ORA-00001:违反唯一约束(System.Browsers_PK)

Question

String Qry = INSERT INTO browsers (browsers.browser,browsers.engine,browsers.platform,browsers.version,browsers.grade) VALUES ('Alans browser','Gecko','every','1.0','U') RETURNING id INTO :ID

OracleConnection conn = new OracleConnection(...);
OracleCommand cmd = null;
...
cmd = new OracleCommand(Qry, conn);
OracleParameter prm = new OracleParameter();
prm = new OracleParameter(":ID", OracleDbType.Int32, ParameterDirection.ReturnValue);
cmd.Parameters.Add(prm);
cmd.ExecuteNonQuery(); //this line throws error
query.setNewRecordID(cmd.Parameters[":ID"].Value.ToString());
...

创建序列“system”。“browsers_seq”MINVALUE 1 MAXVALUE

触发器：

create or replace trigger BROWSERS_TRG  
before insert on "SYSTEM"."BROWSERS" 
for each row 
begin  
   if inserting then 
      if :NEW."ID" is null then 
         select BROWSERS_SEQ.nextval into :NEW."ID" from dual; 
      end if; 
   end if; 
end;




Answer 1

我认为你的序列有问题（我不能按原样编译）。我把它去掉了，它起作用了。

我在我的SCOTT（示例）模式中创建了一个类似的场景，如下所示：

 SCOTT@dev> CREATE TABLE "SCOTT"."EMP2"
  2    (
  3      "EMPNO"    NUMBER(4,0),
  4      "ENAME"    VARCHAR2(10 BYTE),
  5      "JOB"      VARCHAR2(9 BYTE),
  6      "MGR"      NUMBER(4,0),
  7      "HIREDATE" DATE,
  8      "SAL"      NUMBER(7,2),
  9      "COMM"     NUMBER(7,2),
 10      "DEPTNO"   NUMBER(2,0)
 11    )
 12    TABLESPACE "SYSTEM" ;

Table created.

SCOTT@dev> CREATE UNIQUE INDEX "SCOTT"."EMP2_EMPNO" ON "SCOTT"."EMP2"
  2    (
  3      "EMPNO"
  4    )
  5    TABLESPACE "SYSTEM" ;

Index created.

SCOTT@dev> set define off;
SCOTT@dev> ALTER TABLE "SCOTT"."EMP2" ADD PRIMARY KEY ("EMPNO");

Table altered.

SCOTT@dev>  CREATE SEQUENCE EMP2_SEQ MINVALUE 1 MAXVALUE 9999999999999999999999999999 INCREMENT BY 1 START WITH 21 CACHE 20 NOORDER NOCYCLE  ;

Sequence created.

SCOTT@dev> CREATE OR REPLACE TRIGGER EMP2_TRG before
  2    INSERT ON SCOTT.EMP2 FOR EACH row BEGIN IF inserting THEN IF :NEW.EMPNO IS NULL THEN
  3    SELECT EMP2_SEQ.NEXTVAL INTO :NEW.EMPNO FROM dual;
  4  END IF;
  5  END IF;
  6  END;
  7  /

Trigger created.

SCOTT@dev> commit;

Commit complete.

SCOTT@dev> INSERT INTO EMP2
  2  (ENAME)
  3  VALUES
  4  ('FRED')
  5  /

1 row created.

SCOTT@dev> commit;

Commit complete.

因此，顺序似乎是罪魁祸首。