/SQL/How to make multiple keys as primary in bdms

How to make multiple keys as primary in bdms

CREATE TABLE `Donor`(
  `did` int(50) NOT NULL,
  `oid` int(50) NOT NULL,
  `dname` varchar(50) NOT NULL,
  `dblood` varchar(50) NOT NULL,
  PRIMARY KEY (`did`, `oid`)
);

Similar codes

0 vote125 views1 answer
Postgresql delete type
SQL
0 vote132 views1 answer
Search db for table name
SQL
0 vote121 views1 answer
Create table employees oracle
SQL
0 vote133 views2 answers
Msg 8164, Level 16, State 1, Procedure getSalaryMonth, Line 31 [Batch Start Line 13] An INSERT EXEC statement cannot be nested.
SQL
0 vote130 views1 answer
Why mysql is used?
SQL
3 votes130 views1 answer
Oracle list privileges
SQL
0 vote166 views1 answer
Mysql relationships between tables
SQL
2 votes88 views1 answer
Sql group by different columns
SQL
6 votes140 views1 answer
Oracle rank
SQL
0 vote131 views1 answer
6)selects only the DISTINCT values from the "side" column in the "Reserves" table
SQL