As part of referential integrity your PRIMARY KEY can refer to the PRIMARY KEY of another table and is called FOREIGN KEY.
For example in my membership data base my main table is RegisterOfMbrs with a PRIMARY KEY of MbrNumber. I have another table MbrCurHomeAdr PRIMARY KEY MbrNumber but MbrCurHomeAdr is related to RegisterOfMbrs and I define a FOREIGN KEY for MbrCurHomeAdr using the MbrNumber that references MbrNumber in RegisterOfMbrs. This insures that I always have a valid MbrNumber in my MbrCurHomeAdr record and That I cannot delete records from RegisterOFMbrs if a record still exists in MbrCurHomeAdr. Jim Bentley American Celiac Society [email protected] tel: 1-504-737-3293 ----- Original Message ---- From: Steve Breen <[email protected]> To: RBASE-L Mailing List <[email protected]> Sent: Sun, November 15, 2009 1:02:34 PM Subject: [RBASE-L] - Re: Index Designations Ok on more question What is a Primary Key Case Referenced mean or is it used for? Thanks -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Bentley Sent: Sunday, November 15, 2009 8:55 AM To: RBASE-L Mailing List Subject: [RBASE-L] - Re: Index Designations PKC = PRIMARY KEY COLUMN UIPK = UNIQUE INDEX (The unique index is probably referenced) Jim Bentley American Celiac Society [email protected] tel: 1-504-737-3293 ----- Original Message ---- From: Steve Breen <[email protected]> To: RBASE-L Mailing List <[email protected]> Sent: Sat, November 14, 2009 3:35:53 PM Subject: [RBASE-L] - Index Designations Can anyone tell me what the following designations mean when I list index PKC and UIPK Thanks for the help Stephen Breen CDI Services, Inc. 3610 Deahl Ct. P.O. Box 3838 - 46619 South Bend, IN 46628 574-532-7445 - Cell - Call this 1st if not Road Support Business 800-492-8135 Ext 207 Fax: 574-247-4631 www.911roadrepair.com <http://www.911roadrepair.com/> [email protected]
