I want to use a range constraint in creating a table, as it seems more elegant than what I'm currently doing:
DROP TABLE IF EXISTS "coa_sandbox"."account_list";
CREATE TABLE "coa_sandbox"."account_list" (
id serial unique not null,
account_number int unique not null CONSTRAINT within_range CHECK (account_number >= 10000 AND account_number <= 99999),
account_name text unique not null
) WITH (oids = false);
Maybe it's silly, but I think using int4range seems to be a more professional approach.
I've been using Erwin Brandstetter's solution to this problem [https://stackoverflow.com/a/35028185] as inspiration, without success. I re-created my table above, without the constraint, then tried altering the table. I started with:
ALTER TABLE "coa_sandbox"."account_list" ADD CONSTRAINT within_range
CHECK ("account_number" = ANY ('{9999,99999}'::int4range[]));
... with this result:
Error in query: ERROR: malformed range literal: "9999"
DETAIL: Missing left parenthesis or bracket.
Note that I'm using Adminer 4.7.8 to perform these queries.
I've continued trying with different combinations of brackets, curly braces & parenthesis, using the error details and my intermediate level of knowledge regarding these items in Perl as influence.
I got nuthin'. I've been searching the PostgreSQL docs for details on syntax, and if the solution is evident then I'm just not seeing it.
Will someone please set me straight on this? If my initial working solution is the best approach, please tell me. If I'm heading in the right direction but missing the correct details, please tell me what I'm missing.
Thank you.
Finally figured it out. The CONTAINED IN (<#) operator is what I was looking for.
The statement I've wanted is:
DROP TABLE IF EXISTS "coa_sandbox"."account_list";
CREATE TABLE "coa_sandbox"."account_list" (
id serial unique not null,
account_number int unique not null CONSTRAINT within_range
CHECK ("account_number" <# int4range(10000,100000)),
account_name text unique not null
) WITH (oids = false);
Related
I have a question I know this was posted many times but I didn't find an answer to my problem. The problem is that I have a table and a column "id" I want it to be unique number just as normal. This type of column is serial and the next value after each insert is coming from a sequence so everything seems to be all right but it still sometimes shows this error. I don't know why. In the documentation, it says the sequence is foolproof and always works. If I add a UNIQUE constraint to that column will it help? I worked before many times on Postres but this error is showing for me for the first time. I did everything as normal and I never had this problem before. Can you help me to find the answer that can be used in the future for all tables that will be created? Let's say we have something easy like this:
CREATE TABLE comments
(
id serial NOT NULL,
some_column text NOT NULL,
CONSTRAINT id_pkey PRIMARY KEY (id)
)
WITH (
OIDS=FALSE
);
ALTER TABLE interesting.comments OWNER TO postgres;
If i add:
ALTER TABLE comments ADD CONSTRAINT id_id_key UNIQUE(id)
Will if be enough or is there some other thing that should be done?
This article explains that your sequence might be out of sync and that you have to manually bring it back in sync.
An excerpt from the article in case the URL changes:
If you get this message when trying to insert data into a PostgreSQL
database:
ERROR: duplicate key violates unique constraint
That likely means that the primary key sequence in the table you're
working with has somehow become out of sync, likely because of a mass
import process (or something along those lines). Call it a "bug by
design", but it seems that you have to manually reset the a primary
key index after restoring from a dump file. At any rate, to see if
your values are out of sync, run these two commands:
SELECT MAX(the_primary_key) FROM the_table;
SELECT nextval('the_primary_key_sequence');
If the first value is higher than the second value, your sequence is
out of sync. Back up your PG database (just in case), then run this command:
SELECT setval('the_primary_key_sequence', (SELECT MAX(the_primary_key) FROM the_table)+1);
That will set the sequence to the next available value that's higher
than any existing primary key in the sequence.
Intro
I also encountered this problem and the solution proposed by #adamo was basically the right solution. However, I had to invest a lot of time in the details, which is why I am now writing a new answer in order to save this time for others.
Case
My case was as follows: There was a table that was filled with data using an app. Now a new entry had to be inserted manually via SQL. After that the sequence was out of sync and no more records could be inserted via the app.
Solution
As mentioned in the answer from #adamo, the sequence must be synchronized manually. For this purpose the name of the sequence is needed. For Postgres, the name of the sequence can be determined with the command PG_GET_SERIAL_SEQUENCE. Most examples use lower case table names. In my case the tables were created by an ORM middleware (like Hibernate or Entity Framework Core etc.) and their names all started with a capital letter.
In an e-mail from 2004 (link) I got the right hint.
(Let's assume for all examples, that Foo is the table's name and Foo_id the related column.)
Command to get the sequence name:
SELECT PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id');
So, the table name must be in double quotes, surrounded by single quotes.
1. Validate, that the sequence is out-of-sync
SELECT CURRVAL(PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id')) AS "Current Value", MAX("Foo_id") AS "Max Value" FROM "Foo";
When the Current Value is less than Max Value, your sequence is out-of-sync.
2. Correction
SELECT SETVAL((SELECT PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id')), (SELECT (MAX("Foo_id") + 1) FROM "Foo"), FALSE);
Replace the table_name to your actual name of the table.
Gives the current last id for the table. Note it that for next step.
SELECT MAX(id) FROM table_name;
Get the next id sequence according to postgresql. Make sure this id is higher than the current max id we get from step 1
SELECT nextVal('"table_name_id_seq"');
if it's not higher than then use this step 3 to update the next sequence.
SELECT setval('"table_name_id_seq"', (SELECT MAX(id) FROM table_name)+1);
The primary key is already protecting you from inserting duplicate values, as you're experiencing when you get that error. Adding another unique constraint isn't necessary to do that.
The "duplicate key" error is telling you that the work was not done because it would produce a duplicate key, not that it discovered a duplicate key already commited to the table.
For future searchs, use ON CONFLICT DO NOTHING.
Referrence - https://www.calazan.com/how-to-reset-the-primary-key-sequence-in-postgresql-with-django/
I had the same problem try this:
python manage.py sqlsequencereset table_name
Eg:
python manage.py sqlsequencereset auth
you need to run this in production settings(if you have)
and you need Postgres installed to run this on the server
From http://www.postgresql.org/docs/current/interactive/datatype.html
Note: Prior to PostgreSQL 7.3, serial implied UNIQUE. This is no longer automatic. If you wish a serial column to be in a unique constraint or a primary key, it must now be specified, same as with any other data type.
In my case carate table script is:
CREATE TABLE public."Survey_symptom_binds"
(
id integer NOT NULL DEFAULT nextval('"Survey_symptom_binds_id_seq"'::regclass),
survey_id integer,
"order" smallint,
symptom_id integer,
CONSTRAINT "Survey_symptom_binds_pkey" PRIMARY KEY (id)
)
SO:
SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass),
MAX(id)
FROM public."Survey_symptom_binds";
SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass) less than MAX(id) !!!
Try to fix the proble:
SELECT setval('"Survey_symptom_binds_id_seq"', (SELECT MAX(id) FROM public."Survey_symptom_binds")+1);
Good Luck every one!
I had the same problem. It was because of the type of my relations. I had a table property which related to both states and cities. So, at first I had a relation from property to states as OneToOne, and the same for cities. And I had the same error "duplicate key violates unique constraint". That means that: I can only have one property related to one state and city. But that doesnt make sense, because a city can have multiple properties. So the problem is the relation. The relation should be ManyToOne. Many properties to One city
Table name started with a capital letter if tables were created by an ORM middleware (like Hibernate or Entity Framework Core etc.)
SELECT setval('"Table_name_Id_seq"', (SELECT MAX("Id") FROM "Table_name") + 1)
WHERE
NOT EXISTS (
SELECT *
FROM (SELECT CURRVAL(PG_GET_SERIAL_SEQUENCE('"Table_name"', 'Id')) AS seq, MAX("Id") AS max_id
FROM "Table_name") AS seq_table
WHERE seq > max_id
)
try that CLI
it's just a suggestion to enhance the adamo code (thanks a lot adamo)
SELECT setval('tableName_columnName_seq', (SELECT MAX(columnName) FROM tableName));
For programatically solution at Django. Based on Paolo Melchiorre's answer, I wrote a chunk as a function to be called before any .save()
from django.db import connection
def setSqlCursor(db_table):
sql = """SELECT pg_catalog.setval(pg_get_serial_sequence('"""+db_table+"""', 'id'), MAX(id)) FROM """+db_table+""";"""
with connection.cursor() as cursor:
cursor.execute(sql)
I have similar problem but I solved it by removing all the foreign key in my Postgresql
Hello I am fairly new to PostgreSQL, I keep getting the following error code:
ERROR: relation "contact" does not exist
********** Error **********
ERROR: relation "contact" does not exist
SQL state: 42P01
Questions regarding this error code have been mentioned a lot on Stack Overflow and online, however I have tried checking for any braces that may change the letter case sensitivity of my code and was unable to find any.
This is how I've attempted to create the table:
CREATE TABLE CONTACT (
CONTACT_ID INTEGER,
BUILDING_NO INTEGER,
POSTCODE VARCHAR,
PHONE_NO INTEGER,
EMAIL VARCHAR,
CONSTRAINT PK_CONTACT_ID PRIMARY KEY (CONTACT_ID));
I would appreciate anyones help, and am sorry if this question may have been repeated, thank you guys :)
The issue is that you are creating your objects (tables) in the wrong order.
Create contact before you create tables that use contact as a foreign key-- or, create the foreign keys after you've created all your tables. The first table "student" is referencing contact, which has not been created yet.
EDIT:
Also, your phone number fields should not be integers, they should be text or varchar. If you're dead set on a numeric type, use bigint instead if integer.
I copied and pasted you code and it worked for me. Could it be something with your postgresql setup?
EDITS BELOW
Alright so I'm going to add more to the solution
Like Joe Love Said, You have issues with the ordering. The proper ordering of your tables should be something like Contact, Status, Student, Company, Application and then the rest of the queries.
In your Application Table, the line
CONSTRAINT FK_STATUS_ID FOREIGN KEY (STATUS_ID) REFERENCES STATUS (STATUS_ID),
Will give you an error.
Its because in the STATUS Table, you have set the ID as a VARCHAR and in the Application table, the Status is an INTEGER.
You still have some issues with the Application query referencing the Company Table as well. If you fix them, you should be good.
I've tried searching for about an hour through all the Foreign Key / Collation Questions but I can't find something even remotely close to my question.
I have 2 tables from two different software vendors sitting in the same database. One vendor hard codes their collations to Latin1_General_BIN while the other uses the Database Default (in this case Latin1_General_CI_AS). Is it possible, without altering any of the columns, to create Foreign Keys between these two Collation Types?
Typically you would simply change one but in this case the Tables are very sensitive and I'm not allowed to make such a change but I have to create a Foreign Key due to a piece of logic in a Trigger that reads data between these two tables only if it finds a Foreign Key:
SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE
WHERE CONSTRAINT_NAME =
(
SELECT name FROM sys.foreign_keys
WHERE parent_object_id = OBJECT_ID( 'Table1' )
AND referenced_object_id = OBJECT_ID( 'Table2' )
)
Any help would really be appreciate
P.S. I just can't seem to figure out how this code thing works if anyone would help me out, I put in the 4 required spaces but it's still just displaying my code as text :(
Adding a foreign key constraint from a field of one collation to a field of another collation can't be done. You will get error message 1757.
Either change the collation of one of the tables or create a work around with a new column that is used instead with the correct collation or create surrogate key columns with integers used for referencing.
If nothing else works and you really really need to fix this type of constraint and performance is not an issue, add a check constraints and/or triggers that will check the referential integrity of data put into the tables. These rules will have to cast all values in one table to the collation of the other in order to compare values so it will be slow and it will be really tricky for you to get use of indexes, proceed with caution.
For example you could have an insert trigger on the referencing table that check if a record with the inserted string exists in the referenced table. Then you would also have to add an update and delete trigger for the referenced table so that it doesn't fall out of range of values that are referenced by records in the referencing table or which cascades updates/deletes. Basically you replicate what foreign keys are and it gets really slow and scales horribly.
Short answer: don't do it, let the tables stay untied or fix the collation of one of them.
Sweet, I think the solution is very elegant. I'm writing it as an answer purely as it's the full alternative that closest resembles the required solution. But I'm going to mark your answer as the answer as it's the one that correctly answers my original question.
Right, so first what I did, was I got permission from the vendor who's trigger requires the foreign key, to create a new column in their table as a persisted computed column in the collation of the other vendors table:
DECLARE #Collation nvarchar(100)
DECLARE #SQL nvarchar(1000)
SET #Collation = ( SELECT collation_name FROM sys.columns WHERE OBJECT_ID IN ( SELECT OBJECT_ID FROM sys.objects WHERE type = 'U' AND name = 'Vendor1Table' ) AND name = 'Vendor1Column' )
SET #SQL = 'ALTER TABLE [Vendor2Table] ADD [Vendor2ComputedColumn] AS [Vendor2Column] COLLATE ' + #Collation + ' PERSISTED'
EXECUTE( #SQL )
GO
Next up, I added a candidate key to the computed column:
ALTER TABLE [Vendor2Table] ADD CONSTRAINT [CCUNQ1_x] UNIQUE NONCLUSTERED
(
[Vendor2ComputedColumn] ASC
)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
ON [PRIMARY]
GO
Then, I simply created the foreign key to the computed column:
ALTER TABLE [dbo].[Vendor1Table] WITH CHECK ADD CONSTRAINT [CCFOK01_x] FOREIGN KEY ( [Vendor1Column] )
REFERENCES [dbo].[Vendor2Table] ( [Vendor2ComputedColumn] )
GO
ALTER TABLE [dbo].[Vendor1Table] CHECK CONSTRAINT [CCFOK01_x]
GO
and finally, the original SQL Script passes with flying colours:
SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE
WHERE CONSTRAINT_NAME =
(
SELECT name FROM sys.foreign_keys
WHERE parent_object_id = OBJECT_ID( 'Vendor1Table' )
AND referenced_object_id = OBJECT_ID( 'Vendor2Table' )
)
Hopefully this small walkthrough helps some other soul some day :)
Thanks for the assist David, appreciate it!
I have a question I know this was posted many times but I didn't find an answer to my problem. The problem is that I have a table and a column "id" I want it to be unique number just as normal. This type of column is serial and the next value after each insert is coming from a sequence so everything seems to be all right but it still sometimes shows this error. I don't know why. In the documentation, it says the sequence is foolproof and always works. If I add a UNIQUE constraint to that column will it help? I worked before many times on Postres but this error is showing for me for the first time. I did everything as normal and I never had this problem before. Can you help me to find the answer that can be used in the future for all tables that will be created? Let's say we have something easy like this:
CREATE TABLE comments
(
id serial NOT NULL,
some_column text NOT NULL,
CONSTRAINT id_pkey PRIMARY KEY (id)
)
WITH (
OIDS=FALSE
);
ALTER TABLE interesting.comments OWNER TO postgres;
If i add:
ALTER TABLE comments ADD CONSTRAINT id_id_key UNIQUE(id)
Will if be enough or is there some other thing that should be done?
This article explains that your sequence might be out of sync and that you have to manually bring it back in sync.
An excerpt from the article in case the URL changes:
If you get this message when trying to insert data into a PostgreSQL
database:
ERROR: duplicate key violates unique constraint
That likely means that the primary key sequence in the table you're
working with has somehow become out of sync, likely because of a mass
import process (or something along those lines). Call it a "bug by
design", but it seems that you have to manually reset the a primary
key index after restoring from a dump file. At any rate, to see if
your values are out of sync, run these two commands:
SELECT MAX(the_primary_key) FROM the_table;
SELECT nextval('the_primary_key_sequence');
If the first value is higher than the second value, your sequence is
out of sync. Back up your PG database (just in case), then run this command:
SELECT setval('the_primary_key_sequence', (SELECT MAX(the_primary_key) FROM the_table)+1);
That will set the sequence to the next available value that's higher
than any existing primary key in the sequence.
Intro
I also encountered this problem and the solution proposed by #adamo was basically the right solution. However, I had to invest a lot of time in the details, which is why I am now writing a new answer in order to save this time for others.
Case
My case was as follows: There was a table that was filled with data using an app. Now a new entry had to be inserted manually via SQL. After that the sequence was out of sync and no more records could be inserted via the app.
Solution
As mentioned in the answer from #adamo, the sequence must be synchronized manually. For this purpose the name of the sequence is needed. For Postgres, the name of the sequence can be determined with the command PG_GET_SERIAL_SEQUENCE. Most examples use lower case table names. In my case the tables were created by an ORM middleware (like Hibernate or Entity Framework Core etc.) and their names all started with a capital letter.
In an e-mail from 2004 (link) I got the right hint.
(Let's assume for all examples, that Foo is the table's name and Foo_id the related column.)
Command to get the sequence name:
SELECT PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id');
So, the table name must be in double quotes, surrounded by single quotes.
1. Validate, that the sequence is out-of-sync
SELECT CURRVAL(PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id')) AS "Current Value", MAX("Foo_id") AS "Max Value" FROM "Foo";
When the Current Value is less than Max Value, your sequence is out-of-sync.
2. Correction
SELECT SETVAL((SELECT PG_GET_SERIAL_SEQUENCE('"Foo"', 'Foo_id')), (SELECT (MAX("Foo_id") + 1) FROM "Foo"), FALSE);
Replace the table_name to your actual name of the table.
Gives the current last id for the table. Note it that for next step.
SELECT MAX(id) FROM table_name;
Get the next id sequence according to postgresql. Make sure this id is higher than the current max id we get from step 1
SELECT nextVal('"table_name_id_seq"');
if it's not higher than then use this step 3 to update the next sequence.
SELECT setval('"table_name_id_seq"', (SELECT MAX(id) FROM table_name)+1);
The primary key is already protecting you from inserting duplicate values, as you're experiencing when you get that error. Adding another unique constraint isn't necessary to do that.
The "duplicate key" error is telling you that the work was not done because it would produce a duplicate key, not that it discovered a duplicate key already commited to the table.
For future searchs, use ON CONFLICT DO NOTHING.
Referrence - https://www.calazan.com/how-to-reset-the-primary-key-sequence-in-postgresql-with-django/
I had the same problem try this:
python manage.py sqlsequencereset table_name
Eg:
python manage.py sqlsequencereset auth
you need to run this in production settings(if you have)
and you need Postgres installed to run this on the server
From http://www.postgresql.org/docs/current/interactive/datatype.html
Note: Prior to PostgreSQL 7.3, serial implied UNIQUE. This is no longer automatic. If you wish a serial column to be in a unique constraint or a primary key, it must now be specified, same as with any other data type.
In my case carate table script is:
CREATE TABLE public."Survey_symptom_binds"
(
id integer NOT NULL DEFAULT nextval('"Survey_symptom_binds_id_seq"'::regclass),
survey_id integer,
"order" smallint,
symptom_id integer,
CONSTRAINT "Survey_symptom_binds_pkey" PRIMARY KEY (id)
)
SO:
SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass),
MAX(id)
FROM public."Survey_symptom_binds";
SELECT nextval('"Survey_symptom_binds_id_seq"'::regclass) less than MAX(id) !!!
Try to fix the proble:
SELECT setval('"Survey_symptom_binds_id_seq"', (SELECT MAX(id) FROM public."Survey_symptom_binds")+1);
Good Luck every one!
I had the same problem. It was because of the type of my relations. I had a table property which related to both states and cities. So, at first I had a relation from property to states as OneToOne, and the same for cities. And I had the same error "duplicate key violates unique constraint". That means that: I can only have one property related to one state and city. But that doesnt make sense, because a city can have multiple properties. So the problem is the relation. The relation should be ManyToOne. Many properties to One city
Table name started with a capital letter if tables were created by an ORM middleware (like Hibernate or Entity Framework Core etc.)
SELECT setval('"Table_name_Id_seq"', (SELECT MAX("Id") FROM "Table_name") + 1)
WHERE
NOT EXISTS (
SELECT *
FROM (SELECT CURRVAL(PG_GET_SERIAL_SEQUENCE('"Table_name"', 'Id')) AS seq, MAX("Id") AS max_id
FROM "Table_name") AS seq_table
WHERE seq > max_id
)
try that CLI
it's just a suggestion to enhance the adamo code (thanks a lot adamo)
SELECT setval('tableName_columnName_seq', (SELECT MAX(columnName) FROM tableName));
For programatically solution at Django. Based on Paolo Melchiorre's answer, I wrote a chunk as a function to be called before any .save()
from django.db import connection
def setSqlCursor(db_table):
sql = """SELECT pg_catalog.setval(pg_get_serial_sequence('"""+db_table+"""', 'id'), MAX(id)) FROM """+db_table+""";"""
with connection.cursor() as cursor:
cursor.execute(sql)
I have similar problem but I solved it by removing all the foreign key in my Postgresql
Sorry if this is a dead simple question but I'm confused from the documentation and I'm not getting any clear answers from searching the web.
If I have the following table schema:
CREATE TABLE footable
(
foo character varying(10) NOT NULL,
bar timestamp without time zone,
CONSTRAINT pk_foo PRIMARY KEY (foo)
);
and then use the query:
SELECT bar FROM footable WHERE foo = '1234567890';
Will the select query find the given row by searching an index or not? In other word: does the table have a primary key (which is foo) or not?
Just to get it clear. I'm used to specifying "PRIMARY KEY" after the column I'm specifying like this:
"...foo character varying(10) PRIMARY KEY, ..."
Does it change anything?
Why not look at the query plan and find out yourself? The query plan will tell you exactly what indexes are being used, so you don't have to guess. Here's how to do it:
http://www.postgresql.org/docs/current/static/sql-explain.html
But in general, it should use the index in this case since you specified the primary key in the where clause and you didn't use something that could prevent it from using it (a LIKE, for example).
It's always best to look at the query plan to verify it for sure, then there's no doubt.
In both cases, the primary key can be used but it depends. The optimizer will make a choice depending on the amount of data, the statistics, etc.
Naming the constraint can make debugging and error handling easier, you know what constraint is violated. Without a name, it can be confusing.