[求助]oracle执行存储过程的问题!

/*存储过程*/
create or replace procedure WLselect(earID in varchar2,dtid in varchar2,barcode in varchar2) is
strSelect varchar2(1000);
begin
strSelect:='create global temporary table yzTemp(yzEarID VARCHAR2(20),yzCustomerName varchar2(100),yzOutDate varchar2(10));'
||'insert into yzTemp'
||'select yzouttransfer.earid,customerName,yzouttransfer.outdate'
||'from yzouttransfer,customerinfo,tzintransfer'
||'where yzouttransfer.earid=tzintransfer.earid and tzintransfer.lycustomercode=customerinfo.customercode;'

||'select * from yzTemp;'
||'drop table yzTemp;';
execute immediate strSelect;

end WLselect;

/*执行存储过程语句*/

begin
wlselect('','','');
end;

会出现错误:"字符串无效!";