Question

我有这个PL / SQL代码：

qrs := 'CURSOR cur IS SELECT * FROM ' || table|| 
         ' WHERE ' || direction || '=0 AND rownum <= 2000 FOR UPDATE';
v_ctx := DBMS_XMLQuery.newContext(qrs);
DBMS_XMLQuery.GetXML(v_ctx);
DBMS_XMLQuery.closeContext(v_ctx);

，在我获得XML之后，我想更新选定的行：

EXECUTE IMMEDIATE 'UPDATE ' || table || 
        ' SET ' || direction || ' = 4 WHERE CURRENT OF ' || cur;

有人可以帮帮我吗？

Answer 1

我没有玩过这个XML的东西，但是

EXECUTE IMMEDIATE 'UPDATE ' || table || 
        ' SET ' || direction || ' = 4 WHERE CURRENT OF ' || cur;

cur是游标的标识符，而不是局部变量的内容，因此更有可能使用

EXECUTE IMMEDIATE 'UPDATE ' || table || 
        ' SET ' || direction || ' = 4 WHERE CURRENT OF cur';

这假设保留了cur的上下文，我怀疑它不会。首先，'CURRENT'表示一行，但您选择的是最多2000行。我认为您需要选择（最多）2000行的标识符并单独更新。

对情况的更广泛描述可能有所帮助

Answer 2

使用suggests代替的11g R2 DBMS_XMLGEN的文档。

create table so2in (id number, proc number, desc_ varchar2(20));

insert into so2in values(100, 0, 'desc of 100');
insert into so2in values(101, 0, 'desc of 101');
insert into so2in values(102, 0, 'desc of 102');
insert into so2in values(103, 0, 'desc of 103');
insert into so2in values(104, 0, 'desc of 104');

create table so2out(r1 clob, r2 xmltype);

declare
  qryctx dbms_xmlgen.ctxhandle;
  cur sys_refcursor;
  r1 clob;
  r2 xmltype;
begin
  open cur for
    select id, desc_ from so2in where proc = 0 and rownum <= 2 for update;

  qryctx := dbms_xmlgen.newcontext(cur);
  dbms_xmlgen.setrowtag(qryctx, 'Description');
  dbms_xmlgen.setrowsettag(qryctx, 'Descriptions');

  r1 := dbms_xmlgen.getxml(qryctx);

  update so2in set proc = 1 where proc = 0 and rownum <= 2;

  dbms_xmlgen.restartquery(qryctx);

  r2 := dbms_xmlgen.getxmltype(qryCtx);

  update so2in set proc = 1 where proc = 0 and rownum <= 2;

  insert into so2out values(r1, r2);

  dbms_xmlgen.closecontext(qryctx);

  commit;
end;
/

DBMS_XMLQuery和SELECT FOR UPDATE

2 个答案: