Tuple Relational Calculus:

This is a ‘non-procedural query language’, whereas ‘Relational Algebra’ is a ‘procedural query language’.

The TRC describes the desired information without giving a specific procedure for obtaining the result.

The query expression in this language is :

                                   { t / P(t) }

Consider the following relation:

R1 :  FACULTY-1

Example-1 :  Find the Faculty No, Faculty name, DNo, Qual and salaries of all the faculty, who are drawing more than 30000.

                  { t / t ϵ  Faculty-1  ˄  t[Salary] > 30000 }

Output :

Example-2 :  Find the Faculty No and Faculty name of all the faculty, who are drawing more than 40000.

                  { t / Ǝ s ϵ  Faculty-1  ( t[FNo] = s[FNo] ˄  

t[ FName] = s{FName]  ˄  s[Salary] > 40000 }

Output :

Example-3 :  Find the names of students who are studying in departments.

                   { t / Ǝ s ϵ  STUD  ( t[SName] = s[SName] ˄  

Ǝ u ϵ  DEPT ( s[DNo] = u[DNo]  ˄  u[DName] = ‘IT’ ) ) }

Consider the following relations :

Output :                                     SName

                                       Zayn

                                           Harry

 Example-4 :  Find the name of the department where ‘pqr’ is studying.

                   { t / Ǝ s ϵ DEPT  ( t[DName] = s[DName] ˄  

Ǝ u ϵ  STUD ( s[DNo] = u[DNo]  ˄  u[SName] = ‘pqr’ ) ) }

Output :                                     DName

                                                CSE

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Tuple Relational Calculus: