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Re: adding SQL QUERIES to PROLOG!
Posted:
Aug 9, 2012 6:42 PM
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On Aug 8, 7:17 pm, Graham Cooper <grahamcoop...@gmail.com> wrote:
> *LOGIC, A.I. groups added since this is
>
> COMPUTER *PROGRAMMING-LOGIC* LANGUAGE DESIGN.*
>
> **
>
> 2 rules can be added to *PRO-LOG* to have nested queries like SQL!
>
> FIELD NAMES can be assigned to PREDICATE ARGUMENTS
>
> so PROLOG is compatible with standard SQL STATEMENTS.
>
> SQL:
> SELECT PERSON FROM T-CLIENTS
> WHERE "surname = smith".
>
> Prolog doesn't recorgnize the term 'surname' even if the predicate
> PERSON is defined, so SQL has a STRUCTURED WHERE statement whereas
> Prolog refers to fields via ARGUMENT position.
>
> ***microPROLOG***
>
> [bigger 2 1].
> [bigger 3 2].
> [bigger 10 5].
> [bigger tom sally].
>
> ***PROLOG***
>
> bigger(2, 1).
> bigger(3, 2).
> bigger(10, 5).
> bigger(tom, sally).
>
> ?- bigger(X,Y).
>
> X=2, Y=1
> X=3, Y=2
> X=10, Y=5
> X=tom, Y=sally
>
> ****
>
> This complicated FORMAT of output
> - the binding results of UNIFY(query, db-facts)
>
> is probably the reason PROLOG was ditched in favour of SQL.
>
> (Structured Query Language).
>
> **************************************
> ENHNANCED PROLOG GRAMMAR
> **************************************
>
> LINE ! -> NEWTABLE TABLEDEF !
> LINE ! -> NEWQUERY QUERYDEF !
>
> TABLEDEF --> [term FIELDTAIL]
> FIELDTAIL --> FIELD FIELD ... FIELD
>
> QUERYDEF --> TABLEDEF IS TABLEDEF IF TAIL
>
> ***ORIGINAL microPROLOG GRAMMAR***
>
> LINE . --> FACT .
> LINE . --> RULE .
> ?- LINE . --> ?- QUERY .
>
> RULE --> FACT IF TAIL
> QUERY --> TAIL
>
> FACT --> term
> FACT --> VAR
> FACT --> [term TAIL]
>
> TAIL --> FACT FACT ... FACT
>
> ********************************
> END ENHANCED GRAMMAR
> ********************************
>
> ****ENHANCED PROLOG****
>
> NEWTABLE [bigger BIG SMALL] !
>
> [bigger X Y] ?
>
> [bigger]
> ==============
> BIG SMALL
> --------------
> 2 1
> 3 2
> 10 5
> tom sally
>
> NEWQUERY [smaller SMALL BIG] IS [bigger BIG SMALL] !
>
> [smaller SMALL BIG] ?
>
> [smaller]
> ==============
> SMALL BIG
> --------------
> 1 2
> 2 3
> 5 10
> sally tom
>
> This is not using the RULE (filter) so it's just an equivalent table
> with different field orders.
>
> QUERYDEF --> TABLEDEF IS TABLEDEF IF TAIL
>
> where TAIL could restrict results or even JOIN two previous tables and
> nested queries.
>
> G. Cooper (BInfTech)
> --http://www.microprolog.com/LowMoon-Sun-12Stars.jpg
A constructive suggestion:
Join the discussion groups at www.mersenneforum.org
You may find a more favorable reception there.
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