Assuming that your current primary key constraint is called pk_history, you can replace the following lines:
ALTER TABLE history ADD PRIMARY KEY (id)
ALTER TABLE history
DROP CONSTRAINT userId
DROP CONSTRAINT name
with these:
ALTER TABLE history DROP CONSTRAINT pk_history
ALTER TABLE history ADD CONSTRAINT pk_history PRIMARY KEY (id)
If you don’t know what the name of the PK is, you can find it with the following query:
SELECT *
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE TABLE_NAME = 'history'