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解析 CSV 文件..管理主键有问题吗？

发布于 2024-10-17 10:03:09 字数 80 浏览 2 评论 0原文

我刚刚创建了一个java文件来解析csv文件并将它们保存到oracle数据库中..但我需要一个充当主键的字段ID..而且我对abt循环有点困惑..

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蝶舞 2024-10-24 10:03:09

我认为您需要做的就是利用一个序列（如 Ronnis 所建议的）

，

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 #*/

现在在您保存数据的 java 应用程序中：

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

或者

现在，如果您正在使用一个过程（或包中的过程），您可以执行此操作（注意这会将主键返回到调用应用程序）

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;

假设您已经在 Java 代码中循环（假设逐行插入），则不需要循环，

或者

您可以使用触发器将新值插入到桌子：
创建或替换

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;

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, ?,?);"

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)

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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