(原创)oracle目录及Long类型操作

--创建一个表

create table ascii_docs

(

id number,

document long

);

--创建一个目录

create or replace directory OUT_PATH as 'c:\temp';

--给目录授予权限

grant read, write on directory OUT_PATH to test;

create or replace function dump_doc(docid in number,filename in varchar2) return varchar2 is

data_chunk varchar2(254);

chunk_size number :=254;

chunk_size_returned number;

--set location to be the directory in which the file should go.

location varchar2(20) := 'OUT_PATH';

mycursor number;

stmt varchar2(1024);

cur_pos number :=0;

rows number;

dummy number;

file_handle utl_file.file_type;

status varchar2(50);

begin

--open the file for writing.

file_handle := utl_file.fopen(location,filename,'w');

--bind the doctoget host variable with the plsql parameter docid

--whitch is passed into the function

stmt := 'select document from ascii_docs where id = :doctoget';

mycursor := dbms_sql.open_cursor;

dbms_sql.parse(mycursor,stmt,dbms_sql.v7);

dbms_sql.bind_variable(mycursor,':doctoget',docid);

--only doing one fetch for the primary key as assuming the whole

--document is stored in one row

dbms_sql.define_column_long(mycursor,1);

dummy := dbms_sql.execute(mycursor);

rows := dbms_sql.fetch_rows(mycursor);

loop

--fetch 'chunks of the long until we have got the lot

dbms_sql.column_value_long(mycursor,1,chunk_size,cur_pos,data_chunk,chunk_size_returned);

utl_file.put(file_handle,data_chunk);

cur_pos := cur_pos + chunk_size;

exit when chunk_size_returned =0;

end loop;

dbms_sql.close_cursor(mycursor);

utl_file.fclose(file_handle);

return('success');

exception

when others then

utl_file.fclose(file_handle);

raise;

return('Fallre');

end dump_doc;