Re: Non-standard escape sequences from Crystal Reports
От | Rajesh Kumar Mallah |
---|---|
Тема | Re: Non-standard escape sequences from Crystal Reports |
Дата | |
Msg-id | AANLkTikOgJ2zCEZotYmTQ6RhzrkuqayCiS7L9N7Dp6_N@mail.gmail.com обсуждение исходный текст |
Ответ на | Non-standard escape sequences from Crystal Reports ("Rob Richardson" <Rob.Richardson@rad-con.com>) |
Список | pgsql-general |
Dear Rob, Please do not go offlist. Its not a matter of cancelling, consider the fragment --> relname like 'coil\\_status' the underscore has to be escaped because if its not done '_' will match any *single* character (rule of ilike matching) , its escaped so that it matches '_' in strings. two backslash is required so that ilike gets \_ it is the rule of quoting literal values in sql. if you can add E you can get rid of the warnings. Regds Rajesh Kumar Mallah. On Tue, Oct 5, 2010 at 2:18 PM, Rob Richardson <Rob.Richardson@rad-con.com> wrote: > Thank you very much! Your examples worked as you said they would work, and > they showed that my database is logging those warnings when they happen. > That indicates that the difference is in the Crystal Reports installation > someplace. > > I don't understand how the backslashes are handled. I added underscores to > a couple of records in my coilstatus table, so one had "Fr_ee" and another > had "Pack_ed". Then, the query "SELECT status from coilstatus where status > like '%\\_%' limit 10;" gave me the warning that you predicted, and it found > the two records with underscored statuses. That tells me that the two > backslashes cancelled each other out, and the query was the same as "SELECT > status from coilstatus where status like '%_%' limit 10;". Why is that? > Do I need to read about regular expressions? > > RobR > >
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