I want to change primary key of table, initially it was id, now i want to change it to userid
smsusers(id,fname,lname,userid)
Here id is varchar type
adn userid is int type
for this i am trying following query
ALTER TABLE smsusers DROP PRIMARY KEY
which is showing this error
#1025 - Error on rename of '.\xrcwrn_sms\#sql-ae0_6f' to
'.\xrcwrn_sms\smsusers' (errno: 150)
id of smsusers is associated with many tables as foreign key.
How to change the primary key.
Here is an example:
ALTER TABLE `database`.`table`
DROP PRIMARY KEY,
ADD PRIMARY KEY (`userid`);
The message is telling you that you can't drop the primary key yet because it is referenced by one or more foreign keys. You need to identify and drop the foreign keys first, then drop the primary key.
ERROR NO:150 means Foreign key definition problem. I think that some other table has a foreign key constraint depending on this PK, so you need to drop that first and rebuild it later.
I tried this link. This is working properly.
My steps are
CREATE INDEX id_pk_unique ON smsusers (id)
ALTER TABLE parent DROP PRIMARY KEY;
ALTER TABLE parent ADD PRIMARY KEY (userid);
Related
I have a table with a primary key. I want to add a new column and make that one the primary key. However, I can't drop the primary key constraint on the old column, because it is referenced as a foreign key in another table.
So I dropped the foreign key constraint and the index:
ALTER TABLE experiments DROP FOREIGN KEY experiments_ibfk_1
ALTER TABLE experiments DROP INDEX `analysisfk`;
I checked with show create that both constraint and index are gone. Then I tried to drop the primary key again with
ALTER TABLE analysis DROP PRIMARY KEY;
However, I still got an Error 1025.
Am I overlooking something?
SOLVED: There was another key constraint which I overlooked because of a misleading name. Leaving this here anyway as it shows some useful stuff
I have a Mysql table having the following structure:
As you can see there is a composite primary key constraint between the fields: word_id and preposition_id.
I want to remove the Primary Key constraint from word_id without touching the preposition_id field, and without losing data from the linked tables (Foreign Key tables). How can I do it?
Regards.
There is no syntax available to modify a constraint and drop only "a half" of the primary key.
You must drop the whole primary key, and then recreate it from scrach.
Just:
ALTER TABLE tablename DROP PRIMARY KEY;
and then:
ALTER TABLE tablename ADD PRIMARY KEY ( preposition_id );
You need first to drop all foreign keys thar reference the primary key in this table.
Data in tables will be preserved.
I need to add a primary key on a table "usernames"
I have 3 columns in it :
userid int(10)
username char(20)
user char(50)
and the primary key is set on 'username' field and i used it as a foreign key to link it to another table. Now i need to add primary key on 'userid' field also... so i tried out :
alter table `usernames` drop primary key, add primary key(userid,username);
and i get an error saying
ERROR 1553 (HY000): Cannot drop index 'PRIMARY":needed in a foreign key constraint
is there any possible way to do this ??
There is:
Drop the FK constraint
Drop PK Constraint
Create New PK
Add Unique Constraint on the name column
Recreate FK
Raj
I assume you use MySql (despite you tag your question as Sql Server).
You can decide to:
Disable all check and try to remove primary key but the new must have the same name
or
Drop foreign key constraints referred to your primary key and then remove your primary key and finally re-add foreign keys
You have to drop the foreign key in order to modify the primary key
As implied by the name, a table can only have at most one PRIMARY key. Whilst it can have other UNIQUE keys, which have a similar effect, they really ought not be used for foreign-key relations.
So, you have two choices:
Retain your existing schema (perhaps username is a perfectly good natural key such that you need not bother with a synthetic one, in which case you can consider dropping the userid column altogether); or
Making userid your PRIMARY key, in which case username should not be used for foreign key relations. I outline below a method for doing this "offline" (where the database is guaranteed not to be altered by any other process during the transition); should you be working "online", you will need to add further steps to ensure integrity is preserved:
Add a new userid column for the foreign key in all child tables and drop the existing foreign key constraint:
ALTER TABLE foo
ADD COLUMN userid INT(10),
DROP FOREIGN KEY fk_name;
Change the primary key in your usernames tables (should you wish for the database to enforce a uniqueness constraint over username, you can define a UNIQUE key instead):
ALTER TABLE usernames
DROP PRIMARY KEY,
ADD PRIMARY KEY (userid),
ADD UNIQUE KEY (username); -- optional
Update the child tables to contain the relevant userid from the parent:
UPDATE foo JOIN usernames USING (username)
SET foo.userid = usernames.userid;
Add the new foreign key constraints and drop the old username columns from the child tables:
ALTER TABLE foo
ADD FOREIGN KEY (userid) REFERENCES usernames (userid),
DROP COLUMN username;
I've got problem with dropping foreign key index, I always get the same error
ALTER TABLE `comments` DROP INDEX `id_user`
which outputs
1025 - Error on rename of './postuj_cz1/#sql-d834_a0c704'
to './postuj_cz1/comments' (errno: 150)
The id_user on the other table is simple primary key index.
I'm using MySQL version 5.0.85
There are other causes too. For example I had a unique index involving two separate foreign key columns. I had to drop the foreign keys in question before I could drop the unique index. (And obviously you can add the foreign keys back afterward.)
INNODB : this could be as simple as removing the Relation before dropping the Index.
According to this link, the error relates to the definition of the primary key field. The error isn't about the foreign key index.
Check the primary key for the COMMENTS table to make sure it does not have the UNSIGNED keyword while the COMMENTS.id_user foreign key had the UNSIGNED keyword. This keyword was causing the problem - inconsistent type of field.
To fix, add the UNSIGNED keyword to the primary key definition for the COMMENTS table. Or remove the UNSIGNED keyword from the foreign key definition...
The index is for an foreign key on 'user' table, so
In first, try this command:
SHOW CREATE TABLE my_table
Find the name of the constraint corresponding to the index on the foreign key,
and after that, try the command:
ALTER TABLE my_table DROP FOREIGN KEY FK_myconstraintcode
WARNING: If you try to drop the foreign key with the foreign key name, you will have an error to!
I have a table whose primary key is used in several other tables and has several foreign keys to other tables.
CREATE TABLE location (
locationID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
...
) ENGINE = InnoDB;
CREATE TABLE assignment (
assignmentID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
locationID INT NOT NULL,
FOREIGN KEY locationIDX (locationID) REFERENCES location (locationID)
...
) ENGINE = InnoDB;
CREATE TABLE assignmentStuff (
...
assignmentID INT NOT NULL,
FOREIGN KEY assignmentIDX (assignmentID) REFERENCES assignment (assignmentID)
) ENGINE = InnoDB;
The problem is that when I'm trying to drop one of the foreign key columns (ie locationIDX) it gives me an error.
"ERROR 1025 (HY000): Error on rename"
How can I drop the column in the assignment table above without getting this error?
As explained here, seems the foreign key constraint has to be dropped by constraint name and not the index name.
The syntax is:
ALTER TABLE footable DROP FOREIGN KEY fooconstraint;
The foreign keys are there to ensure data integrity, so you can't drop a column as long as it's part of a foreign key. You need to drop the key first.
I would think the following query would do it:
ALTER TABLE assignmentStuff DROP FOREIGN KEY assignmentIDX;
As everyone said above, you can easily delete a FK. However, I just noticed that it can be necessary to drop the KEY itself at some point. If you have any error message to create another index like the last one, I mean with the same name, it would be useful dropping everything related to that index.
ALTER TABLE your_table_with_fk
drop FOREIGN KEY name_of_your_fk_from_show_create_table_command_result,
drop KEY the_same_name_as_above
Check what's the CONSTRAINT name and the FOREIGN KEY name:
SHOW CREATE TABLE table_name;
Remove both the CONSTRAINT name and the FOREIGN KEY name:
ALTER TABLE table_name
DROP FOREIGN KEY the_name_after_CONSTRAINT,
DROP KEY the_name_after_FOREIGN_KEY;
Hope this helps!
Hey I followed some sequence above,
and found some solution.
SHOW CREATE TABLE footable;
You will get FK Constrain Name like
ProjectsInfo_ibfk_1
Now you need to remove this constraints. by alter table commantd
alter table ProjectsInfo drop foreign key ProjectsInfo_ibfk_1;
Then drop the table column,
alter table ProjectsInfo drop column clientId;
Here's a way to drop foreign key constraint, it will work.
ALTER TABLE location.location_id
DROP FOREIGN KEY location_ibfk_1;
You usually get this error if your tables use the InnoDB engine. In that case you would have to drop the foreign key, and then do the alter table and drop the column.
But the tricky part is that you can't drop the foreign key using the column name, but instead you would have to find the name used to index it. To find that, issue the following select:
SHOW CREATE TABLE region;
This should show you a row ,at left upper corner click the +option ,the click the full text raio button then click the go .there you will get the name of the index, something like this:
CONSTRAINT region_ibfk_1 FOREIGN KEY (country_id) REFERENCES country (id) ON DELETE NO ACTION ON UPDATE NO ACTION
Now simply issue an:
alter table region drop foreign key region_ibfk_1;
or
more simply just type:-
alter table TableName drop foreign key TableName_ibfk_1;
remember the only thing is to add _ibfk_1 after your tablename to make like this:- TableName_ibfk_1
first need to get actual constrain name by this query
SHOW CREATE TABLE TABLE_NAME
This query will result constrain name of the foreign key, now below query will drop it.
ALTER TABLE TABLE_NAME DROP FOREIGN KEY COLUMN_NAME_ibfk_1
last number in above constrain name depends how many foreign keys you have in table
You can not drop the foreign key column because it is being referenced from the table assignmentStuff. So you should first drop the foreign key constraint assignmentStuff.assignmentIDX.
A similar question has already been asked here. Check also here for more info.
Try this:
alter table Documents drop
FK__Documents__Custo__2A4B4B5E
step1: show create table vendor_locations;
step2: ALTER TABLE vendor_locations drop foreign key vendor_locations_ibfk_1;
it worked for me.