Big Query 匹配表之间的记录

Question

I have two tables:

TableA

ID          Gender               BeginDate      
034446         F          2016-01-15T00:00:00
034446         F          2020-02-17T00:00:00
035689         F          2016-01-14T00:00:00
035679         F          2016-01-18T00:00:00
045687         F          2020-05-21T00:00:00

TableB

ID            Gender        Date        
34446         F          2016-01-14
35689         F          2016-01-14
35679         F          2016-01-18

I'm trying to figure out how many records(and which ones)from TableB do not match up with Table A as well as how many do. Both tables have duplicate ID's which is why I need to also use the Date field to match up records. The date field from TableB might be a day or two off between tables. For example, the first row of Table B should match with the first row of Table A, not the second row. There needs to be a statement saying TableA date field is either equal to or between a day or two from the date field of TableB. I have attempted to write a query below but have the dates set equal to eachother.

SELECT a.ID, CONCAT('0',CAST(b.ID AS STRING)), EXTRACT(DATE FROM a.BeginDate) AS date
FROM `dev.tableA` a
LEFT OUTER JOIN `dev.TableB` b
ON a.ID = CONCAT('0',CAST(b.ID AS STRING))
AND EXTRACT(DATE FROM a.BeginDate) = b.Date

Answer 1

If I follow you correctly, you can use exists :

select b.*
from tableb b
where not exists (
    select 1
    from tablea a 
    where a.id = b.id
        and a.begindate >= date_sub(b.date, interval 2 day)
        and a.begindate <= date_add(b.date, interval 2 day)
)

This brings records of b for which no match exists in a with the same id and a date that falls within +/- two days. You can add the casting on id , if that's really necessary, and adjust the boundaries as needed.

If you want an overall record count, you can just replace b.* with count(*) .