Tagged Questions
1
vote
1answer
44 views
Correct data model for users with clients
I have an application where users are granted access. Part of the system allows users to have their own 'clients'.
I have a users table
********************************
users
...
5
votes
2answers
107 views
Resolving DUPLICATE for a column with UNIQUE
I have a few column with UNIQUE INDEX. In some queries, duplicates should be acceptable, in which a postfix should be added to the value. For example, if test title exits, we change it to test ...
1
vote
1answer
1k views
How to use ON DUPLICATE KEY for UPDATE
Consider a table of
CREATE TABLE test
(
id int(11) unsigned NOT NULL AUTO_INCREMENT,
external_id int(11),
number smallint(5),
value varchar(255),
UNIQUE INDEX (external_id, number),
PRIMARY KEY(id)
...
2
votes
4answers
605 views
Two-sided UNIQUE INDEX for two columns
Creating a table with composite PRIMARY KEY or using UNIQUE INDEX for two columns guarantee uniqueness of col1, col2. Is there a tricky approach to make the reverse order of two columns UNIQUE too ...
9
votes
3answers
4k views
PostgreSQL multi-column unique constraint and NULL values
I have a table like the following:
create table my_table (
id int8 not null,
id_A int8 not null,
id_B int8 not null,
id_C int8 null,
constraint pk_my_table primary key (id),
constraint ...
