I have a table with columns id,time,value STEP1: get the time value from the recent row i.e SELECT time FROM tablename ORDER BY id desc LIMIT 1 STEP2: get all the rows who are within last 5 minutes from this time. How can i do this Answer One method is a subquery: If this is really not the most recent
trying to sum a column in postgres but trying to limit the results first?
I am trying to get data for the last 5 years within my database, then sum the results. Here’s what I’ve been trying: but I’m getting this error: when I comment out order by year desc, then the query works but I need it to start at the most recent year. also the limit doesn’t seem to do…
Ambiguous Source ID
I’m not sure what I’m doing wrong here. I tried to make an alias because it exits as an item in both tables I’m trying to join, but I keep getting an ambiguous error for sourceId. Answer try this change the alias for select depending on which table it is in Also are you purposely joining on …
How to Aggregate 15 minute Time series into 1 hour intervals in Postgres
In my PostgreSQL database I have a very large (over 40 mil) row table that represents traffic counts for various locations by 15 minute interval timestamps (contained in the “starttime” column). I want to bin these intervals into hourly intervals to reduce the number of rows. The format is “…
How to get increment number when there are any change in a column in Bigquery?
I have data date, id, and flag on this table. How I can get the value column where this column is incremental number and reset from 1 when there are any change in flag column? Answer Consider below approach if applied to sample data in your question – output is
Exclude all from attributes where employee table does not have connection with in the pivot table
I need to exclude all attributes that have no connection with employee1 in Pivot table. in this case attribute3. What is the SQL query for that? Answer Use not exists:
Constraint on size of array type in Postgres
I have the following schema for a table (simplified for the sake of discussion) : A task transitions from NOT_SOLVED TO SOLVED when array_length(current_solved_by) == max_solved_by Questions: Is it a good practice to maintain another column, in this case state, which can be derived from other data (Based on s…
Divide the results of two select queries
I have two SQL count queries that on their own work fine, they are: Now how to do I add to the query to get the percentage of 26/130?? I have a new query to go along with how to get percentages. Here it is: this brings back results below: If I remove the Distinct from my query there are
Extract year from timestamp in hive
I am writing the query to show the data entries for a specific year. Date is stored in dd/mm/yyyy hh:mm:ss.(Date TIMESTAMP – e.g. 12/2/2014 0:00:00). I am trying to display the two columns(name, orderdate) filtered by a specific year(year from orderdate). The requirement is to enter the specific year(20…
How to condense returned rows of users with multiple roles
I’m trying to wrap my head around this logic, but simply having a tough time. While trying to keep the database normalized, users can have multiple roles (example shows 2, but could have more than 2, currently have 6 total roles), and I’d like to return data to make it easily viewed on a front end UI. Tables …