oracle存储过程生成xml

我整理了一个方法
1.创建如下存储过程，注意将其中location =>'d:\work'之中的目录改为你本机的某个目录.

create or replace procedure getXML(newContext_qry varchar2,rowSettag varchar2,rowTag varchar2,filename varchar2) is
-- Input query string
-- Input rowsetTag , the root tag
-- Input row level tag
-- Input file name
-- Note make sure that before running this procedure, it is required that UTL_FILE_DIR must
-- be set in init.ora file In this code it has been set to d:\work.
begin
declare
qryCtx dbms_xmlgen.ctxHandle ;
result clob;
lob_length     integer;
read_amount    integer;
read_offset    integer;
buffer         varchar2(100);
loc            varchar2(100) := 'usr_dir';
f_hand         utl_file.file_type;

Begin
        -- Setting up offset and no. of chars to be read in
        -- in one go from clob datatype.
        read_offset := 1;
        read_amount := 75;

        dbms_output.put_line('opening');
        --Opening file
        f_hand := Utl_File.Fopen(location =>'d:\work',
                                 filename =>filename,
                                 open_mode =>'w',
                                 max_linesize => 32767);
        dbms_output.put_line('file open');
       
        -- Creating new context
        qryCtx := dbms_xmlgen.newContext(newContext_qry);
       
        -- Defining Rowsettag
        DBMS_XMLGEN.setRowSetTag(qryCtx,rowSettag);

        -- Defining Rowtag     
        DBMS_XMLGEN.setRowTag(qryCtx,rowTag);

        -- Generating XML and storing in an clob datatype              
        result :=DBMS_XMLGEN.getXML(qryCtx);

        dbms_output.put_line('xml generated');
       
        -- Getting the length of the data stored in Clob
        lob_length := dbms_lob.getlength(result);

        -- Reading data from clob variable and writng into file.
        while (lob_length > 0) loop
        dbms_lob.read(result,read_amount,read_offset,buffer);
        dbms_output.put_line('writing in file');
        utl_file.put(f_hand,buffer);
        dbms_output.put_line('written');
        read_offset := read_offset+read_amount;
        lob_length := lob_length-read_amount;
        if lob_length < read_amount then
           read_amount := lob_length;
        end if;
        end loop;
        utl_file.fclose(f_hand);



        EXCEPTION WHEN UTL_FILE.INVALID_PATH THEN
        RAISE_APPLICATION_ERROR(-20100,'Invalid Path');

        WHEN UTL_FILE.INVALID_MODE THEN
        RAISE_APPLICATION_ERROR(-20101,'Invalid Mode');

        WHEN UTL_FILE.INVALID_OPERATION then
        RAISE_APPLICATION_ERROR(-20102,'Invalid Operation');

        WHEN UTL_FILE.INVALID_FILEHANDLE then
        RAISE_APPLICATION_ERROR(-20103,'Invalid Filehandle');

        WHEN UTL_FILE.WRITE_ERROR then
        RAISE_APPLICATION_ERROR(-20104,'Write Error');

        WHEN UTL_FILE.READ_ERROR then
        RAISE_APPLICATION_ERROR(-20105,'Read Error');

        WHEN UTL_FILE.INTERNAL_ERROR then
        RAISE_APPLICATION_ERROR(-20106,'Internal Error');

        WHEN OTHERS THEN
        UTL_FILE.FCLOSE(f_hand);
       

end;
end;
/

2.修改init.ora参数文件中的参数utl_file_dir，将其值指定为和存储过程中location指定的目录，如D:\work，重新启动数据库。

3.登录后，执行类似如下语句
execute getXML('select * from tab','TAB','RECORD','shanfei.xml')
参数1：SQL语句
参数2：XML文件中将生成的根元素
参数3：XML文件中表格每行代表的元素
参数4：生成的xml文件名称

生成xml文件内容类似如下：
<?xml version="1.0"?>
<tab>
<record>
  <TNAME>ACCOUNTINFO</TNAME>
  <TABTYPE>VIEW</TABTYPE>
</record>
<record>
  <TNAME>ACCOUNTSTATUS</TNAME>
  <TABTYPE>VIEW</TABTYPE>
</record>