group-by

问题 I have weird problem with mysql and GROUP BY queries. See below: mysqlslap --concurrency=5 --iterations=1 --query=/root/test.sql --create- schema=testd -u root -p Benchmark Average number of seconds to run all queries: 2.575 seconds Minimum number of seconds to run all queries: 2.575 seconds Maximum number of seconds to run all queries: 2.575 seconds Number of clients running queries: 5 Average number of queries per client: 1 But when I'm running just 1 query it will look like this: mysqlslap

问题 I am trying to perform a group by followed by a distinct to verify if a set of columns maps to only other column. For example, in the dataset below Brand Product Location Customer Demand Box A Chicago Chicago 10 Box B Chicago Milwaukee 20 Cart C Madison Milwaukee 10 Cart D Chicago Milwaukee 15 Product A, B, C are valid. But D is not valid since there exists a Product B with Chicago as Location & Milwaukee as Customer. I am trying to build a LINQ query to get the exception record and having

问题 How do i identify the first row that has value for each Brand and Category, then update Column "FirstValue" as 1, else 0? e.g of expected table Date | Brands | Category | Value | FirstValue Jan 08 | A | 1 | 0 |0 Jan 08 | A | 2 | 0 |0 Jan 08 | A | 3 | 0 |0 Jan 08 | B | 1 | 12 |1 Jan 08 | B | 2 | 0 |0 Jan 08 | B | 3 | 0 |0 Feb 08 | A | 1 | 5 |1 Feb 08 | A | 2 | 0 |0 Feb 08 | A | 3 | 67 |1 Feb 08 | B | 1 | 0 |0 Feb 08 | B | 2 | 0 |0 Feb 08 | B | 3 | 6 |1 回答1: Common table expressions are

问题 I checked the following questions: GROUP BY with MAX(DATE) Fetch the row which has the Max value for a column Columns : account_number, app_guid, time_event_published(epoch time). I want the latest row of each app_guid for a given account_number PLUS oldest time_event_published of the same account_number for each app_guid in another column of the latest row. SELECT id, account_number, app_guid, time_event_published , <oldest_time_event_published_for_2152331553409959696> FROM ( SELECT id,

问题 I'm new to Angular and would like to learn the best way to handle a problem. I want to access keys in my first ng-repeat grouped by multiple columns. <table width="100%" style="text-align: center;" data-role="table" data-mode="" class="ui-responsive ui-shadow"> <thead> <tr> <th>Id</th> <th>Course</th> <th>Module</th> <th>Subject</th> <th>Toc</th> <th>Chapter</th> <th>Activity Done</th> <th>Start</th> <th>End</th> <th>Time Spent</th> </tr> </thead> <tbody ng-repeat="(key, value) in sessions |

问题 I've got this SQL query: SELECT oy.ownerId, oy.Year, COUNT(doc.Id) as docCount FROM aavabruf.owneryears oy left join vastdocuments doc on oy.ownerId = doc.Ownerid and oy.Year = doc.Year group by oy.ownerid, oy.year order by docCount It shows docCount as ZERO for the OwnerId, Year pairs that have no document match in the vastdocuments table. I tried to do the same with LINQ using the suggested left outer join solution: from oy in OwnerYears join doc in VaStDocuments on new {oy.OwnerId, oy.Year

问题 This question already has an answer here : Get a substring from a column and perform a groupBy and count (1 answer) Closed 3 years ago . I need to get a substring from a column 'source' from typeTable and be able to get stats on each region from that one column. A row would look something like 'server001[en-US]'. Then print the stats for each country. That is, I need the countForType and totalForType for each country. So, I believe get all server001 calls and group them by country is what I'm

问题 I have a table of products with their owners. Each owner is in their own row and has an owner type of either primary or secondary. Not every product has a secondary owner. I need to get a table grouped by product with the primary owner in one column and all the secondary owners concatenated in a second column. If a product has multiple primary owners it should select the first one and the rest go to the secondary owners. If a product doesn't have a primary owner then it should just select the

问题 I have this dataframe: df1: drug_id illness lexapro.1 HD lexapro.1 MS lexapro.2 HDED lexapro.2 MS lexapro.2 MS lexapro.3 CD lexapro.3 Sweat lexapro.4 HD lexapro.5 WD lexapro.5 FN I am going to first group the data based on drug_id, and search for availability of HD, MS, and FN in the illness column. Then fill in the second data frame like this: df2: drug_id HD MS FN lexapro.1 1 1 0 lexapro.2 0 1 0 lexapro.3 0 0 0 lexapro.4 1 0 0 lexapro.5 0 0 1 This is my code for grouping. df1.groupby('drug

问题 I have this class: public class Item { public virtual int32 Id { get; set; } public virtual Previa Previa { get; set; } public virtual Product Product { get; set; } public virtual Int32 Quantity { get; set; } public virtual Decimal Price { get; set; } public virtual Decimal Total { get; set; } } And now i need to a query to find every Items in database, group by Products, with the sum of Quantity and Total. For find every Items, i use: public List<Item> FindItem(int IdProduct = 0) { var