Using foreign key as an enum type : ENUM « Data Type « SQL / MySQL






  1. SQL / MySQL
  2. Data Type
  3. ENUM

Using foreign key as an enum type

   
mysql>
mysql> CREATE TABLE SEXES (SEX CHAR(1) NOT NULL PRIMARY KEY)
    -> ;
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO SEXES VALUES ('M'),('F')
    -> ;
Query OK, 2 rows affected (0.00 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql>
mysql> CREATE TABLE EmployeeS_SMALL2
    ->       (EmployeeNO     INTEGER NOT NULL PRIMARY KEY,
    ->        NAME         CHAR(15) NOT NULL,
    ->        INITIALS     CHAR(3) NOT NULL,
    ->        BIRTH_DATE   DATE,
    ->        SEX          CHAR(1),
    ->        FOREIGN KEY (SEX) REFERENCES SEXES (SEX));
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql> drop table sexes;
ERROR 1217 (23000): Cannot delete or update a parent row: a foreign key constraint fails
mysql> drop table Employees_small2;
Query OK, 0 rows affected (0.00 sec)








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