parse CSV file .. problem with managing primary key?

Question

i just created a java file to parse a csv files and saved them into an oracle database.. but i need a field ID which acts as a primary key.. and i am a bit confused abt looping..

Answer 1

I think all you need to do is utilize a sequence (as suggested by Ronnis)

as such

CREATE SEQUENCE FIELD_ID_SEQ START WITH 1 INCREMENT BY 1 NOCYCLE NOCACHE; 
/*NOTE THE SEQUENCE, WHILE INCREMENTING, IS NOT GUARANTEED TO BE 1,2,3,4...N ->expect gaps in the #*/

Now either in your java app where you are saving the data:

"INSERT INTO TABLE_OF_CSV(FIELD_ID, FIELD_COLA, FIELD_COLB) VALUES(FIELD_ID_SEQ.NEXTVAL, ?,?);"

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OR

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Now if you are using a procedure (or a procedure within a package) you can do this (note this returns the primary key back to the calling app)

create procedure insertIntoCSVTable(pCOLA IN TABLE_OF_CSV.FIELD_COLA%TYPE 
                                  , pCOLB IN TABLE_OF_CSV.FIELD_COLB%TYPE
                                  , pFIELD_ID OUT TABLE_OF_CSV.FIELD_ID%TYPE)
AS
BEGIN

    INSERT INTO TABLE_OF_CSV(FIELD_ID, FIELD_COLA, FIELD_COLB) 
    VALUES(FIELD_ID_SEQ.NEXTVAL, pCOLA, pCOLB)
    RETURNING FIELD_ID
    INTO pFIELD_ID
    ;

END insertIntoCSVTable;

no looping required assuming you are already looping in your java code (assuming a row-by-row insert)

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OR

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You may use a trigger to insert a new value into the table: create or replace

TRIGGER TABLE_OF_CSV_TRG BEFORE INSERT ON TABLE_OF_CSV 
FOR EACH ROW 
BEGIN
  <<COLUMN_SEQUENCES>>
  BEGIN
    IF :NEW.FIELD_ID IS NULL THEN
      SELECT FIELD_ID_SEQ.NEXTVAL INTO :NEW.FIELD_ID FROM DUAL;
    END IF;
  END COLUMN_SEQUENCES;
END;

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