I am trying to rewrite some MySQL queries in Knex.js, and I feel like I'm running into .raw at every turn, which feels counter to the reason I want to use Knex in the first place.
Is it possible to write the following query without using .raw?
SELECT
product,
SUM(revenue)
FROM orders
Using raw, it works to write:
knex()
.select(
'product',
knex.raw('SUM(revenue)')
)
.from('orders')
but the idea of using Knex was to avoid using MySQL query strings, so I'm hoping there's another way. Or does everyone just use .raw everywhere, and I'm misunderstanding something? Very possible, I'm new to this.
You can use the sum method.
sum — .sum(column|columns|raw) Retrieve the sum of the values of a
given column or array of columns (note that some drivers do not
support multiple columns). Also accepts raw expressions.
knex('users').sum('products')
Outputs:
select sum("products") from "users"
Probably be something like this:
knex()
.select('product')
.sum('revenue')
.from('orders')
You should adjust to your specific case. You might need to use something like groupBy('product') to get total revenue per product.
You should really go over knex's documentation, it's pretty good and straight forward and you definitely should not be using raw all the time.
You can even specify the returning sum column name like this:
knex(tableName)
.select('product')
.sum({ total: 'revenue' })
.groupBy('product');
Related
I have tried it in several ways but it doesn't work (seems like ignoring it). So what I tried:
$user->notes()->groupBy('title')->get();
Above way completely ignores groupBy and just returns collection of notes.
Note::where('user_id', $user->id)->groupBy('title')->get();
Exactly same output with this one too.
In my database.php, the database is set to 'strict' => false
I have also tried using raw db query, it returns it in a weird format (returns 1 row for each title when I use groupBy)
DB::table('notes')->where('user_id', $user->id)->groupBy('title')->get();
I have seen many people facing this issue however none of the suggested ways (above) solved the issue.
I can achieve what I want with using collection->each(function ($note) {...} ), however while there is groupBy to make achieve this easily with 1 line, why the heavy work..
Does anyone has any idea why it doesn't work?
you just need to call first the ->get() then the ->groupBy() method.
Thats because in a SQL Query you need to select first the elements, then group.
So your code need to be like:
DB::table('notes')->where('user_id', $user->id)->get()->groupBy('title');
Heres an example of a Group By Query:
SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
ORDER BY column_name(s);
go with select() and please add your group by field in select
e.g DB::table('notes')->select('title','Other_field')->where('user_id', $user->id)->groupBy('title')->get();
I am switching an application from PHP/MYSQL to Express and am using knex to connect to the MYSQL database. In one of my queries I use a statement like such (I have shortened it for brevity.)
SELECT ROUND(AVG(Q1),2) AS Q1 FROM reviews WHERE id=? AND active='1'
I am able to use ROUND if I use knex.raw but I am wondering if there is a way to write this using query builder. Using query builder makes dealing with the output on the view side so much easier than trying to navigate the objects returned from the raw query.
Here is what I have so far in knex.
let id = req.params.id;
knex('reviews')
//Can you wrap a ROUND around the average? Or do a Round at all?
.avg('Q1 as Q1')
.where('id', '=', id)
Thanks so much!
You can use raw inside select. In this case:
knex('reviews')
.select(knex.raw('ROUND(AVG(Q1),2) AS Q1'))
Check the docs here for more examples and good practices when dealing with raw statements.
Sorry about the title, I wasn't sure how to word it
I'm wanting to make a instant messaging system with PHP (I've done ajax for it) but I'm not sure how to get the query, I'm wanting something like this:
"SELECT * FROM messages WHERE user='$to' AND sender='$username' OR user='$username' AND sender='$to'"
Does anyone know if this is possible? Or a mysqli_fetch_array for two invididual queries on the same variable.
You can use parenthesis to use multiple operations to work as single operation in query. This is the typical approach anyway, and very useful for using multiple AND, OR operators in a query.
For you case, query should be like
"SELECT * FROM messages WHERE ( user='$to' AND sender='$username' ) OR ( user='$username' AND sender='$to' )"
Notice that tho we used 4 conditions, but with parenthesis we shrieked it into 2 separate conditions and ultimately one OR operation in the query.
Some good reading about this stuff at this article in case you want to dig it more
I am working on a problem where I need to add an OR clause to a set of existing conditions. The current conditions are built in a hash in a method and at the end, they are used in the where clause. Here is a simplified example:
...
conds.merge!({:users => {:archived => false}})
Model.where(conds)
I am trying to add an OR clause to the current set of conditions so it would be something like '(conditions) OR new_condition'. I'd like to add the OR statement without converting each addition to the conds hash into a string. That would be my last option. I was hoping someone has done something like this before (without using Arel). I seem to recall in Rails 2 there was a way to parse a conditions hash using a method from the model (something like Model.some_method(conds) would produce the where clause string. Maybe that would be a good option to just add the OR clause on to that string. Any ideas are appreciated. Thank you for your help!
I found a way to do what I needed. Instead of changing all of the conditions that I am building, I am parsing the conditions to SQL using sanitize_sql_for_conditions. This is a private method in ActiveRecord, so I had to put a method on the model to allow me to access it. Here is my model method:
def self.convert_conditions_hash_to_sql(conditions)
self.sanitize_sql_for_conditions(conditions)
end
So, once I convert my conditions to text, I can add my OR clause (along with the appropriate parentheses) to the end of the original conditions. So, it would go something like this:
Model.where('(?) OR (model.type = ? AND model.id IN(?))', Model.convert_conditions_hash_to_sql(conds), model_type, model_id_array)
The following doesn't work, but something like this is what I'm looking for.
select *
from Products
where Description like (#SearchedDescription + %)
SSRS uses the # operator in-front of a parameter to simulate an 'in', and I'm not finding a way to match up a string to a list of strings.
There are a few options on how to use a LIKE operator with a parameter.
OPTION 1
If you add the % to the parameter value, then you can customize how the LIKE filter will be processed. For instance, your query could be:
SELECT name
FROM master.dbo.sysobjects
WHERE name LIKE #ReportParameter1
For the data set to use the LIKE statement properly, then you could use a parameter value like sysa%. When I tested a sample report in SSRS 2008 using this code, I returned the following four tables:
sysallocunits
sysaudacts
sysasymkeys
sysaltfiles
OPTION 2
Another way to do this that doesn't require the user to add any '%' symbol is to generate a variable that has the code and exceute the variable.
DECLARE #DynamicSQL NVARCHAR(MAX)
SET #DynamicSQL =
'SELECT name, id, xtype
FROM dbo.sysobjects
WHERE name LIKE ''' + #ReportParameter1 + '%''
'
EXEC (#DynamicSQL)
This will give you finer controller over how the LIKE statement will be used. If you don't want users to inject any additional operators, then you can always add code to strip out non alpha-numeric characters before merging it into the final query.
OPTION 3
You can create a stored procedure that controls this functionality. I generally prefer to use stored procedures as data sources for SSRS and never allow dynamically generated SQL, but that's just a preference of mine. This helps with discoverability when performing dependency analysis checks and also allows you to ensure optimal query performance.
OPTION 4
Create a .NET code assembly that helps dynamically generate the SQL code. I think this is overkill and a poor choice at best, but it could work conceivably.
Have you tried to do:
select * from Products where Description like (#SearchedDescription + '%')
(Putting single quotes around the % sign?)
Dano, which version of SSRS are you using? If it's RS2000, the multi-parameter list is
not officially supported, but there is a workaround....
put like this:
select *
from tsStudent
where studentName like #SName+'%'
I know this is super old, but this came up in my search to solve the same problem, and I wound up using a solution not described here. I'm adding a new potential solution to help whomever else might follow.
As written, this solution only works in SQL Server 2016 and later, but can be adapted for older versions by writing a custom string_split UDF, and by using a subquery instead of a CTE.
First, map your #SearchedDescription into your Dataset as a single string using JOIN:
=JOIN(#SearchedDedscription, ",")
Then use STRING_SPLIT to map your "A,B,C,D" kind of string into a tabular structure.
;with
SearchTerms as (
select distinct
Value
from
string_split(#SearchedDescription, ',')
)
select distinct
*
from
Products
inner join SearchTerms on
Products.Description like SearchTerms.Value + '%'
If someone adds the same search term multiple times, this would duplicate rows in the result set. Similarly, a single product could match multiple search terms. I've added distinct to both the SearchTerms CTE and the main query to try to suppress this inappropriate row duplication.
If your query is more complex (including results from other joins) then this could become an increasingly big problem. Just be aware of it, it's the main drawback of this method.