Обсуждение: weird(to me) request
I have the following rows (in addition to others): acct_num text, master_acct_num text, These are in the same table. What I want to enforce is that if the master_acct_num field is NOT NULL (it can be NULL, and that's fine), that the value appears in some row as acct_num. acct_num has a unique index on it, so that's fine. I'm not sure how to do this.... Thanks! LER -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
Użytkownik Larry Rosenman napisał: > I have the following rows (in addition to others): > > acct_num text, > master_acct_num text, > > > These are in the same table. > > What I want to enforce is that if the master_acct_num field is NOT > NULL (it can be NULL, and > that's fine), that the value appears in some row as acct_num. > acct_num has a unique index on it, so that's fine. > > I'm not sure how to do this.... > > Thanks! > > LER > > select case when master_acct_num is null then acct_num else master_acct_num end from table; did you mained somethink like this ?
--On Thursday, September 25, 2003 20:59:25 +0200 Adam Wieckowski <adam-wieckowski@tlen.pl> wrote: > U¿ytkownik Larry Rosenman napisa³: > >> I have the following rows (in addition to others): >> >> acct_num text, >> master_acct_num text, >> >> >> These are in the same table. >> >> What I want to enforce is that if the master_acct_num field is NOT >> NULL (it can be NULL, and >> that's fine), that the value appears in some row as acct_num. >> acct_num has a unique index on it, so that's fine. >> >> I'm not sure how to do this.... >> >> Thanks! >> >> LER >> >> > select > case > when master_acct_num is null > then acct_num > else master_acct_num > end > from table; > > did you mained somethink like this ? I'm actually looking to enforce the fact that if master_acct_num is entered, it points to a valid acct_num. LER -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
On Thursday 25 September 2003 19:51, Larry Rosenman wrote: > I have the following rows (in addition to others): > > acct_num text, > master_acct_num text, > > > These are in the same table. > > What I want to enforce is that if the master_acct_num field is NOT NULL (it > can be NULL, and > that's fine), that the value appears in some row as acct_num. acct_num has > a unique index on it, so that's fine. > > I'm not sure how to do this.... ALTER TABLE my_table ADD CONSTRAINT my_self_fk FOREIGN KEY (master_acct_num) REFERENCES my_table (acct_num); It's really just a foreign-key to yourself -- Richard Huxton Archonet Ltd
--On Thursday, September 25, 2003 20:09:35 +0100 Richard Huxton <dev@archonet.com> wrote: > On Thursday 25 September 2003 19:51, Larry Rosenman wrote: >> I have the following rows (in addition to others): >> >> acct_num text, >> master_acct_num text, >> >> >> These are in the same table. >> >> What I want to enforce is that if the master_acct_num field is NOT NULL >> (it can be NULL, and >> that's fine), that the value appears in some row as acct_num. acct_num >> has a unique index on it, so that's fine. >> >> I'm not sure how to do this.... > > ALTER TABLE my_table ADD CONSTRAINT my_self_fk FOREIGN KEY > (master_acct_num) REFERENCES my_table (acct_num); > > It's really just a foreign-key to yourself I wasn't sure I could do that. Thanks! LER -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749