Questions tagged [gaps-and-islands]

Gaps and islands problems involve finding a range of missing values (gaps) or a range of consecutive values (islands) in a sequence of numbers or dates.

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How to perform a running count on null values that resets on non-null values

I am trying to calculate a column that performs a running count of consecutive null values, but the running count will reset upon non-null values. Currently I am trying to do it with a window function ...
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How to use windowing functions to find gaps in sequences grouped by a column, in PostgreSQL

I have a table structure which has 2 columns: client_id, order_no, and both are integers. I'd like to find gaps in order_no in the data so that, for example, for a table containing these rows: 42, 1 ...
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Finding the largest island size (redshift)

Current sql code will sum up all the max island sizes into one. I'm trying to only find what the max island size is. select deviceid, grp -- min(readdate) as mn, max(readdate) as mx from ( ...
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295 views

Count of range on datetime in MySql

I want to group table entries for each userId only if they are consecutive entries in the table. I have a table like this. id userId transactionTime 1 1 2016-04-13 22:15:44 2 1 ...
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How to collapse contiguous single day start/end date ranges in MySQL

(edited - I oversimplified the original problem) I'm trying to figure out a MySQL query that will collapse one-day long contiguous start/end date ranges. Here is my sample input data: INSERT INTO ...
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Gaps and Islands Across Fields With Start and End Timestamps

I am working with GPS data which I want to group by locations (to six decimal places of the coordinate value) and generate from and until times for. For simplicity in this example I'm making the ...
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2answers
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Mysql consecutive days user wise

Table 'present' +--------+------------+ | emp_id | pre_date | +-----------+---------+ | 002 | 2019-04-01 | | 001 | 2019-04-21 | | 001 | 2019-04-15 | | 001 | 2019-04-19 | | 002 | 2019-...
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how to counting time in partition (MYSQL)

I looking for how to counting time by partition in condition if value=1 occurs consecutively 3 or more times count 1 activity. Showing result on this picture
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Find consecutive entries in a table and group into another table

So ideally I'd like a table output such as: consecutive_days | max_date for a given user where consecutive days is the number of days a person logged something and max_date was the last date in ...