当我在mysql中有外键时如何插入列

Question

Hello guys I have some problems I have been trying to inser data to a column which have a foreign key in MSQL But I can't make it work. I would appreciate if somebody help me with this.

 Category
(
 idCategory int(20) auto_increment not null,
 NameCategory varchar(40) not null,
 PRIMARY KEY (idCategory)
);

SubCategory
( 
 idSubCategory int(10)not null primary key auto_increment ,
 NameSub varchar(40) not null,
 FK_Category int not null 
);

ALTER TABLE SubCategory auto_increment=1;

ALTER TABLE SubCategory
ADD FOREIGN KEY (PK_Category)
REFERENCES Category (idCategory);

I have tried this 3 ways but nothing works

INSERT INTO Subcategory (NameSub)
VALUES ( 'Nisan');

INSERT INTO Subcategory (idSubCategory, NameSub,PK_Category)
VALUES (01, 'Nisan', 01);

INSERT INTO subcategory (NameSub, PK_Category) VALUES
    ( 'Nisan' SELECT idCategory from Category WHERE idCategory = 1 );

Answer 1

For some reason your Foreign key constrains script didn't work for me so I did it another an alternate way.
I worked out why afterwards, you reference you have ADD FOREIGN KEY (PK_Category) rather than (FK_Category)

CREATE TABLE Category
(
 idCategory int(20) auto_increment not null,
 NameCategory varchar(40) not null,
 PRIMARY KEY (idCategory)
);

CREATE TABLE SubCategory
( 
 idSubCategory int(10)not null primary key auto_increment ,
 NameSub varchar(40) not null,
 FK_Category int not null,
 INDEX IDX_Category(FK_Category),
 FOREIGN KEY (FK_Category) 
        REFERENCES Category(idCategory)
        ON DELETE CASCADE  
);


ALTER TABLE SubCategory auto_increment=1;

And here are the inserts

INSERT INTO Category (NameCategory)
VALUES ('Car');

INSERT INTO Subcategory (NameSub,FK_Category)
VALUES ('Nisan', 01);

As you didn't specify the contents of the table of Category I've created one.

Note: The issue you may be having is that your parent table is empty, and then it would error.

SQL Fiddle