I have two tables and data like below: I want to compare two table’s columns “Type and MatchType” and identify the Ids of first table where Type is missing in MatchType. “Type” and “MatchType” are …
Tag: join
Find IDs and names of students who took CS-101 and did not take CS-319
Can someone help with this homework problem: Find IDs and names of students who took CS-101 and did not take CS-319. These are the two tables that I can use for this assignment: I tried this but was unable to successfully exclude the students who who took “CS-319” Answer There are at least three s…
I have 3 table and need exclusive left join
Table_1: Table_2: Table_3: Using 2 left joins I got this: But I do group over the first column and 8 is accumulated twice, I wish to get: I also wish to avoid UNION ALL because my first table is actually a complex query, I wish to avoid its recalculation. https://dbfiddle.uk/?rdbms=postgres_12&fiddle=d601…
Create View based on join of column name and table value of two tables
I got two tables. and a second The resulting View I need would look like this: I only managed to get it done with one column combined with a where clause: I would probably need some command which loop through the column names and joins column names with the values in the attribute column, because the real tab…
Selecting columns from tables based on max value of another column
I have two tables and I want column input from first_table and column output from second_table based on the latest finished time first_table: second_table result_table I am trying to use this query: Answer You can use a correlated subquery in the on clause of the join: For performance here, you want an index …
Join the records with sql?
I have a table with those 5 rows. code | type_id | status —–+——–+——– 123 | 123456 | DONE 123 | 456789 | DONE 321 | 654321 | DONE 321 | 897321 | DONE 456 | 999888 | DONE 456 | …
Is there any better way to avoid data skew by join in Redshift?
The query SQL as below cause one node of Redshift cluster disk full And query plan is From the above image we know node-39 hold more data than other nodes. Because data is skewed by join. To solve this issue, we try to use update instead of join Query plan The data is distributed evenly on all nodes according…
Join three count queries and get results in to three columns
I want to combine three count queries and get results in to separate columns. This is how my data set looks like. I have tried this select id, sum(val = 3) as valcount3 from (select id, s1 as val …
MySQL SELECT 1 Parent many Children values
I have one parent with many children and I would like from the parent Id selecting value from 3 children, if it’s possible. I tried this SELECT children1.value1, children2.value2, children3.value3 …
Get room members, room’s owner and admin at the same time in one query with grouped by id (unique) on PostgreSQL 12
I want to get room’s member list, room’s owner member in case of he doesn’t exists in other table and admin member at the same time. Currently i fetch them individually. CREATE TABLE public….