[database] Oracle (ORA-02270) : no matching unique or primary key for this column-list error

I have two tables, Table JOB and Table USER, here is the structure

 CREATE TABLE JOB
 (
   ID       NUMBER NOT NULL ,
   USERID   NUMBER,
   CONSTRAINT B_PK PRIMARY KEY ( ID ) ENABLE
 );

 CREATE TABLE USER
 (
   ID       NUMBER NOT NULL ,
   CONSTRAINT U_PK PRIMARY KEY ( ID ) ENABLE
 );

Now, i want to add foreign key constraint to JOB referencing to USER table, as

Alter Table JOB ADD CONSTRAINT FK_USERID FOREIGN KEY(USERID) REFERENCES USER(ID);

this throws Oracle (ORA-02270) : no matching unique or primary key for this column-list error, doing some investigation it appears that we need to have either unique key or primary key constraint on USERID but I cannot have that as one USERID can have multiple JOBS associated with him, any thoughts or suggestions on how to fix this issue?

Researched ORA-02270 and SO related question

The data type in the Job table (Varchar2(20)) does not match the data type in the USER table (NUMBER NOT NULL).

The scheme is correct, User.ID must be the primary key of User, Job.ID should be the primary key of Job and Job.UserID should be a foreign key to User.ID. Also, your commands appear to be syntactically correct.

So what could be wrong? I believe you have at least a Job.UserID which doesn't have a pair in User.ID. For instance, if all values of User.ID are: 1,2,3,4,6,7,8 and you have a value of Job.UserID of 5 (which is not among 1,2,3,4,6,7,8, which are the possible values of UserID), you will not be able to create your foreign key constraint. Solution:

delete from Job where UserID in (select distinct User.ID from User);

will delete all jobs with nonexistent users. You might want to migrate these to a copy of this table which will contain archive data.

In my case the problem was cause by a disabled PK.

In order to enable it:

1. I look for the Constraint name with:

   SELECT * FROM USER_CONS_COLUMNS WHERE TABLE_NAME = 'referenced_table_name';

2. Then I took the Constraint name in order to enable it with the following command:

   ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;

Most Probably when you have a missing Primary key is not defined from parent table. then It occurs.

Like Add the primary key define in parent as below:

ALTER TABLE "FE_PRODUCT" ADD CONSTRAINT "FE_PRODUCT_PK" PRIMARY KEY ("ID") ENABLE;

Hope this will work.

create table articles(code varchar2(30)constraint articles_pk primary key,titre varchar2(30),
support varchar2(30) constraint support_fk references supports(support),type_support varchar2(30),
numeroDePage varchar2(30),datepublication date,categorie varchar2(30)constraint categorie_fk references organismes(categorie),
tendance varchar2(30)constraint tendance_fk references apreciations(tendance));

Isn't the difference between your declaration of USERID the problem

JOB: UserID is Varchar
USER: UserID is Number?

I faced the same issue in my scenario as follow:

I created textbook table first with

create table textbook(txtbk_isbn varchar2(13)
primary key,txtbk_title varchar2(40),
txtbk_author varchar2(40) );

Then chapter table:

create table chapter(txtbk_isbn varchar2(13),chapter_title varchar2(40), constraint pk_chapter primary key(txtbk_isbn,chapter_title), constraint chapter_txtbook foreign key (txtbk_isbn) references textbook (txtbk_isbn));

Then topic table:

create table topic(topic_id varchar2(20) primary key,topic_name varchar2(40));

Now when I wanted to create a relationship called chapter_topic between chapter (having composite primary key) and topic (having single column primary key), I faced issue with following query:

create table chapter_topic(txtbk_isbn varchar2(13),chapter_title varchar2(40),topic_id varchar2(20), primary key (txtbk_isbn, chapter_title, topic_id), foreign key (txtbk_isbn) references textbook(txtbk_isbn), foreign key (chapter_title) references chapter(chapter_title), foreign key (topic_id) references topic (topic_id));

The solution was to refer to composite foreign key as below:

create table chapter_topic(txtbk_isbn varchar2(13),chapter_title varchar2(40),topic_id varchar2(20), primary key (txtbk_isbn, chapter_title, topic_id), foreign key (txtbk_isbn, chapter_title) references chapter(txtbk_isbn, chapter_title), foreign key (topic_id) references topic (topic_id));

Thanks to APC post in which he mentioned in his post a statement that:

Common reasons for this are
- the parent lacks a constraint altogether
- the parent table's constraint is a compound key and we haven't referenced all the columns in the foreign key statement.
- the referenced PK constraint exists but is DISABLED

We have following script for create new table:

CREATE TABLE new_table
(
id                     NUMBER(32) PRIMARY KEY,
referenced_table_id    NUMBER(32)    NOT NULL,
CONSTRAINT fk_new_table_referenced_table_id
    FOREIGN KEY (referenced_table_id)
        REFERENCES referenced_table (id)
);

and we were getting this error on execute:

[42000][2270] ORA-02270: no matching unique or primary key for this column-list

The issue was due to disabled primary key of referenced table in our case. We have enabled it by

ALTER TABLE referenced_table ENABLE PRIMARY KEY USING INDEX;

after that we created new table using first script without any issues

When running this command:

ALTER TABLE MYTABLENAME MODIFY CONSTRAINT MYCONSTRAINTNAME_FK ENABLE;

I got this error:

ORA-02270: no matching unique or primary key for this column-list
02270. 00000 -  "no matching unique or primary key for this column-list"
*Cause:    A REFERENCES clause in a CREATE/ALTER TABLE statement
          gives a column-list for which there is no matching unique or primary
          key constraint in the referenced table.
*Action:   Find the correct column names using the ALL_CONS_COLUMNS

The referenced table has a primary key constraint with matching type. The root cause of this error, in my case, was that the primary key constraint was disabled.

If primary key is not already defined on parent table then this issue may arise. Please try to define the primary key on existing table. For eg:

ALTER TABLE table_name
ADD PRIMARY KEY (the_column_which_is_primary_key);