Translating Weak Entity Sets

• Weak entity set and identifying relationship set are translated into a single table.

  • When the owner entity is deleted, all owned weak entities must also be deleted.

CREATE TABLE Dep_Policy (

pname CHAR(20),

age INTEGER,

cost REAL,

ssn CHAR(11) NOT NULL,

PRIMARY KEY (pname, ssn),

FOREIGN KEY (ssn) REFERENCES Employees,

ON DELETE CASCADE)

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