when I try to insert in the database I get the following error:
DBD::mysql::st execute failed: Cannot add or update a child row: a foreign key constraint fails (`vym`.`vendedor`, CONSTRAINT `fk_vendedor_division` FOREIGN KEY (`codigo_empresa`, `codigo_division`) REFERENCES `division` (`codigo_empresa`, `codigo`)) at vendedores_aes_insert_85 line 53
I know I have a constraint but I don't know how to interpret the message. What is the constraint and why?
It looks like the division column is violating it. I would check the definition of the `fk_vendedor_division constraint.
Basically, the error is saying that you are trying to use a division in the vendedor table that doesnt exist in the other one.
The constraint is the foreign key on table vym.vendedor; columns codigo_empresa, codigo_division) are referencing table division columns (codigo_empresa, codigo).
Related
I have a table named "countries" and another table named "country_continents" in my DB. I want to make my continent_id column in countries , a foreign key referencing the id of country_continents, but I am getting an error message. This is the SQL to create the foreign key and the error:
ALTER TABLE countries
ADD CONSTRAINT fk_continent_id
FOREIGN KEY (continent_id)
REFERENCES country_continents(id);
ERROR:
#1215 - cannot add foreign key constraint
At first, I was getting the :
"Error: relational features are disabled"
so I ran the command ALTER TABLE countries ENGINE=InnoDB; and ALTER TABLE country_continents ENGINE=InnoDB; but now I'm getting the #1215 error.
This is the Structure for "country_continents":
This is the Structure for "countries":
Any ideas on whats happening? Thanks in advance.
I think the error is due to:
in your countries table, continent_id is not unsigned.
Edit that and tell me if it worked
I have successfully added my first FK in heidisql using the foreign key tab and adding all the appropriate sections.
I have tried to do the same to my second related column both by using the FK tab and by running a query but I keep getting an error.
SQL Error (1005): Can't create table sprout.#sql-430_3 (errno: 150 "Foreign key constraint is incorrectly formed")
sprout is my db name so I have no idea why it is saying cant create table sprout (because I'm not referencing it in my query).
sql query for my first FK(generated via heidisql):
ALTER TABLE `purchase_history`
ADD CONSTRAINT `bus_id` FOREIGN KEY (`bus_id`) REFERENCES `business` (`bus_id`);
sql query for my second FK(generated via heidisql)
ALTER TABLE `purchase_history`
ADD CONSTRAINT `bus_name_fk` FOREIGN KEY (`bus_name`) REFERENCES `business` (`bus_name`);
sql query I wrote to try and add second FK
Alter table purchase_history
Add constraint bus_name_fk
Foreign key (bus_name)
references business(bus_name);
Can someone help explain to me how my constraint is incorrectly formed? To my understanding I was able to add another constraint to the the table.
This is too long for a comment.
Huh? Why are you adding two foreign constraints to the same table . . . but using different columns? That doesn't really make sense. In general, the foreign key should be referencing the primary key of the other table, which I presume is bus_id.
Then, if you want the business name, you can use a join to get the name.
I am facing the error while executing insert or update operation in mysql. I have already define the relation between two tables still it throws error
Error Code: 1452. Cannot add or update a child row:
a foreign key constraint fails ('test'.'system_review', CONSTRAINT 'system_review_ibfk_1' FOREIGN KEY ('SYS_USER_ID') REFERENCES 'user_details' ('USER_ID'))
Possibly you have set Relationship between your two tables. And you are trying to update base record id, which is used by your child table.
I am trying to set up a foreign key in Mysql workbench. I used the same name for the foreign key as the primary key of the table I am trying to set a relationship with. I already have one relation set up this way in another table, but When I try and apply the alterations to this table, the script gives me an error:
Error 1005: Can't create table 'X.#sql-718_a' (errno: 121)
SQL Statement:
ALTER TABLE `X`.`X_use`
ADD CONSTRAINT `XyzID`
FOREIGN KEY (`XyzID` ) REFERENCES `X`.`Xyz` (`XyzID` )
ON DELETE NO ACTION O
N UPDATE NO ACTION ,
ADD INDEX `XyzID` (`XyzID` ASC) ,
However, if I change the foreign key name to "AbcID" I have no problem setting up the foreign key relation. Why is that and why can't I have the primary key name from one table be the same for the foreign key for this table? I have set up relations like that previously but for this table I cannot.
Constraint names have to be unique within the database.
That (errno: 121) in the error message means that MySQL encountered a duplicate key exception. The usual cause of this is that there is already a constraint of the same name in the database.
This "unique name" requirement is one reason why the normative pattern is to include the table name when constructing the name of the foreign key constraint. e.g. FK_table_cols e.g. FK_X_use_XyzID.
Why must the constraint name be unique within the database? That's a question for the dbms designers.
But consider this: when the database encounters a constraint violation, it throws an error that contains the name of the constraint. When that constraint name references only one constraint in the database, that makes locating the problem a bit easier.
You can not use same constrain name through out the database as described in ACID properties of DB.
If i do the first one i have no problem. When i do addition i get a syntax error. What is wrong with the syntax? The error says syntax error near [entire 2nd line]
alter table `ban_Status` add FOREIGN KEY (`banned_user`) REFERENCES `user_data`(`id`)
alter table `ban_Status` add FOREIGN KEY (`banned_user`) REFERENCES `user_data`(`id`),
FOREIGN KEY (`banning_user`) REFERENCES `user_data`(`id`),
FOREIGN KEY (`unban_user`) REFERENCES `user_data`(`id`)
I think you need "add" before lines 2 and 3. That or you need to name your constraints.