Errors in PLSQL - - sql

Question

Morning,
I'm trying to write a script that will convert Unload tables (UNLD to HDL files) creating a flat file using PLSQL. I keep getting syntax errors trying to run it and would appreciate some help from an expert out there!
Here are the errors:
Error(53,21): PLS-00330: invalid use of type name or subtype name
Error(57,32): PLS-00222: no function with name 'UNLDTABLE' exists in this scope
Our guess is that the unldTable variable is being treated as a String, rather than a database table object (Not really expereinced in PLSQL)
CREATE OR REPLACE PROCEDURE UNLD_TO_HDL (processComponent IN VARCHAR2)
IS
fHandle UTL_FILE.FILE_TYPE;
concatData VARCHAR2(240);
concatHDLMetaTags VARCHAR2(240);
outputFileName VARCHAR2(240);
TYPE rowArrayType IS TABLE OF VARCHAR2(240);
rowArray rowArrayType;
emptyArray rowArrayType;
valExtractArray rowArrayType;
hdlFileName VARCHAR2(240);
unldTable VARCHAR2(240);
countUNLDRows Number;
dataType VARCHAR2(240);
current_table VARCHAR2(30);
value_to_char VARCHAR2(240);
BEGIN
SELECT HDL_FILE_NAME
INTO hdlFileName
FROM GNC_HDL_CREATION_PARAMS
WHERE PROCESS_COMPONENT = processComponent;
SELECT UNLD_TABLE
INTO unldTable
FROM GNC_HDL_CREATION_PARAMS
WHERE PROCESS_COMPONENT = processComponent
FETCH NEXT 1 ROWS ONLY;
SELECT LISTAGG(HDL_META_TAG,'|')
WITHIN GROUP(ORDER BY HDL_META_TAG)
INTO concatHDLMetaTags
FROM GNC_MIG_CONTROL
WHERE HDL_COMP = processComponent;
SELECT DB_FIELD
BULK COLLECT INTO valExtractArray
FROM GNC_MIG_CONTROL
WHERE HDL_COMP = processComponent
ORDER BY HDL_META_TAG;
fHandle := UTL_FILE.FOPEN('./', hdlFileName, 'W');
UTL_FILE.PUTF(fHandle, concatHDLMetaTags + '\n');
SELECT num_rows INTO countUNLDRows FROM user_tables where table_name = unldTable;
FOR row in 1..countUNLDRows LOOP
rowArray := emptyArrayType;
FOR value in 1..valExtractArray.COUNT LOOP
rowArray.extend();
SELECT data_type INTO dataType FROM all_tab_columns where table_name = unldTable AND column_name = valExtractArray(value);
IF dataType = 'VARCHAR2' THEN (SELECT valExtractArray(value) INTO value_to_char FROM current_table WHERE ROWNUM = row);
ELSIF dataType = 'DATE' THEN (SELECT TO_CHAR(valExtractArray(value),'YYYY/MM/DD') INTO value_to_char FROM current_table WHERE ROWNUM = row);
ELSIF dataType = 'NUMBER' THEN (SELECT TO_CHAR(valExtractArray(value)) INTO value_to_char FROM current_table WHERE ROWNUM = row);
ENDIF;
rowArray(value) := value_to_char;
END LOOP;
concatData := NULL;
FOR item in 1..rowArray.COUNT LOOP
IF item = rowArray.COUNT
THEN concatData := (COALESCE(concatData,'') || rowArray(item));
ELSE concatData := (COALESCE(concatData,'') || rowArray(item) || '|');
END IF;
END LOOP;
UTL_FILE.PUTF(fHandle, concatData + '/n');
END LOOP;
UTL_FILE.FCLOSE(fHandle);
END;
Thanks,
Adam

Answer 1

I believe it is just an overlook in your code. You define unldTable as a varchar, which is used correctly until you try to access it as if it were a varray on line 51
rowArray(value) := unldTable(row).valExtractArray(value);
Given that you have not defined it as a varray, unldTable(row) is making the interpreter believe that you are referring to a function.
EDIT
Now that you have moved on, you should resolve the problem of invoking SELECT statements on tables that are unknown at runtime. To do so you need to make use of Dynamic SQL; you can do it in several way, the most direct being an Execute immediate statement in your case:
mystatement := 'SELECT valExtractArray(value) INTO :value_to_char FROM ' || current_table || ' WHERE ROWNUM = ' || row;
execute immediate mystatement USING OUT value_to_char;

Answer 2

It looks like you need to generate a cursor as
select [list of columns from GNC_MIG_CONTROL.DB_FIELD]
from [table name from GNC_HDL_CREATION_PARAMS.UNLD_TABLE]
Assuming setup like this:
create table my_table (business_date date, id integer, dummy1 varchar2(1), dummy2 varchar2(20));
create table gnc_hdl_creation_params (unld_table varchar2(30), process_component varchar2(30));
create table gnc_mig_control (db_field varchar2(30), hdl_comp varchar2(30), hdl_meta_tag integer);
insert into my_table(business_date, id, dummy1, dummy2) values (date '2018-01-01', 123, 'X','Some more text');
insert into gnc_hdl_creation_params (unld_table, process_component) values ('MY_TABLE', 'XYZ');
insert into gnc_mig_control (db_field, hdl_comp, hdl_meta_tag) values ('BUSINESS_DATE', 'XYZ', '1');
insert into gnc_mig_control (db_field, hdl_comp, hdl_meta_tag) values ('ID', 'XYZ', '2');
insert into gnc_mig_control (db_field, hdl_comp, hdl_meta_tag) values ('DUMMY1', 'XYZ', '3');
insert into gnc_mig_control (db_field, hdl_comp, hdl_meta_tag) values ('DUMMY2', 'XYZ', '4');
You could build a query like this:
select unld_table, listagg(expr, q'[||'|'||]') within group (order by hdl_meta_tag) as expr_list
from ( select t.unld_table
, case tc.data_type
when 'DATE' then 'to_char('||c.db_field||',''YYYY-MM-DD'')'
else c.db_field
end as expr
, c.hdl_meta_tag
from gnc_hdl_creation_params t
join gnc_mig_control c
on c.hdl_comp = t.process_component
left join user_tab_columns tc
on tc.table_name = t.unld_table
and tc.column_name = c.db_field
where t.process_component = 'XYZ'
)
group by unld_table;
Output:
UNLD_TABLE EXPR_LIST
----------- --------------------------------------------------------------------------------
MY_TABLE to_char(BUSINESS_DATE,'YYYY-MM-DD')||'|'||ID||'|'||DUMMY1||'|'||DUMMY2
Now if you plug that logic into a PL/SQL procedure you could have something like this:
declare
processComponent constant gnc_hdl_creation_params.process_component%type := 'XYZ';
unloadSQL long;
unloadCur sys_refcursor;
text long;
begin
select 'select ' || listagg(expr, q'[||'|'||]') within group (order by hdl_meta_tag) || ' as text from ' || unld_table
into unloadSQL
from ( select t.unld_table
, case tc.data_type
when 'DATE' then 'to_char('||c.db_field||',''YYYY/MM/DD'')'
else c.db_field
end as expr
, c.hdl_meta_tag
from gnc_hdl_creation_params t
join gnc_mig_control c
on c.hdl_comp = t.process_component
left join user_tab_columns tc
on tc.table_name = t.unld_table
and tc.column_name = c.db_field
where t.process_component = processComponent
)
group by unld_table;
open unloadCur for unloadSQL;
loop
fetch unloadCur into text;
dbms_output.put_line(text);
exit when unloadCur%notfound;
end loop;
close unloadCur;
end;
Output:
2018/01/01|123|X|Some more text
2018/01/01|123|X|Some more text
Now you just have to make that into a procedure, change dbms_output to utl_file and add your meta tags etc and you're there.
I've assumed there is only one distinct unld_table per process component. If there are more you'll need a loop to work through each one.
For a slightly more generic approach, you could build a cursor-to-csv generator which could encapsulate the datatype handling, and then you'd only need to build the SQL as select [columns] from [table]. You might then write a generic cursor to file processor, where you pass in the filename and a cursor and it does the lot.
Edit: I've updated my cursor-to-csv generator to provide file output, so you just need to pass it a cursor and the file details.