Adding NOT NULL Constraint with ALTER TABLE statement (Oracle)-CodePudding

this is my PL-SQL statement

ALTER TABLE regions MODIFY (region_name VARCHAR(40) DEFAULT 'Euro') CONSTRAINT region_nn NOT NULL;

The column 'region_name' has NULL values I want to replace with 'Euro'. I get an error with this, and I'm wondering if I have the syntax wrong or if it's impossible to place a default value when adding the NOT NULL constraint and I have to do it as two separate SQL statements

Thank you for your help'

CodePudding user response：

adding a constrain does not modify any existing data, it only modifies the definition of your table. Fix your data first, then add the constraint - or add the constraint with the defererred keyword and then fix the data. Either way, you'll manually have to update the data.