Tag: unique-constraint

Found 130 results for 'unique-constraint'.

1) mysql - Should I create a multi-column UNIQUE index?
2) mysql - How to prevent duplicate VARCHAR without a key limit?
3) oracle - Can an Oracle IDENTITY column be nullable?
4) postgresql - Email address unique or primary key?
5) postgresql - Remove extra email characters to enforce uniqueness
6) mysql - Unique constraint on 3 different columns but a specific value in 3rd column allows duplicate row entries
7) index - How to index "almost" unique columns?
8) postgresql - PostgreSQL multi-column unique constraint and NULL values
9) postgresql - Postgres - Only allow insert if TWO columns match with a separate table
10) mysql - How can I do 'insert if not exists' in MySQL?
11) postgresql - Is it reasonable to mark all columns but one as primary key?
12) database-design - When to use unique composite keys?
13) postgresql - Does creating a unique constraint on a Postgres column remove the need to index it?
14) sql-server - Handling duplicate values using trigger
15) mysql - Why does InnoDB allow a 772 byte unique constraint?
16) mariadb - Making a field greater than the limit unique
17) postgresql - PostgreSQL UPSERT issue with NULL values
18) postgresql - Why do composite foreign keys need a separate unique constraint?
19) postgresql - How to enforce a column value on duplicate values on postgresql using constraint?
20) postgresql - Duplicate key violates unique constraint
21) mysql - Increment value for unique key column
22) primary-key - Relationship with a table without unique/primary key
23) mysql - Differences between "Unique Key" and "Primary Key"
24) ms-access - How can I allow part of a key to be null and enforce uniqueness of records with nulls?
25) sql-server - N'Șc' considered duplicate key of N'C' using Latin1_General_CI_AS collation
26) database-design - Enforce uniqueness across optional attributes for an entity
27) postgresql - postgresql Modifying existing unique index
28) primary-key - Does a primary key contain exactly one Null value...?
29) postgresql - Make a boolean column unique per group
30) postgresql - PostgreSQL duplicate key violates unique constraint error
31) postgresql - Unique constraint on different columns
32) mysql - The possibility to define a composite unique constraint for specific cases
33) database-design - Correct data model for users with clients
34) sql-server - SQL Server 2014 Concurrent input issue
35) replication - Percona MySQL 5.6 databases ignoring key length at constrait creation
36) postgresql - Custom unique constraint, only enforced if one column has a specific value
37) postgresql - Creating a UNIQUE constraint from a JSON object
38) postgresql - PostgreSQL relative update breaks unique constraint
39) sql-server - When possible, are clustered indexes that are declared as unique more performant than clustered indexes that aren't declared as unique?
40) postgresql - Foreign Key NULL vs Foreign Key to an empty string
41) postgresql - Unexpected unique constraint violation during update
42) postgresql - Optimal way to ignore duplicate inserts?
43) mysql - mysql - unique index with nulls - actual solution anyone?
44) django - IntegrityError duplicate key value violates unique constraint - django/postgres
45) postgresql - Constraint to prevent immediate loop in hierarchy
46) sql-server-2008-r2 - UNIQUE index key violation
47) sql-server - Programmatically finding minimum set of fields necessary to create a unique composite key
48) postgresql - Managing CTE execution order under uncertainty
49) mysql - set unique key checks 0 in mydql
50) sql-server - SQL Insert multiple values with UNIQUE constraint