Questions tagged [check-constraints]
That part of declarative referential integrity (DRI) where a column's permitted range of values is enforced by a Boolean predicate.
125
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Correct (as in normalized) way to express a relationship between 3 tables with complex(?) constraints?
I'll be using Postgres for the examples, but feel free to show examples in other databases if needed.
The simplified schema:
create table factory (
id serial primary key,
detail text not null
);
...
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2
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95
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DATE Constraint is ignored on insert
I must be missing something somewhere..
Azure SQL
DispatchedOn is a DateTime column
ALTER TABLE [table] WITH CHECK ADD CONSTRAINT [CK_ReportDate6MonthRollGreater] CHECK ((CONVERT([date],[...
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2
votes
1
answer
52
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Constraint checks on multiple association tables vs. unique association table that centralizes these constraint checks
I have the following database schema (MySQL 5.7):
I have assistants that may be linked to either:
one customer (might evolve to multiple customers in the future, hence the association table)
one or ...
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1
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24
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Why constraint fails on preventing the insert statement execution?
I have the following table:
-- laravel.spies definition
CREATE TABLE `spies` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(255) NOT NULL,
`surname` varchar(255) NOT NULL,
...
1
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3
answers
158
views
Alter a scalar UDF that is used in a check constraint in SQL Server 2012
I have a check constraint on a column that uses a scalar UDF. I have a requirement where I need to make changes to the UDF. Based on what I know, I need to drop the constraint, make changes to the UDF,...
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131
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Detailed error message from check constraints using exceptions?
I am trying to get a detailed error message when a check constraint is violated (in PostgreSQL).
One way to achieve that is to define a check constraint using a UDF that throws exceptions. However, ...
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156
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How to include "CHECK" constraint to backup done via phpMyAdmin?
When I export my database from phpMyAdmin (quick method), it does not include CHECK constraints. However, when I run SHOW CREATE TABLE table, I see the constraints. Moreover, foreign constraints are ...
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751
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Why won't this UDF work in this check constraint?
I’m trying to use a UDF as an alternative to using a SELECT command within a check constraint. I need to put a constraint on the report table to ensure the signedBy field is the PK of a personnel ...
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1
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25
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Ensure value is in list when inserting / updating
is it possible to ensure that a value is in a list of values defined in another table? For instance by using a check constraint?
I was thinking about a construct like this:
CREATE OR REPLACE TABLE `...
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What characters are rejected during this check constraint clause in a SQL Server stored procedure?
I tried to import a record with a semicolon in the addr field. Once I removed the semicolon from the import file, the following error went away:
Database error occurred SQLSATE = 23000
[Microsoft][...
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519
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What is the current state (2022) of using UDFs in a CHECK constraint in SQL Server?
SQL Server allows the use of User-Defined Functions (UDFs) in CHECK constraints - which has a number of use-cases - which I won't get into - but I was recently faced with implementing a non-trivial ...
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3
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734
views
How Does SQL (In my case SQL Server) Evaluate a Unique Constraint On Multiple Columns?
Given the following table
CREATE TABLE example (
id int NOT NULL IDENTITY(1,1),
strA NVARCHAR(10) NULL,
strB NVARCHAR(10) NULL,
CONSTRAINT [pk_id] PRIMARY KEY (id)
CONSTRAINT [...
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1
answer
54
views
Impose limits on number of records stored in a table
Assume we have a table with following schema:
favorites{
UserID
CategoryID
}
How can I enforce a policy which ensures each users has at least 3 categories and at most 5 categories. Is it ...
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2
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753
views
Validate a column if it contains a character, using check constraint in postgresql
Table:
create table tempchkconstraint (
colcode varchar,
colname varchar,
lastmoddate timestamp without time zone
);
Need to validate the column 'colcode' if any data with character '-' is ...
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1
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2
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2k
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Allow SQL column to only be updated if NULL
tldr: Is it possible to create a constraint that enforces: only allow update to column if its current value is NULL.
I’m using Postgresql to update a column from NULL to a foreign key when the user ...
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2
answers
2k
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Create unique index based on two columns (bi-directional)
I want to make a check constraint or a unique index to validate that I'm not creating duplicates within my table based on 2 columns, I do not want the same two IDs in these columns.
Thinking about ...
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1
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397
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SQL Server Scalar UDF Parallelism Mystery!
Referencing this blog post by Erik Darling on the website of my favorite SQL Server guru - Brent Ozar:
When you select from that table alone, it shows "CouldNotGenerateValidParallelPlan".
...
-3
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1
answer
1k
views
How to store only US/Canada phone numbers in postgres?
I want to store only US and Canada phone numbers in a Postgres TEXT column. I don't want to use pg_libphonenumber.
What CHECK constraints should I be using for this purpose?
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2
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1k
views
constraint check values with regular expression
In a table with a field code, I want to authorize the user to choose one value among a list.
Here is a sample of the values of the list :
A|AG|AL|AS|B|C|D|DA
I added a constraint on code like this :
...
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338
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data model limit rows per user
This is regarding to postgres that I was asked to create data model which has a relationship with user.
For example a new data model called Comment M:1 User, but while creating the data model is it ...
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84
views
Does putting constraints decrease the required size to store my data in SQL Server?
I would like to know if putting check constraints decrease the required column size or not? For example, when I create an int column and a check constraint on it to store the numbers between 100 and ...
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Column constraint based on values in another column
I have a PostgreSQL table phase_steps, with the following example rows:
phase_step_id|step_type|step_status|
-------------+---------+-----------+
1| RESEARCH| |
2| ...
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262
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how do I restrict a specific row's columns to have only a specific value set?
I have the following table
CREATE TABLE `mview_state` (
`state_id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'View State ID',
`view_id` varchar(255) DEFAULT NULL COMMENT 'View ID',
`mode` ...
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1
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2
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419
views
Check constraint to guarantee ltree ancestors
I ran into an issue where we had a tree structure that looked like this:
select title, tree_path from my_table where tree_path <@ '3';
title | tree_path
-----------------------
item A | 3
...
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1
vote
3
answers
546
views
Constraint to prevent immediate loop in hierarchy
I have a companies table:
CREATE TABLE companies (
id bigserial,
name varchar(255) NOT NULL
PRIMARY KEY (id)
)
I want companies to have parents and childs. A company might have many parent and ...
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1
vote
1
answer
440
views
Is it more efficient to create check constraints on PostgreSQL table before or after bulk load?
I am creating a table in PostgreSQL and bulk load with data first. PostgreSQL's documentation recommends to insert large volumes of data first and then create indexes and foreign key constraints. What'...
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1
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192
views
Add constraint to table creation in SQL
I have to create a table Product with elements P, PType, PName, Price and Origin.
I need to have the constraint that all products with PType "Meat" must have "Europe" as Origin. I ...
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878
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Retrieve Names of Check Constraints Specific to a Column
PostgreSQL 12
When I rename a column in a table, I would like to dynamically rename the matching check constraints as well.
I have a hypothetical table:
CREATE TABLE hypothetical_table (
id SERIAL ...
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115
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PostgreSQL - Removing Unused Index on Check Constraint column
I used the script from this blog to identify the unused index on my database. It returns an index which is on a column called result where I have a check constraint on that column.
So removing this ...
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3
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2
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238
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How to implement an association with restrictions
I'm working on an SQL database of useful plants. I'd like to be able to allow users to annotate the plants with a set of hierarchical categories and tags. For example:
category: medicine
body part: ...
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2k
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CHECK Constraint to enforce upper case letter and pattern match
For one of my columns I am trying to enforce a pattern. The first letter should be D upper case, and the remaining 3 characters should be digits. For example:
D678, D890, D000
I'm quite new with CHECK ...
user223014
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126
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Check constraint on a pair of columns
I have a table with this structure:
create table licence_report
(
id bigint default nextval('licence_report_id_seq'::regclass) not null,
created ...
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1
vote
1
answer
555
views
Adding a check constraint on a new column with default value on a large table
I have a large table (1–2m rows) and need to add a column. It is an integer column with a default of 0. I am also adding a check constraint that column >= 0.
Currently, I am making the change in ...
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43
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CHECK CONSTRAINT isn't identifying breaches of a constraint but DBCC CHECKCONSTRAINTS does
I have a table full of data and I have a constraint on a field in that table that is setup to ensure the total of 2 fields equals a 3rd field. For example:
ALTER TABLE [dbo].[Table1]
WITH NOCHECK ADD ...
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1
answer
953
views
Check constraint age 18< [closed]
Hello I need to create a constraint that chekc the user is 18< before listenning to certain songs but idk how... I tried this :
ALTER TABLE Historique_ecoute
DROP CONSTRAINT IF EXISTS ...
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1
answer
32
views
Adding a dropped check-constraint what queries the table
I'm using a Postgres to preist a hierarchical data set; the table I'm using is something like this:
CREATE TABLE layers (
bucket text not null,
uniq_id serial not null,
name ...
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0
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61
views
Check constraint on grouped conditions
Take the following table as an example:
GroupID AlphaID BetaID
1 0 1
1 1 1
1 2 2
2 0 1
2 1 2
...
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1
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400
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MySQL - is there a way to implement a CHECK constraint after creating the table?
I created a table and after entering all the data, I found that I had missed a CHECK constraint in the CREATE TABLE statement.
create table jims_faculty
( fac_id int primary key,
fac_name varchar(15) ...
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14
votes
1
answer
2k
views
How can I enforce that values in a table column match the Regular Expression "[axyto0-9\s]{0,2}[\s0-9]{0,10}"?
I have a table as below
CREATE TABLE dbo.DemoTable
(
Value VARCHAR(12)
)
I would like to constrain it to only contain rows where Value matches the following pattern
[axyto0-9\s]{0,2}[\s0-9]{0,10}
...
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432
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Can I tell Postgres that a new constraint is valid without actually running the check?
I have a constraint that ensures one of three columns is populated, and I'm adding a new column, so I'm replacing the old constraint with a four-column version. Since I know from the old constraint ...
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2
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591
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Should fields that are set to Not Null also have a constraint refusing empty strings?
Any field that I would expect a value (Like an orderNumber or customerNumber) I would set as not nullable.
If I'm expecting the value of the field to be not null, shouldn't I also always have a ...
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3
answers
1k
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Foreign key reference to column that is no primary key
I know, foreign keys should uniquely identify rows and therefore reference a primary key.
However, consider my example: There are 4 pre-defined categories, and for some combinations of values for ...
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1
vote
1
answer
58
views
Adding constraint to an existing table column
I have a table that doesnt have any constraint on them like this
CREATE TABLE SomeTable
(
Id int NOT NULL,
Type varchar(50),
)
insert into SomeTable values (12,'Exchange-Student');
Now I ...
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1
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0
answers
64
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Best way to handle this type of constraint
Guidance please. We have a small configuration table where we need to ensure only 1 record has bit checked. In the past, we have done check constraint with function that checks count, which we are ...
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1
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491
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Sqlite - Limit Characters for different parts of one String with Check
I have to make sure that any inserted Email has the format: "[email protected]"
X and Y may only contain letters and numbers and Z can only have Letters.
I tried something like this, but i cant figure out how ...
0
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1
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443
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SQLite, ASCII Characters 0x20 to 0x7E Check Constraint
I have the following table which I'm trying to limit the column name to ASCII characters ranging from 0x20 to 0x7E. Why is it not working?
CREATE TABLE test
(
id INTEGER NOT NULL,
name TEXT ...
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1
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42
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Constraints between tables on a variable
im aiming to add a constraint on the number of bicycles allowed to be stored in each terminal - the number differing between terminals.
These are my original tables
create table terminal(
...
3
votes
1
answer
3k
views
Compound unique constraint with NULL values
With the following table structure
CREATE TABLE favorite_comments(
id SERIAL PRIMARY KEY NOT NULL,
opinion_id BIGINT REFERENCES opinions(id),
review_id BIGINT REFERENCES reviews(id),
...
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2k
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Constrain array values to an allowed set of values
I would like to set up a CHECK constraint that makes sure that a text[] column's elements contain only certain values.
Setting up an example:
CREATE TABLE foo(
countries text[]
);
INSERT INTO foo ...
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1
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2k
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Create a foreign key to a table that doesn't exist in postgres
I'm trying to put together a solution where I have a bunch of script files that contain my schema creation. Something similar to Visual Studio's SQL Project, but for Postgres.
My problem is that the ...
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