
If they are 3 levels than u can do it like this
ALTER TABLE categories DROP Level;
ALTER TABLE categories ADD Level INT NULL;
UPDATE categories SET Level = 0 WHERE ParentID IS NULL;
UPDATE categories SET level = 1 where parentID = 2;
UPDATE categories SET level = 2 where parentID > 2;
I have a database that looks like this with two tables
Items
id | Title
-----------------------------
1 Bus
2 Plane
3 Jet
4 Shoes
5 Chair
Sorting
id | CatID | ItemID | SortOrder
-------------------------------------------------------------------------------
1 3 3 3
2 3 2 1
3 3 4 2
4 3 1 0
5 4 5 4
I can't figure out how to list the Titles of the ITEMS table based on the "SortOrder" Column of the SORTING table.
Here is what I tried so far:
SELECT *
FROM Items
LEFT JOIN Sorting ON Items.id = Sorting.ItemID
WHERE Sorting.CatID = 3
ORDER BY Sorting.SortOrder
I'm not sure what I'm doing wrong
EDIT
It looks like the MySQL query is correct, the problem is happening because when I output the $row['id'] of the Items Table it is incorrect. I have an Ajax PHP update that is updating the database based on the id of an li tag.
Any ideas why the $row['id'] is outputting incorrectly? I think it has something to do with the Items.id = Sorting.ItemID
This works as expected - SQLFiddle DEMO:
SELECT i.*, s.SortOrder
FROM items i, sorting s
WHERE i.id = s.ItemID
AND s.CatID = 3
ORDER BY s.SortOrder
Try
SELECT *
FROM Items
LEFT JOIN Sorting ON Items.id = Sorting.ItemID
WHERE Sorting.CatID = 3
ORDER BY Sorting.SortOrder ASC
add DESC or ASC in ORDER BY clause.
if you use ASC then sorted result will be 0 1 2 3 4 for SortOrder.
sample php code to get title
<?php
$query = mysqli_query(above_query)or die(mysqli_error());
while($result = mysqli_fetch_assoc($query))
{
echo $result['title']. '<br/>';
}
I have written a query which returns all records with some many-to-many joins correctly for the entire set or an individual article using WHERE a.id = ?
SELECT a.id, date_added, title, content, category_id, person_id, organization_id, c.name AS category_name, firstname, lastname, o.name AS organization_name
FROM articles AS a
LEFT OUTER JOIN articles_categories AS ac ON a.id=ac.article_id
LEFT OUTER JOIN categories AS c ON c.id=ac.category_id
LEFT OUTER JOIN articles_people AS ap ON a.id=ap.article_id
LEFT OUTER JOIN people AS p ON p.id=ap.person_id
LEFT OUTER JOIN articles_organizations AS ao ON a.id=ao.article_id
LEFT OUTER JOIN organizations AS o ON o.id=ao.organization_id
ORDER BY date_added
BUT!
I've hit a brick wall trying to work out how to limit the articles to a specific number of IDs, for working with pagination.
I'm ideally trying to use as simple and clear SQL statements as possible because I'm using the codeigniter framework with their active record class.
http://codeigniter.com/user_guide/database/active_record.html
Would really appreciate some help as I don't want to revert to using multiple queries for this as I've tried to reduce it down to a single query for database efficiency.
Have search around and tried some alternatives but nothing seems to work. Many thanks!
For example the results I return are like this
---------------------------------------------------------------------
id title category_id person_id organization_id
---------------------------------------------------------------------
1 test 1 1 1
1 test 2 1 1
1 test 1 2 1
1 test 1 1 2
1 test 5 1 1
1 test 8 1 1
1 test 1 4 1
1 test 1 4 2
1 test 1 1 1
2 test 2 2 1 1
2 test 2 1 2 1
2 test 2 1 1 2
2 test 2 5 1 1
2 test 2 8 1 1
2 test 2 1 4 1
2 test 2 1 4 2
I need the results like this so that I can create sub-arrays in the php like this:
$articles = $query->result_array();
$output = array();
foreach ($articles as $article) {
// set up article details
$article_id = $article['id'];
// add article details
$output[$article_id]['article_id'] = $article_id;
$output[$article_id]['date_added'] = $article['date_added'];
$output[$article_id]['title'] = $article['title'];
$output[$article_id]['content'] = $article['content'];
// set up people details and add people array with details if exists
if (isset($article['person_id'])) {
$person_id = $article['person_id'];
$output[$article_id]['people'][$person_id]['person_id'] = $person_id;
$output[$article_id]['people'][$person_id]['lastname'] = $article['lastname'];
$output[$article_id]['people'][$person_id]['firstname'] = $article['firstname'];
}
// set up organizations details and add organizations array with details if exists
if (isset($article['organization_id'])) {
$organization_id = $article['organization_id'];
$output[$article_id]['organizations'][$organization_id]['organization_id'] = $organization_id;
$output[$article_id]['organizations'][$organization_id]['organization_name'] = $article['organization_name'];
}
// set up categories details and add categories array with details if exists
if (isset($article['category_id'])) {
$category_id = $article['category_id'];
$output[$article_id]['categories'][$category_id]['category_id'] = $category_id;
$output[$article_id]['categories'][$category_id]['category_name'] = $article['category_name'];
}
}
But if I just use LIMIT (with offset etc) 1
the results I get are
---------------------------------------------------------------------
id title category_id person_id organization_id
---------------------------------------------------------------------
1 test 1 1 1
instead of
---------------------------------------------------------------------
id title category_id person_id organization_id
---------------------------------------------------------------------
1 test 1 1 1
1 test 2 1 1
1 test 1 2 1
1 test 1 1 2
1 test 5 1 1
1 test 8 1 1
1 test 1 4 1
1 test 1 4 2
1 test 1 1 1
which is my desired result.
OK, so finally I worked out how it is possible.
Thought i'd include it here in case anyone else has the same problem.
Changing this line
FROM articles AS a
to this
FROM (SELECT * FROM articles LIMIT 5,3) AS a
does what I wanted.
So, why don't you use OFFSET 0,10 and LIMIT *number_of_results* in the SQL Query? (if I understood the question)
Specific number of IDs... WHERE ID IN (2,4,6,8)... ?
Are you using codeigniter's pagination?
http://codeigniter.com/user_guide/libraries/pagination.html
You can easily limit the number of records that are being returned using the MySQL LIMIT clause. This can be achieved like the following with your sample query.
SELECT a.id, date_added, title, content, category_id, person_id, organization_id, c.name AS category_name, firstname, lastname, o.name AS organization_name
FROM articles AS a
LEFT OUTER JOIN articles_categories AS ac ON a.id=ac.article_id LEFT OUTER JOIN categories AS c ON c.id=ac.category_id
LEFT OUTER JOIN articles_people AS ap ON a.id=ap.article_id LEFT OUTER JOIN people AS p ON p.id=ap.person_id
LEFT OUTER JOIN articles_organizations AS ao ON a.id=ao.article_id LEFT OUTER JOIN organizations AS o ON o.id=ao.organization_id
ORDER BY date_added
LIMIT 10
Where 10 is the number of records you wish to display. The MySQL LIMIT clause allows you to specify a limit of the number of records and an initial offset. Like so:
LIMIT <offset>,<limit>
In your case <offset> would be the current page * the number of records on a page. <limit> would be the number of records you would like to display per page.