group-by

问题 Trying to group tow columns and and populate it as a particular series on highcharts. my code not grouping columns, And showing all data as a single series. $query = $db->Prepare("SELECT class, SUM(marks), DATE(date_column) as dates FROM classes GROUP BY class,DATE(date_column)"); $query->execute(); while ( $row = $query->fetch(PDO:: FETCH_ASSOC)) { $date = $row['dates']; $dates[] = $row['dates']; $class[] = $row['class']; $marks[] = $row['SUM(marks)']; $output[] = array($date,(int)$marks); }

问题 EDIT: I will leave the post here as is, but what I really needed to accomplish needed to be reposted. I didn't explain the problem well enough. After trying again with quite a different starting point, I was able to get the query that I needed. That is explained here. ORIGINAL QUESTION: I'm having trouble. I have looked at similar threads, and I am unable to find a solution specific to this query. The database is very large, and group by seems to slow it down immensely. The problem is I am

问题 I have a 3 part problem thats been giving me trouble I know how to get the tables to work if I query 1 table at a time but I can't seem to figure out how I can combine both the tags and more_tags tables to get the same results. The 3 main problems I have are Listed below. PROBLEM 1 I want to be able to group the same tag from both the tags and more_tags tables. PROBLEM 2 I also want to be able to display the tags from each table that are not present in the other table. PROBLEM 3 I also want

问题 I have the following table recordID createdDate ForeignKeyID 00QA000000PtFXaMAN 2012-01-03 13:23:36.000 001A000000ngM21IAE 00QA000000OS2QiMAL 2011-12-15 12:03:02.000 001A000000ngM21IAE . . . . I am trying to get the recordID for foreignKeyID where createdDAte is the min(createdDate) for foreignKeyID if recordID is identity int I can get that by doing the following query Select min(recordId),ForeignkeyID from table group by ForeignKeyId I originaly thought that I can create temp table with the

问题 I would like to achieve SELECT @param1, @param2, @param3, t.field1, sum(t.amount) FROM table t WHERE t.field 2 IS NOT NULL AND t.field3ID = '12345' GROUP BY @param1, @param2, @param3 What is the best approach? Is building dynamic SQL is the way to go? 回答1: Dynamic SQL is the only way to go here. However, what kind of table do you have where you have a bunch of optional grouping columns? 回答2: First of all t.field1 should also be in your group by or handled in the sql with an aggrigate function

问题 I'm curently learnig python and pandas (this question is based on a pevious post but with an additional query); at the moment have the 2 columns containing numeric sequences (ascending and/or descending) as described below: Col 1: (col1 numeric incrememt and/or decrement = 1) 1 2 3 5 7 8 9 Col 2: (Col2 numeric increment and/or decrement = 4) 113 109 105 90 94 98 102 Need to extract the numeric ranges from both columns and print them according to the sequence break occurance on any of those 2

问题 In MySQL, I would like to have an extra column showing the sum of values of a particular column. However, the numbers I would like to sum come from a subquery and are not stored in a separate table, something like this: (SELECT a.ID, MAX(a.COUNT_ID) AS MAX_COUNT FROM (SELECT ID, COUNT(*) AS COUNT_ID FROM my_table GROUP BY COL1, COL2) a GROUP BY COL1, COL2) b And this would output something like: ID MAX_COUNT ABC 1 DEF 2 GHI 3 And now, I want an extra column showing the sum of MAX_COUNT, like

问题 Performing a WITH ROLLUP when grouping by multiple fields, MySQL returns a rollup row for each group, as well as the overall summary: CREATE TABLE test (name VARCHAR(50), number TINYINT); INSERT INTO test VALUES ('foo', 1), ('foo', 1), ('foo', 2), ('foo', 3), ('foo', 3), ('bar', 1), ('bar', 2), ('bar', 2), ('bar', 2), ('bar', 3), ('baz', 1), ('baz', 2), ('bar', 2); SELECT name, number, COUNT(1) FROM test GROUP BY name, number WITH ROLLUP; +------+--------+----------+ | name | number | count(1

问题 I have a MySQL table where I store results from a racing championship, so that every rows contains -among other data- every driver's position in a certain race. I want to get the sum of a certain driver's top 5 placings (for instance, if a driver's best positions were 1,2,2,4,5, I'd like MySQL to return 14). What I'm trying to do is this: SELECT driver, SUM(position) FROM results WHERE (race, season, position) IN (SELECT race, season, position FROM results WHERE driver = "Vettel" ORDER BY

问题 SQL : Select Max(A) , Min (B) , C from Table group by C I want to do the same operation in pandas on a dataframe. The closer I got was till : DF2= DF1.groupby(by=['C']).max() where I land up getting max of both the columns , how do i do more than one operation while grouping by. 回答1: try agg() function: import numpy as np import pandas as pd df = pd.DataFrame(np.random.randint(0,5,size=(20, 3)), columns=list('ABC')) print(df) print(df.groupby('C').agg({'A': max, 'B':min})) Output: A B C 0 2 3