A declarative mechanism such as a check or foreign key that enforces some data integrity rule in a database.

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3
votes
1answer
116 views

Multi-tenant database constraints

I have a multi-tenant app in PostgreSQL that has a repeated tenant_id column in each table to help isolate the tenants from each other. My question is, is there any sort of way that I can use ...
4
votes
2answers
535 views

Foreign Keys doesn't work as I expect

Here are my tables; CREATE TABLE `borclular` ( `id` int(11) NOT NULL AUTO_INCREMENT, `tc` char(11) COLLATE utf8_turkish_ci NOT NULL, `borclu` varchar(255) COLLATE utf8_turkish_ci NOT NULL, ...
2
votes
4answers
124 views

ERROR: check constraint is violated by some row

I've got the following error: ERROR: check constraint "cc_at_least_one_mapping_needed" is violated by some row Query: ALTER TABLE integrations.tax_aggregates DROP COLUMN IF EXISTS myob_id, ADD ...
0
votes
0answers
34 views

database constraint using trigger [closed]

I have modified my question as follows. I have created 3 tables as follows. create table s ( sno char(5), sname varchar(25), status int, city varchar(25), primary key(sno)); create table p ...
4
votes
3answers
11k views

Listing indexes and constraints

I am looking at a SQL Server database for an application I have inherited. I have not looked into SQL Server for approximately 10 years, so please bear with me. The database table I am looking at has ...
5
votes
2answers
341 views

CREATE as SELECT with CONSTRAINT?

I have a piece of SQL that creates a TABLE form a SELECT statement in PostgreSQL ; I want to add constraints to the table so that for example a column cannot be null. I cannot find valid SQL for this ...
1
vote
0answers
29 views

How do I disable constraint checking during schema migration?

How do I disable FOREIGN KEY checking for the time of database schema migration? Currently I found engine-based commands like: PostgreSQL: SET CONSTRAINTS ALL DEFERRED; MSSQL: EXEC ...
4
votes
1answer
26 views

Enforcing that a user should have one or more email addresses

I'm trying to design an application where a user can authenticate oneself with one password and one or more email addresses. I'm not sure how to enforce this constraint. The tables so far are simple: ...
3
votes
1answer
15 views

How can I exclude range overlaps if one range may be empty?

Suppose I want to ensure that, for any expected height in feet, I have a single, unambiguous classification. I create this table: CREATE TABLE heights_in_feet( size TEXT NOT NULL, min INTEGER NOT ...
11
votes
1answer
4k views

MATCH FULL vs MATCH SIMPLE in foreign key constraints

I've noticed a MATCH SIMPLE or MATCH FULL option in phpPgAdmin, but I can't find a description in the docs. The default is MATCH SIMPLE. How do they function?
1
vote
2answers
629 views

With MS SQL Server are the generated constraint names predictable?

When you create your primary key, and foreign key constraints in a CREATE TABLE script, there are named constraints that are created, such as FK__RecentlyVi__ScId__2764765D ... are these constraints ...
15
votes
3answers
14k views

check constraint does not work?

I have the following table. create table test ( id smallint unsigned AUTO_INCREMENT, age tinyint not null, primary key(id), check (age<20) ); The problem is that the CHECK ...
1
vote
1answer
76 views

Should child comment be treated as separate table?

I'm building a commenting system, currently my table indicates which comment is child with parent id in 1 table, I would like to know what is the best way of doing this? Current Table Scheme (1 ...
0
votes
1answer
21 views

Postgres constraint function on a single column

Is it possible to create a constraint in Postgres that will run a function, but only if a specific column is changed? Right now, I have this: ALTER TABLE public.employee ADD CONSTRAINT ...
4
votes
1answer
1k views

How to check foreign keys related to a table

How to see foreign keys related to a table in MySql? Background : I wanted to drop a table in MySql which has a foreign key constraint. When I do it I get this: Error Code: 1217. Cannot delete or ...
31
votes
2answers
14k views

Check constraint only one of three columns is non-null

I have a (SQL Server) table that contains 3 types of results: FLOAT, NVARCHAR(30), or DATETIME (3 separate columns). I want to ensure that for any given row, only one column has a result and the other ...
10
votes
5answers
664 views

Why does this UPDATE fail with a unique key constraint violation?

I'm an "accidental" DBA, relatively inexperienced and baffled by this problem. Running MS SQL Server 2012. The problem is with this UPDATE statement: UPDATE dbo.tAccts SET Ticket ...
0
votes
1answer
34 views

How to add a check constraint in Postgres without locking the table?

I would like to add a check constraint to a very large table. Something like: ALTER TABLE accounts ADD CONSTRAINT "nonnegative_balance" CHECK balance >= 0; Unfortunately Postgres (9.3, at least) ...
0
votes
1answer
46 views

is_not_trusted = 1 after Error-Free WITH CHECK CHECK CONSTRAINT

I'd like SQL Server 2005 SP4 to trust a certain foreign key constraint. Executing an ALTER TABLE statement that enables + checks the constraint returns Command(s) completed successfully yet ...
0
votes
1answer
24 views

Modify table constraint in PostgreSQL

Say I have a constraint ALTER TABLE distributors ADD CONSTRAINT zipchk CHECK (char_length(zipcode) = 5); that needs to be modified so that zipcode length is 6. Do I have the drop the constraint ...
8
votes
2answers
99 views

SQL Server equivalent of Oracle USING INDEX clause

Is there a SQL Server 2008 equivalent of the USING INDEX clause in Oracle? Specifically for the construct: CREATE TABLE c(c1 INT, c2 INT); CREATE INDEX ci ON c (c1, c2); ALTER TABLE c ADD CONSTRAINT ...
0
votes
1answer
35 views

Adding multiple constraints

I am trying to add constraints and I think i have an error in the code as its saying i cant add mutlple constrints. What is best way to add mutlple constraints I am using MSQL Server 2008 r2 CREATE ...
2
votes
0answers
41 views

Any drawbacks to referencing multiple tables from a single column?

I'm working on a system with the following entities: Projects Sections Activities There is one important constraint that needs to be enforced: Activities are always part of one project. ...
2
votes
0answers
22 views

sqlite3 foreign keys ignored

I am working on a small sqlite3 database for a small simple mailserver. I have created a new sqlite3 database and add executed this to pürepare it for data: BEGIN TRANSACTION; CREATE TABLE ...
1
vote
1answer
31 views

What is the best approach to find all fields that has (Foreign Key and Primary Key) constraints in a Mysql database?

I have a mysql database that has 250 tables. I would like to run a query to retrieve: tableName ; FieldName ; ConstaintName (Primary or foreign key). I could use ...
0
votes
1answer
23 views

Assign value to a field after checking a condition

I have this query: ALTER TABLE MERCHANTS ADD COLUMN merchant_image bytea, ADD COLUMN merchant_logo bytea, ADD COLUMN merchant_address VARCHAR(100), ADD COLUMN merchant_phone VARCHAR(50), ...
2
votes
1answer
833 views

How to set unique columns combination

see this table: CREATE TABLE IF NOT EXISTS `default_messages_users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `message_id` int(11) NOT NULL, `owner_user_id` int(11) NOT NULL, `to_user_id` ...
0
votes
0answers
13 views

Unique attributes as a group [duplicate]

create table test (a int, b int); I want to make a and b be unique, but as a whole. Example: a b - - 1 1 1 2 - this is ok, because even if the previous entry was 1, the b value is different 2 1 - ...
1
vote
1answer
33 views

Duplicate check constraint on multiple tables?

I have an integer value for a data to be included into two or three tables, Say it is part no. The integer value of part no must be between 1 to 8. I want to add that constraint into the tables. ...
0
votes
0answers
14 views

How to use Domains in oracle database

I am trying to learn about domains. As far as i understand, domains are user defined "types" that describe restrictions of its value. But how would i assign and use a domain in a given table in an ...
1
vote
1answer
45 views

Constrain/limit certain records in sql table definitions

Let's say I have posts on which users can leave a comment. And I want to limit the amount of comments to a certain post to 10, is it possible to add such constraint/restriction to the table? My guess ...
1
vote
2answers
394 views

Performance of single vs multiple column unique constraint

I'm using PostgreSQL 9.3. I want to understand if I have an option to make a constraint unique across the entire table vs. unique across a subset of the table (i.e. by using 2 columns in the unique ...
1
vote
1answer
31 views

Indirect constraints (foreign keys amongst three/four tables) [duplicate]

I have the next layout of tables: table COMPANY: - primary key pk_company table USERS: - primary key pk_users, - foreign key (fk_company) references COMPANY (pk_company) table GROUPS: <br> - ...
3
votes
1answer
148 views

Constrains relationship

I have the following design. Each user has it's own contacts, it's own hosts and assign those to a domain which belongs only to him. I want to insure that the host you assign to the domain belongs ...
10
votes
3answers
214 views

Constraint to enforce “at least one” or “exactly one” in a database

Say we have users and each user can have multiple email addresses CREATE TABLE emails ( user_id integer, email_address text, is_active boolean ) Some sample rows user_id | ...
5
votes
2answers
306 views

Conditional Foreign Key Relationship

I currently have a foreign key between two entities, and I would like to make that relation conditional to the entityType of one of the tables. Here's the hierachy of tables, this is done via FK ...
1
vote
1answer
25 views

Can I enforce one field being dependent on another?

I would like to know if it's possible to have two fields (in this case bits) in the same table where one is dependent on another. For example Check2 may only be true if Check1 is true. Note: I'm ...
9
votes
2answers
4k views

How can I help SQL Server recognize my indexed view column is NOT NULL-able?

I have the following indexed view defined in SQL Server 2008 (you can download a working schema from gist for testing purposes): CREATE VIEW dbo.balances WITH SCHEMABINDING AS SELECT user_id ...
1
vote
1answer
59 views

Enforce a single NULL end date per foreign key value using an index

I want to implement a Check Constraint across a date range and foreign key. I have a table created as: Primary Key Foreign Key DateStart DateEnd The ForeignKey can appear many times in the table ...
1
vote
1answer
36 views

Using REGEX_LIKE to Implement a Check Constraint

Background I am working on the database design for an application that tracks information about database development projects at my company. The project management office (PMO) assigns a ...
0
votes
1answer
94 views

Create an “int” column forced between 0 and 3

I would like to create a table with one column that would be of type "integer", and locked between 0 and 3. Is this possible? My goal would be to have this column so that I could just execute a ...
1
vote
1answer
485 views

Adding foreign keys constraint on databases used

We have a server with about 20 databases, all duplicates of the same original db, and we just noticed the original is missing all the foreign keys constraint for some unknown reason. So of course all ...
4
votes
1answer
293 views

How to enforce a constraint over multiple tables?

I have the following five tables: PRODUCT FEATURE PROVIDER PROVIDER_PRODUCT PROVIDER_FEATURE The logic is as follows: A generic PRODUCT can have one or more FEATUREs. There are different ...
3
votes
1answer
131 views

Enabling Constraint Silently Fails

Why would SQL Server silently fail to re-enable a foreign key constraint? I recently attempted to re-enable a number of constraints using ALTER TABLE. Most enabled successfully; however, minority of ...
2
votes
1answer
69 views

Can Indexes mitigate untrusted Constraint

I using sp_blitz and found two tables that have foreign keys that is untrusted. tried to enable the trust with: ALTER TABLE MyTableName WITH CHECK CHECK CONSTRAINT MyConstraintName; GO But got this ...
3
votes
3answers
131 views

Cap on number of rows matching a condition in Postgres

Say I have a db schema like this user_id text photo_id text date_created timestamp and I want to enforce a constraint that says "a user can only have 30 photos". A naive way to implement this would ...
0
votes
1answer
51 views

Is unique index combined with a “not null” constraint equivalent to a PK constraint?

I have these legacy table definitions (from here): CREATE TABLE [dbo].[JobItems] ( [ItemId] UNIQUEIDENTIFIER NOT NULL, -- lots of other columns CONSTRAINT [PrimaryKey_GUID_HERE] ...
2
votes
1answer
132 views

Foreign Key Constraint over two tables

I am trying to put the following entity-model into practice: We have a list of Payments, each Payment belongs to a certain store and is of a certain payment type (e.g. 10€ maintenance cost in ...
2
votes
1answer
151 views

Multi-column uniqueness constraint, checking a field has one of two values

I'd like to enforce that only one row in a database matches value A in column 1, and either value B or value C in column 2. A small example create table builders ( id text serial ); create table ...
3
votes
1answer
421 views

Postgres 9.3 - deletes terribly slow for 10 minutes after dropping indexes/constraints

If I run a script which drops indexes (17 of them, CONCURRENTLY makes no difference except that without it I get the occasional deadlock), then constraints (20 constraints on 18 tables) and then run a ...