how does pl/sql handle <,>, = operations on strings 2

[FatalExceptionError]

i need to know how a a compiler handles logical operations like this specifically for strings. Does it do it based on the ascii value or what.
ie if i have a statement like this

if some_string >= some_constant_string

with some_string = '20020411'
and some_constant_string = '20020101'
what would it return

 

[sem]

I suppose you're trying to compare 2 dates represented as strings. As for numbers Oracle uses ascii codes so '20020411'>'20020101' because '4' is obviously greater than '1'. As for other characters you may use ALTER SESSION to change NLS_SORT parameter to perform either binary or lexical comparison.

If my asumption regarding dates is correct I would recommend you to compare dates by using to_date function.

 

[Bimalaggarwal]

The ordering is based on the ASCII value of the characters.

'20020411' >= '20020101' => TRUE

The comparison takes place from left to right.
Since 4 has (in '200204..') higher ascii value than 1 (in '200201..') , the above expr. returns TRUE.