Postgresql constraint

Question

I cannot seem to get this right, I am trying to modify a field to be a foreign key, with cascading delete... what am i doing wrong?

ALTER TABLE my_table 
ADD CON         


        

Answer 1

This works to me, I add the column to the table and then add the constraint with references to the other table:

-- add column to table 
ALTER TABLE schema.table ADD COLUMN my_column type;  

-- add constraint to column 
ALTER TABLE schema.table ADD CONSTRAINT fk_name FOREIGN KEY (column)
REFERENCES schema.table (column) MATCH SIMPLE 
ON UPDATE NO ACTION ON DELETE NO ACTION;