Code review : why table name is invalid

Question

Greetings all,
I have written the following code to check if any column is null for all rows in a table. I'm confused as to why the column name is recognized but not the table name. If the table name is hard coded, executes.
Any and all assistance is greatly appreciated.
declare
l_null_cnt pls_integer := 0;
l_sql_stmt varchar2(100);
l_col_name user_tab_columns.column_name%type;
l_tbl_name user_tab_columns.column_name%type;
begin
for x in (
select table_name, column_name
from user_tab_columns
where nullable = 'Y'
and table_name = <TABLE_NAME>
loop
dbms_output.put_line(x.column_name||' '||x.table_name);
l_col_name := x.column_name;
l_tbl_name := x.table_name;
l_sql_stmt := 'select count(:1) from :2';
execute immediate l_sql_stmt into l_null_cnt using l_col_name, l_tbl_name;
case when ( l_null_cnt = 0 ) then
dbms_output.put_line(x.column_name||' column is NULL in table '||x.table_name);
else
dbms_output.put_line('Column not null');
end case;
end loop;
end;

Answer 1

Try some thing like this,
Not tested.
DECLARE
   l_sql_stmt   VARCHAR2 (100);
   l_cnt        NUMBER;
BEGIN
   FOR x IN (SELECT table_name, column_name
               FROM user_tab_columns
              WHERE nullable = 'Y' and table_name = 'UDFACTPROVIDERS'
   LOOP
      l_sql_stmt :=
            'select count(1) from '
         || x.table_name
         || ' where '
         || x.column_name
         || ' is not null and rownum=1';
      EXECUTE IMMEDIATE l_sql_stmt INTO l_cnt;
      DBMS_OUTPUT.PUT_LINE (
            x.column_name
         || ' column is '
         || case when l_cnt> 0 then 'NOT' END
         || ' NULL in table '
         || x.table_name
   END LOOP;
END;G.