I have two tables. On is a table that contains IP Ranges and their respective country attributions (IPGEO table). The other is a table which simply keeps track of the last country the site was accessed from on a per user basis. The idea is that, if the user suddenly accesses the site from another country, I notify the user about this via email.
Now for the actual tables. I have these two:
The IPGeo table that contains the IP ranges
CREATE TABLE IF NOT EXISTS `politiker_lu`.`IPGeo` (
`IPFrom` INT(11) NOT NULL ,
`IPTo` INT(11) NOT NULL ,
`code2` VARCHAR(2) NOT NULL ,
`code3` VARCHAR(3) NOT NULL ,
`Country` VARCHAR(45) NOT NULL ,
INDEX `index1` (`IPFrom` ASC) ,
INDEX `index2` (`IPTo` ASC) )
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
Then, there is the user_geo table that tracks the last country from which the user accessed the site.
CREATE TABLE IF NOT EXISTS `politiker_lu`.`user_geo` (
`fi_user` INT(10) UNSIGNED NOT NULL ,
`fi_country` VARCHAR(3) NOT NULL ,
`timestamp` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ,
PRIMARY KEY (`fi_user`) ,
INDEX `fk_user_geo_1` (`fi_user` ASC) ,
CONSTRAINT `fk_user_geo_1`
FOREIGN KEY (`fi_user` )
REFERENCES `politiker_lu`.`user` (`id_user` )
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
These are the tables as they exist. I now want to reference these two tables as follows:
ALTER TABLE `politiker_lu`.`user_geo`
ADD CONSTRAINT `fk_user_geo_IPGeo1`
FOREIGN KEY (`fi_country` )
REFERENCES `politiker_lu`.`IPGeo` (`code3` )
ON DELETE CASCADE
ON UPDATE CASCADE
, ADD INDEX `fk_user_geo_IPGeo1` (`fi_country` ASC) ;
That Statement however fails with errno 150. Both tables are utf8, both columns have the same data-type. Am I missing something vital here?
Notes
The table user exists and has all the references and is actually irrelevant to the problem. I left it so that I didn't need to edit the statement too much.
You need to add a unique index or a primary key on the IPGeo.code3 column in order to reference it with a foreign key.
You can see the error by running show engine innodb status\G and looking under the LATEST FOREIGN KEY ERROR section. The error probably looks something like this:
Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.
Note that the internal storage type of ENUM and SET changed in
tables created with >= InnoDB-4.1.12, and such columns in old tables
cannot be referenced by such columns in new tables.
See http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html
for correct foreign key definition.
Related
When I execute the follow two queries (I have stripped them down to absolutely necessary):
mysql> CREATE TABLE foo(id INT PRIMARY KEY);
Query OK, 0 rows affected (0.01 sec)
mysql> CREATE TABLE bar ( id INT, ref INT, FOREIGN KEY (ref) REFERENCES foo(id)) ENGINE InnoDB;
I get the following error:
ERROR 1005 (HY000): Can't create table './test/bar.frm' (errno: 150)
Where the **** is my error? I haven't found him while staring at this for half an hour.
From FOREIGN KEY Constraints
If you re-create a table that was
dropped, it must have a definition
that conforms to the foreign key
constraints referencing it. It must
have the right column names and types,
and it must have indexes on the
referenced keys, as stated earlier. If
these are not satisfied, MySQL returns
error number 1005 and refers to error
150 in the error message.
My suspicion is that it's because you didn't create foo as InnoDB, as everything else looks OK.
Edit: from the same page -
Both tables must be InnoDB tables and they must not be TEMPORARY tables.
You can use the command SHOW ENGINE INNODB STATUS to get more specific information about the error.
It will give you a result with a Status column containing a lot of text.
Look for the section called LATEST FOREIGN KEY ERROR which could for example look like this:
------------------------
LATEST FOREIGN KEY ERROR
------------------------
190215 11:51:26 Error in foreign key constraint of table `mydb1`.`contacts`:
Create table `mydb1`.`contacts` with foreign key constraint failed. You have defined a SET NULL condition but column 'domain_id' is defined as NOT NULL in ' FOREIGN KEY (domain_id) REFERENCES domains (id) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT contacts_teams_id_fk FOREIGN KEY (team_id) REFERENCES teams (id) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT' near ' ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT contacts_teams_id_fk FOREIGN KEY (team_id) REFERENCES teams (id) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT'.
To create a foreign key ,
both the main column and the reference column must have same definition.
both tables engine must be InnoDB.
You can alter the engine of table using this command , please take the backup before executing this command.
alter table [table name] ENGINE=InnoDB;
I had the same problem, for those who are having this also:
check the table name of the referenced table
I had forgotten the 's' at the end of my table name
eg table Client --> Clients
:)
Apart form many other reasons to end up with MySql Error 150 (while using InnoDB), One of the probable reason, is the undefined KEY in the create statement of the table containing the column name referenced as a foreign key in the relative table.
Let's say the create statement of master table is -
CREATE TABLE 'master_table' (
'id' int(10) NOT NULL AUTO_INCREMENT,
'record_id' char(10) NOT NULL,
'name' varchar(50) NOT NULL DEFAULT '',
'address' varchar(200) NOT NULL DEFAULT '',
PRIMARY KEY ('id')
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
and the create syntax for the relative_table table where the foreign key constraint is set from primary table -
CREATE TABLE 'relative_table' (
'id' int(10) NOT NULL AUTO_INCREMENT,
'salary' int(10) NOT NULL DEFAULT '',
'grade' char(2) NOT NULL DEFAULT '',
'record_id' char(10) DEFAULT NULL,
PRIMARY KEY ('id'),
CONSTRAINT 'fk_slave_master' FOREIGN KEY ('record_id') REFERENCES 'master' ('record_id')
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
This script is definitely going to end with MySql Error 150 if using InnoDB.
To solve this, we need to add a KEY for the The column record_id in the master_table table and then reference in the relative_table table to be used as a foreign_key.
Finally, the create statement for the master_table, will be -
CREATE TABLE 'master_table' (
'id' int(10) NOT NULL AUTO_INCREMENT,
'record_id' char(10) NOT NULL,
'name' varchar(50) NOT NULL DEFAULT '',
'address' varchar(200) NOT NULL DEFAULT '',
PRIMARY KEY ('id'),
KEY 'record_id' ('record_id')
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
I had very same problem and the reason was the "collation" of columns was different. One was latin1 while the other was utf8
This may also happen if you have not given correct column name after "references" keyword.
I'm having issues with setting up a relation between 2 tables called Customer and Customer_Number. I have both tables set to InnoDB both have indexes, but when I go to create the foreign key, I get a "no index defined" error. Below are some screen shots
Here Is the Customer table.
Here is the Customer_Number table.
And here is my error message when trying to create the foreign key.
And lastly, this is the error I get when trying to create the relationship manually.
I just can't seem to figure out the issue, and it's driving me nuts!
the output for SHOW CREATE TABLE Customer is
CREATE TABLE `Customer` (
`Customer_ID` int(11) NOT NULL AUTO_INCREMENT,
`First` varchar(255) NOT NULL,
`Last` varchar(255) NOT NULL,
PRIMARY KEY (`Customer_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1
and the output for SHOW CREATE TABLE Customer_Number is
CREATE TABLE `Customer_Number` (
`Num_ID` int(11) NOT NULL AUTO_INCREMENT,
`Customer_ID` int(11) NOT NULL,
`Number` varchar(255) NOT NULL,
PRIMARY KEY (`Num_ID`),
KEY `Customer_ID` (`Customer_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1
The two CREATE TABLE statements as posted are correct and should be able to accept a new FOREIGN KEY constraint on Customer_Number.Customer_ID since the necessary criteria are met (same data type as referenced column, comparable index or primary key on referenced column).
An ALTER statement succeeds in my testing:
ALTER TABLE Customer_Number ADD FOREIGN KEY (Customer_ID) REFERENCES Customer (Customer_ID);
Being unfamiliar with how PhpMyAdmin abstracts some RDBMS errors, it is hard to say for sure what exactly has gone wrong in the GUI. But if you run the ALTER statement manually and encounter errors about failed foreign key constraints, that's an indication the referencing table already contains values in the column which do not reference a valid row value in the parent table. To uncover those rows so you can address them, execute a query like:
SELECT * FROM Customer_Number WHERE Customer_ID NOT IN (SELECT Customer_ID FROM Customer)
Once you have found the problematic rows, you can either delete them (if unneeded) or update their values to the value of a valid row value in the referenced table. If the column's definition allowed NULL (which yours does not) you could also UPDATE them to set them NULL then run the ALTER statement again.
It is also possible to disable foreign key checks temporarily, add the constraint, update the rows to match valid parent table values, the reenable foreign key checks.
please try this.
alter table Customer_Number add foreign key(customer_ID) references Customer (Customer_ID);
-- Table Project_DB.Product_table
CREATE TABLE IF NOT EXISTS `Project_DB`.`Product_table`
(
`Product_id` INT UNSIGNED NOT NULL AUTO_INCREMENT ,
`User_id_fk` INT UNSIGNED NOT NULL ,
`Product_Category_id` INT UNSIGNED NOT NULL ,
`Product_Name` VARCHAR( 45 ) NOT NULL ,
`Product_Price` INT UNSIGNED NOT NULL ,
`Product_details` MEDIUMTEXT NULL ,
PRIMARY KEY ( `Product_id` ) ,
INDEX `User_id_idx` ( `User_id_fk` ASC ) ,
CONSTRAINT `User_id` FOREIGN KEY ( `User_id_fk` )
REFERENCES `Project_DB`.`Registration_table` ( `User_id` )
ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE = INNODB;
MySQL said: Documentation
#1022 - Can't write; duplicate key in table 'product_table'
The Database Schema Cannot have two or more FOREIGN KEY with same name. I change all FOREIGN KEYS to different names in my DB Schema then it works...
I recommend you try removing the line
INDEX `User_id_idx` ( `User_id_fk` ASC ) ,
Either that, or remove the foreign key constraint from the table definition, and add that in a separate ALTER TABLE statement.
InnoDB automatically creates the required index when a foreign key constraint is added, or uses a suitable index if it's already there.
I believe the error is occurring because InnoDB is attempting to create an index for the foreign key, rather than using the index that was defined previously. That is, when the CREATE TABLE statement (as posted by OP) is processed, InnoDB is attempting to create both the index defined on User_id_fk, and the index required for the foreign key.
And those two indexes are "duplicates" of each other.
The workaround is to modify the CREATE TABLE statement, to avoid InnoDB attempting to create "duplicate" indexes.
I had the same problem, MySQLWorkbench was working fine when I forward engineered a build script and then it decided to throw it's toys out of the pram.
I fixed the problem by dropping my database in phpMyAdmin and then ran the script again from MySQLWorkbench and it worked. I suspect I'd changed something that caused a conflict.
I know this is an extreme measure; others have said, to go through the DB schema and find duplicates.
Usually, you already use that constraint in another table that you also use for foreign key.
I'm creating a few simple tables and I can't get passed this foreign key error and I'm not sure why. Here's the script below.
create TABLE Instructors (
ID varchar(10),
First_Name varchar(50) NOT NULL,
Last_Name varchar(50) NOT NULL,
PRIMARY KEY (ID)
);
create table Courses (
Course_Code varchar(10),
Title varchar(50) NOT NULL,
PRIMARY KEY (Course_Code)
);
create table Sections (
Index_No int,
Course_Code varchar(10),
Instructor_ID varchar(10),
PRIMARY KEY (Index_No),
FOREIGN KEY (Course_Code) REFERENCES Courses(Course_Code)
ON DELETE cascade
ON UPDATE cascade,
FOREIGN KEY (Instructor_ID) REFERENCES Instructors(ID)
ON DELETE set default
);
Error Code: 1005. Can't create table '336_project.sections' (errno: 150)
My data types seem identical and the syntax seems correct. Can anyone point out what I'm not seeing here?
I'm using MySQL Workbench 5.2
This error also occurs if you are relating columns of different types, eg. int in the source table and BigInt in the destination table.
If you're using the InnoDB engine, the ON DELETE SET DEFAULT is your problem. Here's an excerpt from the manual:
While SET DEFAULT is allowed by the MySQL Server, it is rejected as invalid by InnoDB. CREATE TABLE and ALTER TABLE statements using this clause are not allowed for InnoDB tables.
You can use ON DELETE CASCADE or ON DELETE SET NULL, but not ON DELETE SET DEFAULT. There's more information here.
You can run
SHOW ENGINE INNODB STATUS
to read the reason of the failure in a human readable format
e.g.
------------------------
LATEST FOREIGN KEY ERROR
------------------------
150331 15:51:01 Error in foreign key constraint of table foobar/#sql-413_81:
FOREIGN KEY (`user_id`) REFERENCES `foobar`.`users`(`id`) ON DELETE SET NULL ON UPDATE CASCADE:
You have defined a SET NULL condition though some of the columns are defined as NOT NULL.
In order to create a FOREIGN KEY with reference to another table, the keys from both tables should be PRIMARY KEY and with the same datatype.
In your table sections, PRIMARY KEY is of different datatype i.e INT but in another table, it's of type i.e VARCHAR.
It may also be the case if you are not specifying the ON DELETE at all but are trying to reference a MYISAM table from InnoDB table:
CREATE TABLE `table1`(
`id` INT UNSIGNED NOT NULL,
`name` VARCHAR(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MYISAM CHARACTER SET UTF8;
CREATE TABLE `table2`(
`id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
`table1_id` INT UNSIGNED NOT NULL,
`some_value` VARCHAR(255) NOT NULL,
PRIMARY KEY (`id`),
KEY `fk_table1_id`(`table1_id`),
CONSTRAINT FOREIGN KEY (`table1_id`) REFERENCES `table1`(`id`)
) ENGINE=INNODB CHARACTER SET UTF8;
The above will throw errno 150. One need to change the first table to InnoDB too for this to work.
It is failing on the
ON DELETE set default
I have not come across that before and I am not seeing it in the manuals either ( but then it is late )
Update
just seen this in the manual
While SET DEFAULT is allowed by the MySQL Server, it is rejected as
invalid by InnoDB. CREATE TABLE and ALTER TABLE statements using this
clause are not allowed for InnoDB tables.
I guess you may be using InnoDB tables ?
For completeness sake - you will also get this error if you make a foreign reference to a table that isn't defined at the time;
Here Problem is in database engine ( table1 MYISAM and table2 ENGINE).
To set FOREIGN KEYs,
Both table must be in same ENGINE and same charset.
PK column in parent and FK column must be in same data type and same collation type.
Hope you got an idea.
Make sure that table type is InnoDB, MyISAM does not support foreign key, afaik.
I was working on creating some tables in database foo, but every time I end up with errno 150 regarding the foreign key. Firstly, here's my code for creating tables:
CREATE TABLE Clients
(
client_id CHAR(10) NOT NULL ,
client_name CHAR(50) NOT NULL ,
provisional_license_num CHAR(50) NOT NULL ,
client_address CHAR(50) NULL ,
client_city CHAR(50) NULL ,
client_county CHAR(50) NULL ,
client_zip CHAR(10) NULL ,
client_phone INT NULL ,
client_email CHAR(255) NULL ,
client_dob DATETIME NULL ,
test_attempts INT NULL
);
CREATE TABLE Applications
(
application_id CHAR(10) NOT NULL ,
office_id INT NOT NULL ,
client_id CHAR(10) NOT NULL ,
instructor_id CHAR(10) NOT NULL ,
car_id CHAR(10) NOT NULL ,
application_date DATETIME NULL
);
CREATE TABLE Instructors
(
instructor_id CHAR(10) NOT NULL ,
office_id INT NOT NULL ,
instructor_name CHAR(50) NOT NULL ,
instructor_address CHAR(50) NULL ,
instructor_city CHAR(50) NULL ,
instructor_county CHAR(50) NULL ,
instructor_zip CHAR(10) NULL ,
instructor_phone INT NULL ,
instructor_email CHAR(255) NULL ,
instructor_dob DATETIME NULL ,
lessons_given INT NULL
);
CREATE TABLE Cars
(
car_id CHAR(10) NOT NULL ,
office_id INT NOT NULL ,
engine_serial_num CHAR(10) NULL ,
registration_num CHAR(10) NULL ,
car_make CHAR(50) NULL ,
car_model CHAR(50) NULL
);
CREATE TABLE Offices
(
office_id INT NOT NULL ,
office_address CHAR(50) NULL ,
office_city CHAR(50) NULL ,
office_County CHAR(50) NULL ,
office_zip CHAR(10) NULL ,
office_phone INT NULL ,
office_email CHAR(255) NULL
);
CREATE TABLE Lessons
(
lesson_num INT NOT NULL ,
client_id CHAR(10) NOT NULL ,
date DATETIME NOT NULL ,
time DATETIME NOT NULL ,
milegage_used DECIMAL(5, 2) NULL ,
progress CHAR(50) NULL
);
CREATE TABLE DrivingTests
(
test_num INT NOT NULL ,
client_id CHAR(10) NOT NULL ,
test_date DATETIME NOT NULL ,
seat_num INT NOT NULL ,
score INT NULL ,
test_notes CHAR(255) NULL
);
ALTER TABLE Clients ADD PRIMARY KEY (client_id);
ALTER TABLE Applications ADD PRIMARY KEY (application_id);
ALTER TABLE Instructors ADD PRIMARY KEY (instructor_id);
ALTER TABLE Offices ADD PRIMARY KEY (office_id);
ALTER TABLE Lessons ADD PRIMARY KEY (lesson_num);
ALTER TABLE DrivingTests ADD PRIMARY KEY (test_num);
ALTER TABLE Applications ADD CONSTRAINT FK_Applications_Offices FOREIGN KEY (office_id) REFERENCES Offices (office_id);
ALTER TABLE Applications ADD CONSTRAINT FK_Applications_Clients FOREIGN KEY (client_id) REFERENCES Clients (client_id);
ALTER TABLE Applications ADD CONSTRAINT FK_Applications_Instructors FOREIGN KEY (instructor_id) REFERENCES Instructors (instructor_id);
ALTER TABLE Applications ADD CONSTRAINT FK_Applications_Cars FOREIGN KEY (car_id) REFERENCES Cars (car_id);
ALTER TABLE Lessons ADD CONSTRAINT FK_Lessons_Clients FOREIGN KEY (client_id) REFERENCES Clients (client_id);
ALTER TABLE Cars ADD CONSTRAINT FK_Cars_Offices FOREIGN KEY (office_id) REFERENCES Offices (office_id);
ALTER TABLE Clients ADD CONSTRAINT FK_DrivingTests_Clients FOREIGN KEY (client_id) REFERENCES Clients (client_id);
These are the errors that I get:
mysql> ALTER TABLE Applications ADD CONSTRAINT FK_Applications_Cars FOREIGN KEY
(car_id) REFERENCES Cars (car_id);
ERROR 1005 (HY000): Can't create table 'foo.#sql-12c_4' (errno: 150)
I ran SHOW ENGINE INNODB STATUS which gives a more detailed error description:
------------------------
LATEST FOREIGN KEY ERROR
------------------------
100509 20:59:49 Error in foreign key constraint of table foo/#sql-12c_4:
FOREIGN KEY (car_id) REFERENCES Cars (car_id):
Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.
Note that the internal storage type of ENUM and SET changed in
tables created with >= InnoDB-4.1.12, and such columns in old tables
cannot be referenced by such columns in new tables.
See http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html
for correct foreign key definition.
------------
I searched around on StackOverflow and elsewhere online - came across a helpful blog post here with pointers on how to resolve this error - but I can't figure out what's going wrong. Any help would be appreciated!
You should make car_id a primary key in cars.
Note: I had the same problem, and it was because the referenced field was in a different collation in the 2 different tables (they had exact same type).
Make sure all your referenced fields have the same type AND the same collation!
Check that BOTH tables have the same ENGINE. For example if you have:
CREATE Table FOO ();
and:
CREATE Table BAR () ENGINE=INNODB;
If you try to create a constraint from table BAR to table FOO, it will not work on certain MySQL versions.
Fix the issue by following:
CREATE Table FOO () ENGINE=INNODB;
Subtle, but this error got me because I forgot to declare a smallint column as unsigned to match the referenced, existing table which was "smallint unsigned." Having one unsigned and one not unsigned caused MySQL to prevent the foreign key from being created on the new table.
id smallint(3) not null
does not match, for the sake of foreign keys,
id smallint(3) unsigned not null
I got this completely worthless and uninformative error when I tried to:
ALTER TABLE `comments` ADD CONSTRAINT FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE SET NULL ON UPDATE CASCADE;
My problem was in my comments table, user_id was defined as:
`user_id` int(10) unsigned NOT NULL
So... in my case, the problem was with the conflict between NOT NULL, and ON DELETE SET NULL.
Also both the tables need to have same character set.
for e.g.
CREATE TABLE1 (
FIELD1 VARCHAR(100) NOT NULL PRIMARY KEY,
FIELD2 VARCHAR(100) NOT NULL
)ENGINE=INNODB CHARACTER SET utf8 COLLATE utf8_bin;
to
CREATE TABLE2 (
Field3 varchar(64) NOT NULL PRIMARY KEY,
Field4 varchar(64) NOT NULL,
CONSTRAINT FORIGEN KEY (Field3) REFERENCES TABLE1(FIELD1)
) ENGINE=InnoDB;
Will fail because they have different charsets. This is another subtle failure where mysql returns same error.
I use Ubuntu linux, and in my case the error was caused by incorrect statement syntax (which I found out by typing perror 150 at the terminal, which gives
MySQL error code 150: Foreign key constraint is incorrectly formed
Changing the syntax of the query from
alter table scale add constraint foreign key (year_id) references year.id;
to
alter table scale add constraint foreign key (year_id) references year(id);
fixed it.
The referenced field must be a "Key" in the referenced table, not necessarily a primary key. So the "car_id" should either be a primary key or be defined with NOT NULL and UNIQUE constraints in the "Cars" table.
And moreover, both fields must be of the same type and collation.
I also received this error (for several tables) along with constraint errors and MySQL connecting and disconnecting when attempting to import an entire database (~800 MB). My issue was the result of The MySQL server max allowed packets being too low. To resolve this (on a Mac):
Opened /private/etc/my.conf
Under # The MySQL server, changed max_allowed_packet from 1M to 4M (You may need to experiment with this value.)
Restarted MySQL
The database imported successfully after that.
Note I am running MySQL 5.5.12 for Mac OS X (x86 64 bit).
check to make the field you are referencing to is an exact match with foreign key, in my case one was unsigned and the other was signed so i just changed them to match and this worked
ALTER TABLE customer_information
ADD CONSTRAINT fk_customer_information1
FOREIGN KEY (user_id)
REFERENCES users(id)
ON DELETE CASCADE
ON UPDATE CASCADE
Solved:
Check to make sure Primary_Key and Foreign_Key are exact match with data types.
If one is signed another one unsigned, it will be failed.
Good practice is to make sure both are unsigned int.
I was using a duplicate Foreign Key Name.
Renaming the FK name solved my problem.
Clarification:
Both tables had a constraint called PK1, FK1, etc. Renaming them/making the names unique solved the problem.
The referenced column must be an index of a single column or the first column in multi column index, and the same type and the same collation.
My two tables have the different collations. It can be shown by issuing show table status like table_name and collation can be changed by issuing alter table table_name convert to character set utf8.
all, I solved a problem and wanted to share it:
I had this error <>
The issue was in that in my statement:
alter table system_registro_de_modificacion add foreign key
(usuariomodificador_id) REFERENCES Usuario(id) On delete restrict;
I had incorrectly written the CASING: it works in Windows WAMP, but in Linux MySQL it is more strict with the CASING, so writting "Usuario" instead of "usuario" (exact casing), generated the error, and was corrected simply changing the casing.