Listing 3. Using Referential Integrity Checks
CREATE TABLE People (''
person_id SERIAL NOT NULL,
name VARCHAR(40) NOT NULL CHECK (name <> ''),
address1 VARCHAR(30) NULL CHECK (address1 <> ''),
address2 VARCHAR(30) NULL CHECK (address2 <> ''),
email VARCHAR(50) NOT NULL CHECK (email ~ '@'),
city VARCHAR(30) NULL CHECK (city <> ''),
state VARCHAR(2) NULL CHECK (state <> ''),
zip VARCHAR(10) NULL CHECK (zip <> ''),
PRIMARY KEY(person_id),
UNIQUE(name)
);
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