Tuple Relational Calculus

Antosh Dyade November 10, 2022

  • The tuple relational algebra is a nonprocedural query language. It describes the desired information without giving a specific procedure or obtaining that information.​
  • A query in the tuple relational calculus is expressed as ​
    • { t | P(t) }​
    • That is, it is the set of all tuples t such that predicate P is true for t.​
    • In tuple relational calculus ​
    • t[A] - denotes the value of tuple on attribute A.​
    • t ε  r –denotes tuple t in relation r. ​

Examples based on the following table




Example 1: Find all tuples from the depositor relation
Answer: { t | t ϵ depositor }​

Example 2: Find the loan_no, branch_name and amount for loans of over 100000.
Answer: { t | t ϵ loan ᴧ [amount] > 100000 }​




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