I need a simple SQL query to show a virtual/temporary table without creating it in the database.
I'm using PHP to create that query string with the data.
My current PHP code is,
$array = [
['id' => 1, 'name' => 'one'],
['id' => 2, 'name' => 'two'],
['id' => 3, 'name' => 'three']
];
$subQuery = "SELECT {$array[0]['id']} AS col1, '{$array[0]['name']}' AS col2";
for ($i=1; $i < count($array); $i++) {
$subQuery .= " UNION ALL SELECT {$array[$i]['id']}, '{$array[$i]['name']}'";
}
$sql = "WITH cte AS
(
{$subQuery}
)
SELECT col1, col2 FROM cte;";
echo $sql;
Its output is,
WITH cte AS
(
SELECT 1 AS col1, 'one' AS col2 UNION ALL SELECT 2, 'two' UNION ALL SELECT 3, 'three'
)
SELECT col1, col2 FROM cte;
// Output table from the SQL
col1 col2
1 one
2 two
3 three
I got the idea for this query from here.
But the problem with this query is that,
if I have 100 data in the $array, the UNION ALL part is getting included 100 times in the SQL. I feel like it is not a better SQL because it's like UNION 100 tables at the same time.
I also can create a temporary table (CREATE TEMPORARY TABLE table_name) instead of this WITH clause, but it is not a single query because I need another query to INSERT the records to that temporary table.
Can someone please help me to simplify this query in a better way?
When you use MySQL 8 you can use json_table expression like:
<?php
$array = [
['id' => 1, 'name' => 'one'],
['id' => 2, 'name' => 'two'],
['id' => 3, 'name' => 'three']
];
$data = json_encode($array);
$sql = "SELECT tbl.*
FROM JSON_TABLE(
'{\"data\":$data}',
'$.data[*]' COLUMNS (
id VARCHAR(40) PATH '$.id',
name VARCHAR(100) PATH '$.name')
) tbl";
echo $sql;
PHP online editor
The result of above query in MySQL 8.0 is:
+====+=======+
| id | name |
+====+=======+
| 1 | one |
+----+-------+
| 2 | two |
+----+-------+
| 3 | three |
+----+-------+
Related
I have an array, $submenus, in my app that I implode to a delimited string:
$subs = implode(',', $submenus);
The string will look something like this: 'ml_,nc_,msr_'. These values are stored in a field called group_prefix in my submenus table. Each submenu row has a unique group_prefix.
The following code builds menus and submenus from a database:
$menus = $this->Menus->find('all', [
'order' => ['Menus.display_order ASC'],
'conditions' => $conditions,
'contain' => [
'Submenus' => [
'conditions' => [
'Submenus.status' => 1,
'FIND_IN_SET("' . $subs . '", Submenus.group_prefix)'
],
]
]
]);
$this->set('menus', $menus);
It works fine until I add the FIND_IN_SET condition on Submenus. When I do, I get no submenus returned, just the main menus. Debug confirms that the string is formatted propery. Doesn't error out, I just get no resultset.
When I run the submenus query in MySQL, it works.
set #prefixes = 'ml_,nc_,msr_';
SELECT `id`, `name` FROM `submenus` WHERE `status` = 1 AND FIND_IN_SET(`submenus`.`group_prefix`, #prefixes);
+----+---------------------------+
| id | name |
+----+---------------------------+
| 4 | Mission Lessons Module |
| 5 | MSR Module |
| 8 | Work Authorization Module |
+----+---------------------------+
What am I missing?
Answer was to reverse the order of arguments in FIND_IN_SET.
Im trying to build a SQL Query that will select all orders from a table that matches options that i defined.
Databse i use: Mysql
Language: PHP
Basicly i have a array that looks like this.
[
[
"user_id" => 1,
"product_id" => 5548,
"variation_id" => 14
],
[
"user_id" => 1,
"product_id" => 5548,
"variation_id" => 15
],
[
"user_id" => 1,
"product_id" => 4422,
"variation_id" => 4
]
]
This means that the user(id: 1) has one product with the "id" of 5548, and then he also has 2 variations of that product that are "id" 14 and 15. You can also see that the same user owns the product(id:4422) that has variation(id:4).
I then have a "order_lines" table that looks like this
order_lines
+----+-----+---------+-----------------------------+
| id | uid | user_id | product_id | variation_id |
+----+-----+---------+-----------------------------+
| 1 | 1 | 1 | 5548 | 14 |
+----+-----+---------+-----------------------------+
| 2 | 2 | 1 | 5548 | 15 |
+----+-----+---------+-----------------------------+
| 3 | 3 | 1 | 4422 | 4 |
+----+-----+---------+-----------------------------+
| . | . | . | .... | .. |
+----+-----+---------+-----------------------------+
I now need a SQL Query that selects all the rows where there is a match between the user_id, product_id and variation_id that are defined in the array.
The output should contain all rows that meet these conditions.
I hope someone can pin me in the right direction.
I'm building in Laravel if you got the query builder just at your hand. Else i very much appreciate an SQL Query.
if I am getting you right, below code will help you, using just Core PHP
foreach($array as $arr){
$user_id = $arr['user_id'];
$prodct_id = $arr['prodct_id'];
$variation_id = $arr['variation_id'];
$query = "SELECT * FROM order_lines WHERE user_id = $userId AND product_id = $productId AND variation_id = $variationId";
$queryResult = mysql_fetch_assoc($query);
$yourCollection[] = $queryResult;
}
print_r($yourCollection);
Try below code to use Laravel Query Builder, below code will help you to get results for multiple users based on product and variation.
$qb_order_lines = DB::table('order_lines');
$where_condition = [
['user_id' => '', 'product_id' => '', 'variation_id' => ''],
];
foreach ($where_condition as $condition) {
$qb_order_lines->orWhere(function($query) use ($condition) {
$query->where('user_id', $condition['user_id'])
->where('product_id', $condition['product_id'])
->where('variation_id', $condition['variation_id']);
});
}
$obj_result = $qb_order_lines->get();
If you want to get it for only one user, use below code
$obj_result = DB::table('order_lines')
->where('user_id', $condition['user_id'])
->where('product_id', $condition['product_id'])
->where('variation_id', $condition['variation_id'])
->get();
You can modify the above query builders based on your requirements like select fields or group by.
Let me know if you need any help.
For anyone interesting.
My problem was that i needed to count of many matches that were between my array and my database.
Instead of selecting and outputting. I eneded up using sql count() function in a query, that did the job.
I'm trying to get all rows inside a foreach loop but it's not working as it should.
<?php
foreach ($locations_loop as $row):
$lr_id = $row["id"];
$stmtlr = $pdo->prepare("SELECT * FROM locations_rating WHERE l_id = {$lr_id}");
$stmtlr->execute();
$stlr_loop = $stmtlr->fetchAll(PDO::FETCH_ASSOC);
if (empty($stlr_loop)) {
$loc_rate[] = "0";
} else {
foreach($stlr_loop as $rowlr):
$loc_rate[] = $rowlr["stars"];
endforeach;
}
$rating_array = array_values($loc_rate);
$rating_avg = array_sum($rating_array) / count($rating_array);
?>
<?=round($rating_avg, 1);?>
<?php endforeach; ?>
$rating_avg outputs something else every time the script runs. It works fine outside a foreach loop tho. I tried to join the two table but no luck since it only outputs only one row.
I might be thinking too far out of the box, but this is just one technique that occurred to me which will ensure that all location ids will receive an average value in the result set.
Assuming $locations_loop (a poor name for a variable containing array type data, tbh) has the following data:
$locations_loop = [
['id' => 1],
['id' => 2],
['id' => 3],
['id' => 4],
];
And you have a database table with the following schema: (db-fiddle demo)
CREATE TABLE `locations_rating` (
`id` int(11) NOT NULL,
`l_id` int(11) NOT NULL,
`stars` int(11) NOT NULL DEFAULT 0
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `locations_rating` (`id`, `l_id`, `stars`) VALUES
(1, 3, 4),
(2, 2, 2),
(3, 1, 0),
(4, 2, 5),
(5, 3, 2),
(6, 1, 10);
Then you can get all of your data in one trip to the database by creating a "derived table" from your column of id values, then joining the database data to them. Something like this:
SELECT def.l_id,
ROUND(AVG(COALESCE(stars, 0)), 1) avg
FROM (
(SELECT 1 AS l_id)
UNION (SELECT 2)
UNION (SELECT 3)
UNION (SELECT 4)
) AS def
LEFT JOIN locations_rating AS loc ON def.l_id = loc.l_id
GROUP BY def.l_id
To do this with a prepared statement and bound parameters:
$locationIds = array_column($locations_loop, 'id');
$countIds = count($locationIds);
$fabricatedRows = implode(' UNION ', array_fill(0, $countIds, '(SELECT ? AS l_id)'));
$sql = "SELECT derived.l_id,
ROUND(AVG(COALESCE(stars, 0)), 1) avg
($fabricatedRows) AS derived
LEFT JOIN locations_rating as loc ON derived.l_id = loc.l_id
GROUP BY def.l_id";
$stmt = $pdo->prepare($sql);
$stmt->execute($locationIds);
var_export($stmt->fetchAll(PDO::FETCH_ASSOC));
Should output: (I tested this technique to be successful in my local environment)
[
['l_id' => 1, 'avg' => 5.0],
['l_id' => 2, 'avg' => 3.5],
['l_id' => 3, 'avg' => 3.0],
['l_id' => 4, 'avg' => 0.0],
]
I trying to join table using ONE query into sub array with column name => column value..
Short table(1) "users" structure with data:
user_id email ...
1 xxx#xx.xx ...
2 yyy#yy.yy ...
Short table(2) "users_permissions" structure with data:
user_id plugin_enter offers_view ...
1 1 0 ...
2 1 1 ...
If i use classic method - join left
SELECT `uperms`.*, `u`.*
FROM (`users` as u)
LEFT JOIN `users_permissions` as uperms ON `u`.`user_id` = `uperms`.`user_id`
I get classic output
[0] = array(
'user_id' => 1,
'email' => xxx#xx.xx,
'plugin_enter' => 1,
'offers_view' => 0
),
[1] = array(
'user_id' => 2,
'email' => yyy#yy.yy,
'plugin_enter' => 1,
'offers_view' => 1,
...
),
All i need is output into subarray as this:
[0] = array(
'user_id' => 1,
'email' => xxx#xx.xx,
'permissions => array(
'plugin_enter' => 1,
'offers_view' => 0
),
),
...
Is this possible to do with ONE query?
Table2 (permissions) contains about 60 columns. Is possible to CONCAT column's names with column value, if is joined to Table1 only one row?
MySQL doesn't have arrays or nested structures, so it's not possible to do this in SQL.
Change your query so you give all the fields from users_permissions a consistent naming style. Then you can use a PHP loop to collect all the array elements whose keys match that pattern into the permissions array.
Query:
SELECT u.*, up.plugin_enter AS perm_plugin_enter, up.offers_view AS perm_offers_view, ...
FROM users AS u
JOIN users_permissions AS up ON u.user_id = up.user_id
PHP:
foreach ($all_results as &$row) {
$permissions = array();
foreach ($row as $key => $value) {
if (strpos($key, 'perm_') === 0) {
$permission[substr($key, 5)] = $value;
unset($row[$key]);
}
}
$row['permissions'] = $permissions;
}
You could do it by concatenating all the column names and values in the table:
SELECT u.*, CONCAT_WS(',', CONCAT('plugin_enter:', plugin_enter), CONCAT('offers_view:', offers_view), ...) AS permissions
FROM users AS u
JOIN users_permissions AS up ON u.user_id = up.user_id
Then your PHP code can use explode() to split $row['permissions'] into array of name:value pairs, and then convert those to key=>value in the PHP array.
Another solution is to redesign your users_permissions table:
user_id permission_type value
1 plugin_enter 1
1 offers_view 0
...
2 plugin_enter 1
2 offers_view 1
...
Then you can query:
SELECT u.*, GROUP_CONCAT(permission_type, ':', value) AS permission
FROM users AS u
JOIN users_permissions AS up on u.user_id = up.user_id
Another possible sollution is to add prefixes to query.
Inspired by post: https://stackoverflow.com/a/9926134/2795923
SELECT `u`.*, ':prefix_start:', `uperms`.*, ':prefix_end:'
FROM (`users` as u)
LEFT JOIN `users_permissions` as uperms ON `u`.`user_id` = `uperms`.`user_id`
Output array looks like this:
[0] => array(
'user_id' => 1
'email' => xxx#xx.xx,
'prefix_start' =>
'plugin_enter' => 1,
'offers_view' => 0
'prefix_end' =>
)
...
Then easy PHP script to add all array data between prefix_start and prefix_end into own subarray.
I have two tables, a main one, and one that supports the main table, very very similar to what wordpress has, posts and posts_meta.
Main table:
id
title,
content
id | title | content
1 | one | content one
2 | two | content two
Meta table:
id
item_id
key
value
id | item_id | key | value
1 | 1 | template | single
2 | 1 | group | top
1 | 2 | template | page
2 | 2 | group | bottom
And my goal is, in the end, have an array with the data from the main table, merged with the meta table. example:
$data = array(
array(
'id' => 1,
'title' => 'one',
'content' => 'content one',
'template' => 'single',
'group' => 'top'
),
array(
'id' => 2,
'title' => 'two',
'content' => 'content two',
'template' => 'page',
'group' => 'bottom'
)
);
What is the best way to achieve this in a way that preforms good?
I am using PDO to connect to my database, and how Im doing right now is, I first query the data on the first table, and then for each result, i query the meta table, I use prepared statements for this, since it's suposed to be fast, but even so, it's harming the performance of my script.
Thank you
Instead of querying meta table for each result from first query
you should extract the ids from the first result:
$rows = q('SELECT * FROM posts');
$byIds = [];
foreach ($rows as &$row)
{
$byIds[$row['id']] =& $row;
}
and run second query:
$rows2 = q('SELECT * FROM posts_meta WHERE item_id IN (' . implode(',', array_keys($byIds)) . ')');
Then loop the results in PHP and merge with first query results.
foreach ($rows2 as $row2)
{
$byIds[$row2['item_id']][$row2['key']] = $row2['value'];
}
You have your merged results in $rows variable now:
var_dump($rows);
This way you will have only 2 db requests.
Please note that i have used $byIds as array of references so i dont have to search row with specific id in second loop. This way order of elements in $rows are preserved.