Add escapes for dates and datetimes for MS Access #609
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Can you please add a bullet to the top of NEWS.md? It should briefly describe the change and end with (@yourname, #issuenumber).
R/backend-access.R
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| sql_escape_datetime.ACCESS <- function(con, x) { | ||
| # Access delimits datetimes using octothorpes, and uses YYYY-MM-DD HH:MM:SS | ||
| # Timezones are not supported in Access | ||
| y <- format(x, "#%F %T#") |
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What does not supporting time zones imply here? Should we always generate a time in the system time zone?
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It means timezone information is ignored when you escape a value that includes timezone information, e.g. escape(as.POSIXct('2020-01-01 01:01:01', tz = "US/Alaska"), con = simulate_access()) will result in the same thing as escape(as.POSIXct('2020-01-01 01:01:01', tz = "Europe/Berlin"), con = simulate_access()).
Some RDBMSes have a concept of timezones (e.g. SQL Server, Oracle) and when escaping a datetime field the timezone could be included, however, Access does not.
I assume that's a non-issue, especially since escapes for those databases (e.g. escape(as.POSIXct('2020-01-01 01:01:01', tz = 'US/Alaska'), con = simulate_mssql())) always provides the zulu timezone and also ignore timezone information. But that's a separate issue, and one that's considerably harder to address and might break existing code when addressed.
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Ah, got it. Thanks for the explanation!
hadley
changed the title
Per preference of Hadley Wickham, adjusted the format strings to more explicitly write out the format
Closes #608