|
MariaDB [mydb]> create table emp( name varchar(11), id int(11));
MariaDB [mydb]> ALTER TABLE emp
-> ADD CONSTRAINT websites_unique UNIQUE (id,name);
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
MariaDB [mydb]> desc emp;
------
| Field |
Type |
Null |
Key |
Default |
Extra |
------
| name |
varchar(11) |
YES |
|
NULL |
|
| id |
int(11) |
YES |
MUL |
NULL |
|
------
2 rows in set (0.00 sec)
MariaDB [mydb]> alter table emp drop column id;
*ERROR 1072 (42000): Key column 'id' doesn't exist in table
*MariaDB [mydb]>
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