Hi Mr. George, Sorry for confusing u so much... Let me try it again... I am not using any relational database to store the required tables with primary keys & foreign keys....
When I say PRIMARY KEY => 1. It means an index is created on the specified fields (Out of various fields given in the comma separated txt file) FileFormat: CODE, FIRST_NAME, last_name, area_of_expertise, country Eg: A1,Harry,George, python, XYZCOUNTRY--------(1st record) 2. The index can be formed on a single field or on multiple fields Eg: a. 'CODE' (single field ) {pk_code} b. 'CODE' & 'NAME' (multiple fields ) {pk_code_fname} Now when I say FOREIGN KEY => 1. If the foreign Key is formed on the field 'CODE' in another text file Format: subsriber_code,CODE,first_name, no_of_posts,active(Y/N) Eg: SUB_001, A1, Harry, 50, Y This means the CODE (A1) given here is checked in the index formed above with primary key: pk_code... 2. If the foreign Key is formed on the fields 'CODE' & 'FIRST_NAME' Format: subsriber_code,CODE,FIRST_NAME, no_of_posts,active(Y/N) Eg: SUB_001, A1, Harry, 50, Y This means the CODE (A1) & FIRST_NAME (Harry) given here are checked in the index formed above with primary key: pk_code_fname... I am done till here..... The problem starts if I have defined an index on multiple fields (composite PK) say: CODE & FIRST_NAME (pk_code_fname) and if I need to define a FK on a single field out of these say: CODE I am unable to do that... Mr. George, I thought i must explain the code i am dealin with, for better understanding.., but i am sorry i confused you all the more (incase, u want to view the code please refer to the code snippets in my first query posted) Thanks & regards, sonal -- http://mail.python.org/mailman/listinfo/python-list