Table not found at cursor%NOTFOUND Oracle - oracle

Question

I was asked to migrate this code from Sql server
It's used to count all rows with a cursor in a database and we need it to work both on sql server and oracle. The sql server part is working fine, but the oracle part i can't figure out.
DECLARE #tablename VARCHAR(500)
DECLARE #rowname VARCHAR(500)
DECLARE #sql AS NVARCHAR(1000)
IF OBJECT_ID('tempdb..#Temp1') IS NOT NULL
DROP TABLE #Temp1
CREATE TABLE #Temp1
(
tablename varchar(max) ,
rowCounter NUMERIC(38) ,
idColumn varchar(max),
SumIdCol NUMERIC(38)
);
DECLARE db_cursor CURSOR FOR
SELECT s.name + '.' + o.name as name, c.COLUMN_NAME
FROM sys.all_objects o
join sys.schemas s on o.schema_id=s.schema_id
join INFORMATION_SCHEMA.COLUMNS c on o.name=c.TABLE_NAME
WHERE type = 'U' and s.name not like 'sys' and c.ORDINAL_POSITION=1 and c.DATA_TYPE='int'
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO #tablename,#rowname
WHILE ##FETCH_STATUS = 0
BEGIN
SET #sql =
'
insert into #Temp1 values('+
''''+#tablename+''','+
'(SELECT count(1) FROM '+#tablename+' ),'+
''''+#rowname+''''+','+
'(SELECT SUM(['+#rowname+']) FROM '+#tablename+' )'+
')'
EXEC sp_executesql #sql
FETCH NEXT FROM db_cursor INTO #tablename,#rowname
END
CLOSE db_cursor
DEALLOCATE db_cursor
select * from #Temp1
IF OBJECT_ID('tempdb..#Temp1') IS NOT NULL
DROP TABLE #Temp1
Into oracle. I decided to take on PL/SQL and wrote this:
DECLARE
v_tablename varchar2(400);
v_rowname varchar2(400);
cursor db_cursor is
select ALL_OBJECTS.OWNER || '.' || USER_TABLES.TABLE_NAME AS Tablename, USER_TAB_COLS.COLUMN_NAME AS columnName
from USER_TABLES
inner join user_tab_cols ON USER_TAB_COLS.TABLE_NAME=USER_TABLES.TABLE_NAME
inner join ALL_OBJECTS ON user_tab_cols.TABLE_NAME=ALL_OBJECTS.OBJECT_NAME
WHERE ALL_OBJECTS.OBJECT_TYPE = 'TABLE' AND USER_TAB_COLS.COLUMN_ID = 1;
begin
open db_cursor;
loop
fetch db_cursor into v_tablename,v_rowname;
EXIT WHEN db_cursor%NOTFOUND;
execute immediate 'INSERT INTO Temp1(tablename,rowCounter,idColumn,SumIdCol)
SELECT ''' || v_tablename || ''' ,COUNT(*), ''' || v_rowname ||''',SUM(''' || v_rowname ||''') FROM ' || v_tablename;
end loop;
CLOSE db_cursor;
END;
The issue i have is that i get Invalid table or view at line 42 (This line is EXIT WHEN db_cursor%NOTFOUND;)
I know this solution isn't the best but any help would be appreciated. Thanks

Answer 1

I'm not quite sure what are the last two columns in the temp1 table supposed to contain; the first column (why?) and some "sum" value, but - which one?
Anyway: in Oracle, you might start with this code (that compiles and does something; could/should be improved, perhaps):
Target table:
SQL> create table temp1
2 (tablename varchar2(70),
3 rowcounter number,
4 idcolumn varchar2(30),
5 sumidcol number
6 );
Table created.
Anonymous PL/SQL block; note that you need just all_tables and all_tab_columns as they contain all info you need. If you use all_objects, you have to filter tables only (so, why use it at all?).
As all_ views contain all tables/columns you have access to, I filtered only tables owned by user SCOTT because - if I left them all, I'd get various owners (such as SYS and SYSTEM - do you need them too?) and 850 tables.
SQL> select count(distinct owner) cnt_owner, count(*) cnt_tables
2 from all_tables;
CNT_OWNER CNT_TABLES
---------- ----------
19 850
SQL>
Maybe you'd actually want to use user_ views instead.
This code lists all tables, the first column and number of rows in each table:
SQL> declare
2 l_cnt number;
3 begin
4 for cur_r in (select a.owner,
5 a.table_name,
6 c.column_name
7 from all_tables a join all_tab_columns c on c.owner = a.owner
8 and c.table_name = a.table_name
9 where c.column_id = 1
10 and a.owner in ('SCOTT')
11 )
12 loop
13 execute immediate 'select count(*) from ' || cur_r.owner ||'.'||
14 '"' || cur_r.table_name ||'"' into l_cnt;
15
16 insert into temp1 (tablename, rowcounter, idcolumn, sumidcol)
17 values (cur_r.owner ||'.'||cur_r.table_name, l_cnt, cur_r.column_name, null);
18 end loop;
19 end;
20 /
PL/SQL procedure successfully completed.
Result is then:
SQL> select * from temp1 where rownum <= 10;
TABLENAME ROWCOUNTER IDCOLUMN SUMIDCOL
----------------------------------- ---------- --------------- ----------
SCOTT.ACTIVE_YEAR 1 YEAR
SCOTT.BONUS 0 ENAME
SCOTT.COPY_DEPARTMENTS 1 DEPARTMENT_ID
SCOTT.DAT 0 DA
SCOTT.DEPARTMENTS 1 DEPARTMENT_ID
SCOTT.DEPT 4 DEPTNO
SCOTT.DEPT_BACKUP 4 DEPTNO
SCOTT.EMP 14 EMPNO
SCOTT.EMPLOYEE 4 EMP_ID
SCOTT.EMPLOYEES 9 EMPLOYEE_ID
10 rows selected.
SQL>

Answer 2

You are getting the Table not found exception because you have lower-case table names and you are using unquoted identifiers, which Oracle will implicitly convert to upper-case and then because they are upper- and not lower-case they are not found.
You need to use quoted identifiers so that Oracle respects the case-sensitivity in the table names. You can also use an implicit cursor and can pass the values using bind variables (where possible) rather than using string concatenation:
BEGIN
FOR rw IN (SELECT t.owner,
t.table_name,
c.column_name
FROM all_tables t
INNER JOIN all_tab_cols c
ON (t.owner = c.owner AND t.table_name = c.table_name)
WHERE t.owner = USER
AND c.column_id = 1)
LOOP
EXECUTE IMMEDIATE 'INSERT INTO Temp1(tablename,rowCounter,idColumn)
SELECT :1, COUNT(*), :2 FROM "' || rw.owner || '"."' || rw.table_name || '"'
USING rw.table_name, rw.column_name;
END LOOP;
END;
/
fiddle