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Resolved Understand RecId

  1. Roger
    Roger
  2. as Valentina DB Server
  3. Tuesday, August 04 2020, 04:43 PM
  4.  Subscribe via email
Hello

When I have an existing db with 2 tables person - phones. In relation 1:n (a phone can have only 1 user in this example). In this db the conection is with primary keys, comun. So far so good.

Now, if I try with Valentina and the idea from Recid and Link. How can I do this? Write the primary key to the RecId I think is not the concept.... But how know the Valkentina db what are the phones from a person? I have not found in the helps.

Reghards Roger
  1. DB_Valentina
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Sergey Pashkov
Sergey Pashkov Accepted Answer
Hello Roger,

ObjectPtr LINK is alternative to Primary Key+Foreign Key scheme.
I attached a link to article which describes ObjectPtr.

Here's an example database:


CREATE TABLE "Person"(

	"FirstName" VARCHAR ( 2044 ) );



CREATE TABLE "Phone"(

	"Number" VARCHAR ( 2044 ),

	"Person_ptr" OBJECTPTR CONSTRAINT "lnk_Person_Phone"

					REFERENCES "Person"

					ON DELETE RESTRICT INDEXED );



INSERT INTO "Person" ("FirstName") VALUES ('Robert'); 

INSERT INTO "Person" ("FirstName") VALUES ('Brian'); 

INSERT INTO "Person" ("FirstName") VALUES ('John'); 

INSERT INTO "Person" ("FirstName") VALUES ('Peter'); 



INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('1111', 1); 

INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('2222', 3); 

INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('3333', 1); 

INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('4444', 2); 

INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('5555', NULL); 

INSERT INTO "Phone" ("Number", "Person_ptr") VALUES ('6666', NULL);


A few examples of JOIN queries on this link:


-- Ordinary JOIN

SELECT * FROM Person JOIN Phone ON Person.RecID = Phone.Person_ptr;



-- JOIN ON link

SELECT * FROM Person JOIN Phone ON lnk_Person_Phone;



-- There is only one link, so no need to specify it

SELECT * FROM Person JOIN Phone;



-- Operator -> on ObjectPtr field Person_ptr allows writing queries even without JOIN

SELECT Person_ptr->FirstName, Number FROM Phone;
References
  1. http://valentina-db.com/docs/dokuwiki/v10/doku.php?id=valentina:vcomponents:vkernel:vlink:objectptr
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  1. more than a month ago
  2. as Valentina DB Server
  3. # 1
Roger
Roger Accepted Answer
Many thanks Sergey, now its clear.

have a nice day
Roger
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  1. more than a month ago
  2. as Valentina DB Server
  3. # 2
Ruslan Zasukhin
Ruslan Zasukhin Accepted Answer
Hi Roger,

In the WIKI exists section Articles

Also good section is "Valentina Links"
References
  1. https://www.valentina-db.com/docs/dokuwiki/v10/doku.php?id=valentina:articles:articles
  2. http://valentina-db.com/dokuwiki/doku.php?id=valentina:vcomponents:vkernel:vlink:vlink
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  1. more than a month ago
  2. as Valentina DB Server
  3. # 3
Roger
Roger Accepted Answer
Thanks Ruslan, with link and pointer it works fine. About binary links I have read but not tried.

LINK RECORD (1) OF Person TO RECORD (3) OF Phone;

Is (1) and (3) the RecID from a Record and a sql command LINK make the connection (defined bevore as b9nsy link)?
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  1. more than a month ago
  2. as Valentina DB Server
  3. # 4
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