unique-index

I have a registration form in which users can fill in two email address (email1 & email2). Marketing's requirement is that they need to be unique (unique as in if we had 10 users, then there would be 10*2=20 unique email address). The system is already built on cakephp, so what I'd like to know is, is there something similar to the isUnique feature (unique in one field) that can do this right out of the box? Or am I doomed to code this myself? Thanks in advance. EDIT: built on Richard's example, this worked for me: function checkUnique($data, $fields) { if (!is_array($fields)) { $fields =

I inserted between two tables fields A,B,C,D, believing I had created a Unique Index on A,B,C,D to prevent duplicates. However I somehow simply made a normal index on those. So duplicates got inserted. It is 20 million record table. If I change my existing index from normal to unique or simply a add a new unique index for A,B,C,D will the duplicates be removed or will adding fail since unique records exist? I'd test it yet it is 30 mil records and I neither wish to mess the table up or duplicate it. Paul Spiegel If you have duplicates in your table and you use ALTER TABLE mytable ADD UNIQUE

I want to create a unique id but uniqid() is giving something like '492607b0ee414' . What i would like is something similar to what tinyurl gives: '64k8ra' . The shorter, the better. The only requirements are that it should not have an obvious order and that it should look prettier than a seemingly random sequence of numbers. Letters are preferred over numbers and ideally it would not be mixed case. As the number of entries will not be that many (up to 10000 or so) the risk of collision isn't a huge factor. Any suggestions appreciated. lpfavreau Make a small function that returns random

I've seen a number of variations on this but nothing quite matches what I'm trying to accomplish. I have a table, TableA , which contain the answers given by users to configurable questionnaires. The columns are member_id, quiz_num, question_num, answer_num . Somehow a few members got their answers submitted twice. So I need to remove the duplicated records, but make sure that one row is left behind. There is no primary column so there could be two or three rows all with the exact same data. Is there a query to remove all the duplicates? Saharsh Shah Add Unique Index on your table: ALTER

I've been trying to sort out the relationship between unique and index in Postgres after reading the docs on index uniqueness being an implementation detail : The preferred way to add a unique constraint to a table is ALTER TABLE ... ADD CONSTRAINT. The use of indexes to enforce unique constraints could be considered an implementation detail that should not be accessed directly. One should, however, be aware that there's no need to manually create indexes on unique columns; doing so would just duplicate the automatically-created index. So taking the docs at their word I'm going to just declare