How to create a check constraint between two columns in SQL?
It might (probably does) depend on the data base you use.
Comparing to the oracle syntax (e.g. here: http://www.techonthenet.com/oracle/check.php), what you are missing might be a ',' between NULL and CONSTRAINT
The problem is that you have defined it as a column level constraint but it references other columns. You must define a constraint at the table level.
ALTER TABLE bp ADD CONSTRAINT CK_limit CHECK ( upperlimit > lowerlimit)
Here's proper the SQL query...
CREATE TABLE bp (bpid VARCHAR(5),FOREIGN KEY (bpid) REFERENCES designation(desigid), upperlimit DECIMAL(10,2) NOT NULL,lowerlimit DECIMAL(10,2) NOT NULL,increment DECIMAL(10,2) NOT NULL,CONSTRAINT llvalid CHECK (upperlimit > lowerlimit));Note the comma after NOT NULL and CONSTRAINT in the last line.