DBMS_XMLQuery和SELECT FOR UPDATE

Question

我有這個PL / SQL代碼：

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);

，在我獲得XML后，我想更新選定的行：

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

請問有人幫幫我嗎？

Answer 1

我沒有玩過這種XML的東西

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

cur是游標的標識符，而不是局部變量的內容，因此更有可能使用它

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

這假設cur的上下文被保留，我懷疑它不會。 首先，'CURRENT'表示一行，但您選擇的是最多2000行。我認為您需要選擇（最多）2000行的標識符並單獨更新。

更廣泛的情況描述可能會有所幫助

Answer 2

11g R2的文檔建議使用DBMS_XMLGEN 。

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;
/