生成UPDATE语句

declare
  v_Sql         varchar2(4000);
  v_Owner_Name  varchar2(4000) default 'BASIC';/*需要导出表的用户*/
  v_Table_Name  varchar2(4000) default Upper('bsc_user_t');/*需要导出表的名称*/
  v_Where_Sql   varchar2(4000);
  i             number default 1;
  v_Column_Name varchar2(4000);
  type Cur_Alldata is ref cursor;
  l_Alldata Cur_Alldata;
  v_Row     varchar2(3999);
  v_Cbatch  number default 500;/*每格几行commit*/
begin

  v_Sql := 'select ''UPDATE ' || v_Table_Name || ' SET ';
  /*查询表的列及类型以及是否主键列*/
  for Curg in (select Tc.Column_Name
                     ,Tc.Data_Type
                     ,Decode(Pk.Column_Name, null, 'NO', 'YES') Pk_Flag
                 from All_Tab_Cols Tc
                     ,(select Ic.Column_Name
                         from All_Constraints c
                             ,All_Ind_Columns Ic
                        where 1 = 1
                          and c.Owner = Ic.Index_Owner
                          and c.Index_Name = Ic.Index_Name
                          and c.Table_Name = v_Table_Name
                          and c.Constraint_Type = 'P') Pk
                where Tc.Owner = v_Owner_Name
                  and Tc.Column_Name = Pk.Column_Name(+)
                  and Tc.Table_Name = v_Table_Name