create variable timefrom time; create variable timeto time; create variable shiftdate date; create variable shiftend datetime;
gives the error "Cannot convert time to a numeric"
wrapping the if expression in a date() function solves the problem, suggesting that the if expression is returning a numeric representation of the date rather than a date datetype.
same behaviour in v184.108.40.2068 & 10.0.1
asked 30 Jul '15, 08:33
The reason seems to be that the engine fails to calculate the result type of the addition of a time to a datetime, cf. that exprtype:
It returns the same error.
In contrast, the addition of a date and a time returns a timestamp/datetime, as expected:
Additionally, the following doubled time portion addition fails, as well:
However, the engine seems to be able to calculate the addition itself, as the SET statement apparently works
The 12.0.1 docs seem to explain that behaviour here - and do not list "timestamp + time":
The following arithmetic operators are allowed on dates: timestamp + integer Add the specified number of days to a date or timestamp. timestamp - integer Subtract the specified number of days from a date or timestamp. date - date Compute the number of days between two dates or timestamps. date + time Create a timestamp combining the given date and time.
Given the Watcom date + time addition rule, I'd think the solution is as following:
As dateadd() returns a datetime but you know that adding a day to a date will still be a date, you could cast the dateadd result explicitly to a date: