0
173
VisualizaçõesComparing Dates by Fixed Level of Detail in mySQL
Good Morning,
I'm trying to create a mySQL query with the following output:
In order to get the 60_days_since_seen, I need to compare the reference_date for the current row to the next most recent reference_date relative to the unique_identifier and determine if that reference_date is older than 60 days from the reference_date from that row.
Ex: unique_identifier = 123456789
id = 1: Since there is no date before this instance, the 60_days_since_seen is TRUE (or 1).
id = 2: Since the date of the reference_date occurrence prior to this id relative to the unique_identifier is less than 60 days since this row's reference_date, the 60_days_since_seen is FALSE (or 0).
id = 3: Since the date of the reference_date occurrence prior to this id relative to the unique_identifier is greater than 60 days since this row's reference_date, the 60_days_since_seen is TRUE (or 1).
id = 4: Since there is no date before this instance, the 60_days_since_seen is TRUE (or 1).
id = 5: Since the date of the reference_date occurrence prior to this id relative to the unique_identifier is less than 60 days since this row's reference_date, the 60_days_since_seen is FALSE (or 0).
1 Respostas
Responde à pergunta0
The first query works also with mysql 5.x.
The second uses window functions that are only supported in mysql 8
CREATE TABLE datetable ( `Id` INTEGER, `unique_identifier` INTEGER, `reference_date` Date ); INSERT INTO datetable (`Id`, `unique_identifier`, `reference_date`) VALUES ('1', '123456789', '2020-01-05'), ('2', '123456789', '2020-02-20'), ('3', '123456789', '2020-06-29'), ('4', '987654321', '2020-02-21'), ('5', '987654321', '2020-03-30');
SELECT `Id`, `reference_date` ,IF(@unique_identifier = `unique_identifier`,IF(DATEDIFF(`reference_date`,@date) > 60,1,0),1) 60_days_since_seen ,@unique_identifier := `unique_identifier` as 'unique_identifier' ,@date :=`reference_date` 'reference_date' FROM (SELECT * FROM datetable ORDER BY unique_identifier,reference_date) t1 ,(SELECT @unique_identifier := 0) a,(SELECT @date := NOW()) bId | reference_date | 60_days_since_seen | unique_identifier | reference_date -: | :------------- | -----------------: | ----------------: | :------------- 1 | 2020-01-05 | 1 | 123456789 | 2020-01-05 2 | 2020-02-20 | 0 | 123456789 | 2020-02-20 3 | 2020-06-29 | 1 | 123456789 | 2020-06-29 4 | 2020-02-21 | 1 | 987654321 | 2020-02-21 5 | 2020-03-30 | 0 | 987654321 | 2020-03-30
SELECT `Id`, `unique_identifier`, `reference_date`, IF(DATEDIFF(reference_date , LAG(reference_date) OVER ( PARTITION BY unique_identifier ORDER BY reference_date ))> 60 OR LAG(reference_date) OVER ( PARTITION BY unique_identifier ORDER BY reference_date ) is NULL,1,0) 60_days_since_seen FROM datetableId | unique_identifier | reference_date | 60_days_since_seen -: | ----------------: | :------------- | -----------------: 1 | 123456789 | 2020-01-05 | 1 2 | 123456789 | 2020-02-20 | 0 3 | 123456789 | 2020-06-29 | 1 4 | 987654321 | 2020-02-21 | 1 5 | 987654321 | 2020-03-30 | 0
db<>fiddle here