logo
Tags down

shadow

Is possible that : "SELECT COUNT (*) < SELECT COUNT (VALUE)?"


By : Yusri Yusron
Date : September 15 2020, 07:00 PM
like below fixes the issue COUNT(*) counts every record, while COUNT(value) only takes in account non-null values. For a given dataset, COUNT(*) cannot be smaller than COUNT(value), however it may be greater.
Consider the following dataset:
code :
val
1
2
null
select count(*), count(val) from t
count(*) | count(val)
-------: | ---------:
       3 |          2


Share : facebook icon twitter icon

"Select count (*)" vs count of results from "Select 1" : which is more efficient way to get the rows


By : TomQuijote
Date : March 29 2020, 07:55 AM
this one helps. select count is faster - because the database only needs to return a single number rather than a potentially long list.

How do I Select "sales count" for each item and show as "popularity" in Select ALL "design"


By : mjsalvilla
Date : March 29 2020, 07:55 AM
it should still fix some issue I create a temporary table containing the sales totals (i.e. the "popularity") for each design, then I JOIN that to the designs table:
code :
SELECT * FROM designs d
LEFT JOIN
(
    SELECT design, COUNT(*) AS popCount
    FROM sales
    WHERE paid = 1
    GROUP BY design
) s
ON d.id = s.design
WHERE d.status = 1

Can I do "SELECT COUNT(*) FROM XXX GROUP BY XXX" and "COUNT(DISTINCT XXX )" in DynamoDB?


By : soser
Date : March 29 2020, 07:55 AM
help you fix your problem 1) group my data by an attribute and count how many elements are in each group.
GROUP BY function is not supported by DynamoDB at the moment. You need to Scan or Query the table and implement it yourself.

How to construct yql for "select count(DISTINCT user_id), count(*) from music group by gender"


By : Yael Sarusi
Date : March 29 2020, 07:55 AM
hope this fix your issue The problem is that you want two different counts at the same level (documents and unique users).
This can usually be solved by unique labelling using "as", but unfortunately we require a matching each for label which doesn't account for this case. I'll create a GitHub issue for that. That said, you can achieve this by writing it as two parallel groupings with matching each'es:
code :
all(all(group(gender) each(output(count())) as(documents))
    all(group(gender) each(group(user_id) output(count())) as(users)))

DataTable.Select("Bla='Blablabla'").Count Returns 'Count' is not a member of 'System.Array' Exception


By : Sandeep
Date : March 29 2020, 07:55 AM
Does that help I'm trying to access the Count Property on the array of rows returned by the datatables select method, this is after converting the Web Project to 3.5 , Use .Length instead.
Related Posts Related Posts :
  • How to count the total amount of similar rows in a MySQL query
  • What is the right version of MySQL Workbench to connect to a mysql 5.6 db?
  • How can I query in Japanese on Rails active record?
  • Mixing variable assigment and data retrieval - MySQL vs MS SQL Server
  • MYSQL ENUM ; Invalid Syntax
  • How to make a common auto increment id for two tables
  • Best database table design for a table with dependent column values
  • Is it advisable to add additional Indices to MySQL tables when using CakePHP
  • MySQL: Populating A Table with Random Dates or Null Vallues
  • How does MySql sort data when the data of the sort filed is duplicate?
  • WHAT DOES THIS MEAN GUYS?
  • MySQL: Returning Counts (*) with NULL or 0 Vales
  • How to Know records updated with Update query?
  • Failing to get the desired results for a RIGHT JOIN
  • Mysql issue when creating a new user
  • How to use a single table for multiple users
  • Update Email Matching Between 2 Tables in MySQL - BLACKLIST
  • Is it possible to add an integer holding months to a date type in a query and output with AS to have a new column in MYS
  • MySQL index is not used when certain columns are returned
  • Group by 200 rows, start with newest ID
  • Force liquibase to current_timestamp instead of now()
  • get the sum of datas in the same date and get an array for weekly reports
  • SQL Query Group by column values, and get o/p as separate column
  • Can't change Laravel table column type
  • How to store many to many relationship with extra column data
  • Is there a way to join databases of two different data sources(ie. Mysql and Postgres SQL) using logstash and indexing i
  • how can I rearrange the ID orders?
  • Unpivot table in MySQL
  • How to save data from the serial port to the mysql database with C programming
  • Insert into *table name* select *function call* doesn't work
  • Unable to connect to MySQL database from vps using localhost
  • How to make a SQL query to select rows with dynamic interval
  • How kubernetes service work in case of Database (mysql)?
  • Laravel Eloquent - Multiple NOT LIKE queries?
  • MySQL : How to aggregate table column into a list and count?
  • a sum() function with aritmatich 4 table
  • Deleting query in a SQL query without using types
  • MYSQL Join tables with a dynamic condition CASE
  • how to cleanly stop Mysql recover process
  • Why does the MySQL query fail within this Lua script?
  • Is there a way to not show the separator in CONCAT_WS when trying to concatinate empty or NULL row's?
  • Error 1064:You have an error in your SQL syntax - mysql select query
  • I need to find out the name and customer id of customers who bought 2 cars from all the 4 dealerships
  • Total products ordered by each customer
  • MySQL. search data in serialized column
  • RMySQL - automating reading data from DB tables
  • Mysql not like and able to find a record
  • An SQL query to get the exact matching results
  • How to properly use Knex / Bookshelf with MySQL on RDS
  • MySQL get dates from a range for which the records does not exist in the database table
  • Why mysql and perl base64 string encoding is different?
  • Second SELECT query in another table if first SELECT returns 0 rows
  • Mysql instance in google cloud console (Appengine) crashed
  • [Perl]read text file with delimiter and insert into mysql table in perl 5.10
  • Join syntax on MYSQL
  • mysql - merge cols into one row
  • SQL: return true/false if multiple values exists or not in a subquery
  • SQL-how to select only doubles/date/timeStamps/time/strings values from a string column?
  • SQL limit query optimization with condition and sort
  • Can you run a raw MySQL query in Django without a model?
  • shadow
    Privacy Policy - Terms - Contact Us © 35dp-dentalpractice.co.uk