I have a SQL script but there is an issue with the order of the statements in the script
e.g.
INSERT INTO PERMISSIONS_FOR_ROLE (ROLE_ID, PERMISSION_ID) VALUES (3, 8);
INSERT INTO permissions (id, name) VALUES (8, 'update');
The order of occurrence in the script should have been reverse! And this results in a error because the foreign key with id 8 is not yet inserted when the first statement executes
leading to:
[Code: -177, SQL State: 23503] integrity constraint violation:
foreign key no parent; PERMISSIONS_FOR_ROLE_PERM_FK table: PERMISSIONS_FOR_ROLE value: 8
statements used to create the relationships are as below
create table PERMISSIONS ( ID bigint not null, NAME varchar(255), primary key (ID) );
create table PERMISSIONS_FOR_ROLE ( ROLE_ID bigint not null, PERMISSION_ID bigint not null, primary key (ROLE_ID, PERMISSION_ID) );
alter table PERMISSIONS_FOR_ROLE add constraint permissions_for_role_perm_fk foreign key (PERMISSION_ID) references PERMISSIONS;
Any suggestions on how to execute such a script ? I tried manually changing the order and the script executes properly but is there any other way to do it as its run as part of a ANT build target.
For mass inserts with very large scripts that are out of order, you can disable referential integrity checks with:
SET DATABASE REFERENTIAL INTEGRITY FALSE
see http://hsqldb.org/doc/2.0/guide/management-chapt.html#mtc_sql_settings on how to check for possible violations after the insert.
Related
These are the tables I already have:
CREATE TABLE Gyartok
(
GyID INT IDENTITY(2, 3),
Nev VARCHAR(20),
CONSTRAINT PK_Gyartok PRIMARY KEY (GyID)
)
CREATE TABLE Focicsuka
(
CsID INT IDENTITY(2, 2),
Meret INT,
CONSTRAINT PK_Focicsuka PRIMARY KEY (CsID)
)
CREATE TABLE FcsGyartjaGya
(
GyID INT IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1
FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2
FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya
PRIMARY KEY (GyID, CsID)
)
The problem is that every time I try to add new values to the table (like such)
INSERT INTO FcsGyartjaGya (Ar) VALUES (300);
I get an error saying I didn't initialize the CsID INT column:
Cannot insert the value NULL into column 'CsID', table 'Lab3.dbo.FcsGyartjaGya'; column does not allow nulls. INSERT fails.
I know I must initialize it with something, but I have no idea what do to it with, because IDENTITY(x, y) doesn't work (it's occupied by another column already) and adding another parameter to the code (like such)
INSERT INTO FcsGyartjaGya (Ar, CsID) VALUES (300, 7);
creates another error which says
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Lab3a", table "dbo.Gyartok", column 'GyID'.
It is important to note that I already filled every column with data, so that couldn't be the problem.
As I mention in the comments, your INSERT will work fine, provided the stars align correctly. For your table Gyartok you have GyID as your PRIMARY KEY, which is defined as a IDENTITY(2,3); so the first value generated is 2 and then each row attempted to be INSERTed will increment by 3.
So, if we run the following, we get the IDs 2, 5, 7 and 17. (11 and 14 are skipped as the INSERT failed).
CREATE TABLE Gyartok (
GyID INT IDENTITY(2, 3),
Nev VARCHAR(20),
CONSTRAINT PK_Gyartok PRIMARY KEY (GyID)
);
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES ('asdfjahsbvd'),
('ashjkgdfakd'),
('kldfbhjo');
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES (REPLICATE('A',25)), --Force a truncation error
('ashjkgdfakd');
GO
INSERT INTO dbo.Gyartok (Nev)
VALUES (REPLICATE('A',15));
Let's now add some data for your other table:
CREATE TABLE Focicsuka (
CsID INT IDENTITY(2, 2),
Meret INT,
CONSTRAINT PK_Focicsuka PRIMARY KEY (CsID)
)
INSERT INTO dbo.Focicsuka (Meret)
VALUES(12),
(25);
Now we want to INSERT into the table FcsGyartjaGya, defined as the following:
CREATE TABLE FcsGyartjaGya (
GyID INT IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1 FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2 FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya PRIMARY KEY (GyID, CsID)
)
This has a IDENTITY on GyID, but defined as an IDENTITY(3,2), so the first value is 3 and then incremented by 2.
As this has 2 foreign keys, on GyID and CsID when we INSERT the row the values must appear in the respective tables. As GyID is defined as anIDENTITY(3,2) however, this is where we need to rely on the Stars luck for the INSERT to work. Why? Well 2 + (3*n) and 3+(2*n) can give very different numbers. The first are as you saw at the start of this answer. For the latter, we have numbers like 3, 5, 7, 9, 11. As you can see, only 1 in 3 of these numbers match a number in our original sequence, so luck is what we are going to be relying on.
Let's, therefore, try a single INSERT.
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(2,1);
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Sandbox", table "dbo.Gyartok", column 'GyID'.
Well, that didn't work, but it was expected. 3 isn't a value in the table Gyartok. Let's try again!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(2,2);
It worked! The stars Luck was our side, and the IDENTITY value was a value in the table Gyartok. Let's try a couple of rows this time!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,3),
(4,4);
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_FcsGyartjaGya1". The conflict occurred in database "Sandbox", table "dbo.Gyartok", column 'GyID'.
No!! Not again. :( That's because the stars didn't align; 7 and 9 aren't in the other table. But wait, 11 was in the sequence, so let's try that:
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,5);
Error, again?! No, it cannot be!!! :( Oh wait, I forgot, the stars were against us before, because that INSERT failed against Gyartok for the value of 11. I need to wait for 17!
--13 fails
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
GO
--15 fails
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
GO
--17 works!
INSERT INTO dbo.FcsGyartjaGya (CsID,Ar)
VALUES(4,6);
And now we have another row in our table.
So what is the problem? Your design. GyID is defined as an IDENTITY and a FOREIGN KEY; meaning you are at the "whims" of SQL Server generating a value valid. This is not what you want. Just don't define the column as an IDENTITY and then INSERT the data with all 3 of your columns defined:
CREATE TABLE FcsGyartjaGya (
GyID int,-- IDENTITY(3, 2),
CsID INT,
Ar INT,
CONSTRAINT FK_FcsGyartjaGya1 FOREIGN KEY (GyID) REFERENCES Gyartok(GyID),
CONSTRAINT FK_FcsGyartjaGya2 FOREIGN KEY (CsID) REFERENCES Focicsuka(CsID),
CONSTRAINT PK_FcsGyartjaGya PRIMARY KEY (GyID, CsID)
)
GO
INSERT INTO dbo.FcsGyartjaGya (GyID, CsID, Ar)
VALUES(2,2,1),
(2,4,2),
(5,4,3),
(8,2,4),
(8,4,5);
And all these rows insert fine.
I think there is a bit confusion, if I understand correctly what You're trying to do, then you have two tables each with their own id, which is based on an identity column, so you get new values in those for free.
Then you are trying to make a relation table with extra data.
Issue 1: You cannot have FcsGyartjaGya.GyID be identity if it refers to Gyartok.GyID because you will want to insert into it and not rely on an auto increment. If it doesn't refer to the same it should have another name or my head will possibly explode :))
Issue 2: When populating a relation table you need to insert it with what pairs you want, there is no way SQL server can know how it should match these identity pairs in the relation table
I think this is what people are aiming at in the comments, for example
to insert a relationship between row with Focicsuka.CsID = 1 to Gyartok.GyID 7 and adding Ar = 300 have to look like
INSERT INTO FCSGYARTJAGYA(GYID, CSID, AR)
VALUES(7, 1, 300)
Unless You've forgotten to mention that you want to put some value for each of some value or based on something which can be scripted, in other words unless You have logics to define the pairs and their values, relationship tables cannot have defaults on their foreign key fields.
I'm trying to set my sql scripts into a transaction to achieve atomicity with my database.
The table structure is (simplified):
CREATE TABLE foo (
id serial NOT NULL,
foo varchar(50) NOT NULL,
CONSTRAINT foo_pk PRIMARY KEY (id)
);
CREATE TABLE access (
id serial NOT NULL,
foo_id int NULL
CONSTRAINT access_pk PRIMARY KEY (id)
);
ALTER TABLE access ADD CONSTRAINT access_foo
FOREIGN KEY (foo_id)
REFERENCES foo (id)
ON DELETE CASCADE
ON UPDATE CASCADE
DEFERRABLE
INITIALLY DEFERRED;
In my code I first declare:
client.query('BEGIN'); (I'm using npm library 'pg') then
insert a row into a table 'foo', then another insert to 'access' with a foo_id from the first insert. After that there is client.query('COMMIT');
All of this is in a try catch, and in the catch is client.query('ROLLBACK'); and the rolling back seems to be working if there is an issue either of the inserts. When everything should be committed I still end up in the catch block for this:
message: "insert or update on table "access" violates foreign key constraint "access_foo""
detail: "Key (foo_id)=(20) is not present in table "foo"."
I thought that deferring constraint would be enough to do this, but I guess I'm wrong. Any help is welcome.
You probably have some issue with the transaction demarcation. I ran a simple test and works wells.
insert into foo (id, foo) values (1, 'Anne');
start transaction;
insert into access (id, foo_id) values (101, 1);
insert into access (id, foo_id) values (107, 7); -- 7 does not exist yet...
insert into foo (id, foo) values (7, 'Ivan'); -- 7 now exists!
commit; -- at this point all is good
See running example at DB Fiddle.
I am trying to remove a UNIQUE constraint on a column for sqlite but I do not have the name to remove the constraint. How can I find the name of the UNIQUE constraint name to remove it.
Below is the schema I see for the table I want to remove the constraint
UNIQUE (datasource_name)
sqlite> .schema datasources
CREATE TABLE "datasources" (
created_on DATETIME NOT NULL,
changed_on DATETIME NOT NULL,
id INTEGER NOT NULL,
datasource_name VARCHAR(255),
is_featured BOOLEAN,
is_hidden BOOLEAN,
description TEXT,
default_endpoint TEXT,
user_id INTEGER,
cluster_name VARCHAR(250),
created_by_fk INTEGER,
changed_by_fk INTEGER,
"offset" INTEGER,
cache_timeout INTEGER, perm VARCHAR(1000), filter_select_enabled BOOLEAN, params VARCHAR(1000),
PRIMARY KEY (id),
CHECK (is_featured IN (0, 1)),
CHECK (is_hidden IN (0, 1)),
FOREIGN KEY(created_by_fk) REFERENCES ab_user (id),
FOREIGN KEY(changed_by_fk) REFERENCES ab_user (id),
FOREIGN KEY(cluster_name) REFERENCES clusters (cluster_name),
UNIQUE (datasource_name),
FOREIGN KEY(user_id) REFERENCES ab_user (id)
);
SQLite only supports limited ALTER TABLE, so you can't remove the constaint using ALTER TABLE. What you can do to "drop" the column is to rename the table, create a new table with the same schema except for the UNIQUE constraint, and then insert all data into the new table. This procedure is documented in the Making Other Kinds Of Table Schema Changes section of ALTER TABLE documentation.
I just ran into this myself. An easy solution was using DB Browser for SQLite
It let me remove a unique constraint with just a checkbox in a gui.
PRAGMA foreign_keys=off;
BEGIN TRANSACTION;
ALTER TABLE table_name RENAME TO old_table;
CREATE TABLE table_name
(
column1 datatype [ NULL | NOT NULL ],
column2 datatype [ NULL | NOT NULL ],
...
);
INSERT INTO table_name SELECT * FROM old_table;
COMMIT;
PRAGMA foreign_keys=on;
Source: https://www.techonthenet.com/sqlite/unique.php
I was just working through this issue on a small database and found it easier to dump the data as SQL statements, it prints out your tables exactly as they are and also adds the INSERT INTO statements to rebuild the DB.
The .help terminal command shows:
.dump ?OBJECTS? Render database content as SQL
and prints the SQL to the terminal, you can update it in a TXT file. For once off changes and tidying this seems like a reasonable solution albeit a little inelegant
I'm new to SQL Server.
I want to reference the same table column as below,
CREATE TABLE JOIN_DEPARTMENTS
(
DEPTID INT PRIMARY KEY,
DEPTNAME VARCHAR(20)
);
CREATE TABLE JOIN_EMPLOYEES
(
EMPID INT PRIMARY KEY,
EMPNAME VARCHAR(20),
MGRID INT,
DEPTID INT FOREIGN KEY REFERENCES JOIN_DEPARTMENTS(DEPTID),
CONSTRAINT FK_SELFREFE FOREIGN KEY (MGRID) REFERENCES EMPLOYEES(EMPID) ON DELETE SET NULL
);
INSERT INTO JOIN_DEPARTMENTS VALUES (100, 'BFS');
INSERT INTO JOIN_DEPARTMENTS VALUES (101, 'MELT');
INSERT INTO JOIN_EMPLOYEES VALUES(1, 'SARA', NULL, 100); --> inserts fine
INSERT INTO JOIN_EMPLOYEES VALUES(2, 'SANTHOSH', 1, 100); -->
Throws the following error
Msg 547, Level 16, State 0, Line 530
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_SELFREFE". The conflict occurred in database "SARA", table "dbo.EMPLOYEES", column 'EMPID'.
What I am doing wrong, here?
Your constraint references EMPLOYEES but you are inserting into JOIN_EMPLOYEES - check EMPLOYEES to make sure an EMPID=1 exists, or modify your constraint to check JOIN_EMPLOYEES instead of EMPLOYEES
EDIT: In response to comment: I don't know how to make the self referencing ON DELETE SET NULL constraint work, but I think you could accomplish the same goal by creating an AFTER DELETE trigger that set MGRID to NULL in all rows where MGRID = EMPID of the deleted row(s). I can't fully test this, but I think this will work
CREATE TRIGGER trJOIN_EMPLOYEE_AfterDel ON JOIN_EMPLOYEES AFTER DELETE
AS BEGIN
SET NOCOUNT ON;
UPDATE JOIN_EMPLOYEES SET MGRID = NULL
WHERE MGRID IN (SELECT EMPID FROM deleted)
END
Basically what it does is after your delete has been processed, but before the transaction is considered complete, it goes back and also sets to NULL any MGRIDs that referenced the recently dropped employee ID.
Note that Microsoft has some relevant info
http://technet.microsoft.com/en-us/library/ms186973%28v=sql.105%29.aspx
says "The series of cascading referential actions triggered by a single DELETE or UPDATE must form a tree that contains no circular references." so I don't think you're going to get the self referential constraint to work.
Also note that you might have to remove some or all of the constraints before it will let you create that trigger, I think it's just INSTEAD OF DELETE triggers that conflict, but there is a chance AFTER DELETE triggers might conflict with some constraints - again, not enough experience here for me to be certain, try it and see.
I have a foreign key constraint between tables Sessions and Users. Specifically, Sessions.UID = Users.ID. Sometimes, I want Sessions.UID to be null. Can this be allowed? Any time I try to do this, I get an FK Constraint Violation.
Specifically, I'm inserting a row into Sessions via LINQ. I set the Session.User = null; and I get this error:
An attempt was made to remove a relationship between a User and a Session. However, one of the relationship's foreign keys (Session.UID) cannot be set to null.
However, when I remove the line that nulls the User property, I get this error on my SubmitChanges line:
Value cannot be null.
Parameter name: cons
None of my tables have a field called 'cons', nor is it in my 5,500-line DataContext.designer.cs file, nor is it in the QuickWatch for any of the related objects, so I have no idea what 'cons' is.
In the Database, Session.UID is a nullable int field and User.ID is a non-nullable int. I want to record sessions that may or may not have a UID, and I'd rather do it without disabling constraint on that FK relationship. Is there a way to do this?
I seemed to remember creating a nullable FK before, so I whipped up a quick test. As you can see below, it is definitely doable (tested on MSSQL 2005).
Script the relevant parts of your tables and constraints and post them so we can troubleshoot further.
CREATE DATABASE [NullableFKTest]
GO
USE [NullableFKTest]
GO
CREATE TABLE OneTable
(
OneId [int] NOT NULL,
CONSTRAINT [PK_OneTable] PRIMARY KEY CLUSTERED
(
[OneId] ASC
)
)
CREATE TABLE ManyTable (ManyId [int] IDENTITY(1,1) NOT NULL, OneId [int] NULL)
GO
IF NOT EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_ManyTable_OneTable]') AND parent_object_id = OBJECT_ID(N'[dbo].[ManyTable]') )
ALTER TABLE [dbo].[ManyTable] WITH CHECK ADD CONSTRAINT [FK_ManyTable_OneTable] FOREIGN KEY([OneId])
REFERENCES [dbo].[OneTable] ([OneId])
GO
--let's get a value in here
insert into OneTable(OneId) values(1)
select* from OneTable
--let's try creating a valid relationship to the FK table OneTable
insert into ManyTable(OneId) values (1) --fine
--now, let's try NULL
insert into ManyTable(OneId) values (NULL) --also fine
--how about a non-existent OneTable entry?
insert into ManyTable(OneId) values (5) --BOOM! - FK violation
select* from ManyTable
--1, 1
--2, NULL
--cleanup
ALTER TABLE ManyTable DROP CONSTRAINT FK_ManyTable_OneTable
GO
drop TABLE OneTable
GO
drop TABLE ManyTable
GO
USE [Master]
GO
DROP DATABASE NullableFKTest