Line Comment

[WILLIEWANKA]

I'm running into unexpected results when I use a line comment at the end of a line

sel trim('a') || trim('     ') || trim('b') || '    ' || substr('0000000000', 1,4)

Will give me expected results, but

sel trim('a') || trim('     ') || trim('b') || '    ' || substr('0000000000', 1,4)  --'98.3';

Will do some funky things. Why does a line comment at the end of a line not do what it should do? The manual says teradata should know that anything after "--" is conisdered a null statement.

 

[yksvaan]

I've noticed this too.

If the expression on the left of -- can be implicitily converted as a number, or is a number (see below), TD might interpret -- as "minus unaryminus expression", which is of course same as plus.

SELECT 8+12 --4

This problem can be avoided by having always an extra hyphen, with numbers too, like this

sel trim('a') || trim('     ') || trim('b') || '    ' || substr('0000000000', 1,4)  --' '98.3'

sel trim('a') || trim('     ') || trim('b') || '    ' || substr('0000000000', 1,4)  --' 98.3

So, using --' as the comment token should work.

Cheers

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