Pass a table name and time stamp variable to a PL/SQL - oracle

Question

I am writing a below PL/SQL code in SQL developer to delete data from a table with a timestamp column in the where condition. How can I modify this code to pass the table name and the timestamp value to values that I want based on what table and time records I want to delete the data from and create a stored procedure that can be reused.
DBMS_OUTPUT.ENABLE;
DECLARE
counter INTEGER := 0;
stop INTEGER;
BEGIN
dbms_output.put_line('START');
LOOP
counter := counter + 1;
DELETE my_schema.test
WHERE t = '10-JUN-20 04.33.46.000000000 AM'
AND ROWNUM <= 100000;
SELECT COUNT(*)
INTO stop
FROM my_schema.test
WHERE t = '10-JUN-20 04.33.46.000000000 AM';
EXIT WHEN stop <= 0;
COMMIT;
END LOOP;
dbms_output.put_line('Counter: ' || counter);
dbms_output.put_line('Left: ' || stop);
COMMIT;
END;

Answer 1

Adapting your anonymous to a stored procedure will, as indicated, require converting it to dynamic SQL. Always more difficult. And subject to SQL injection. For this you should validate string replacement parameters. I have a couple other changes:
Pass the desired as a timestamp, not a string, this allows/forces the
calling routine to determine the format and necessary conversion, if
any.
Added a parameter for column name as well. This frees naming columns
from the requirement of the procedure.
There is no need to count remaining items. Your loop processes until
that value reaches 0, but this can be determined by the number of
rows deleted on the last pass. Delete sets sql%rowcount to the number
of rows deleted. When the pass deletes 0 rows the process is
complete.
Removed the results display and the commit from the procedure, again
offloading this to the caller.
create or replace
procedure delete_values_by_timestamp
( p_table_name in varchar2
, p_column_name in varchar2
, p_timestamp in timestamp
, p_result_msg out varchar2
)
IS
table_name_parameter_invalid exception;
pragma exception_init(table_name_parameter_invalid, -44002);
column_name_parameter_invalid exception;
pragma exception_init(column_name_parameter_invalid, -44003);
k_nl constant varchar2(1) := chr(10);
k_max_delete_per_interation constant integer := 100000;
k_base_delete varchar2(256) :=
'delete from <table_name>' ||
' where <column_name> <= :1' ||
' and rownum <= :2';
v_delete_sql varchar2 (256) ;
v_rows_deleted integer := 0;
begin
v_delete_sql := replace(replace(k_base_delete,'<table_name>', dbms_assert.sql_object_name(p_table_name))
,'<column_name>',dbms_assert.simple_sql_name(p_column_name));
dbms_output.put_line('Running SQL:' || k_nl || v_delete_sql);
loop
execute immediate v_delete_sql using p_timestamp, k_max_delete_per_interation;
exit when sql%rowcount = 0;
v_rows_deleted :=v_rows_deleted + sql%rowcount;
end loop;
if v_rows_deleted = 0
then
p_result_msg := 'No Data Found';
else
p_result_msg := 'Number of Rows Deleted ' || to_char(v_rows_deleted);
end if;
exception
when table_name_parameter_invalid then
raise_application_error(-20199,'Invalid Table Name (' || p_table_name || ') specified.');
when column_name_parameter_invalid then
raise_application_error(-20198,'Invalid Column Name (' || p_column_name || ') specified.');
end delete_values_by_timestamp;
See example: In the example I reduce the number of rows deleted on each iteration from 100000 to 20. An additionally enhancement would be to pass the number of rows for each iteration as a parameter.

Answer 2

I couldn't test it but you could create a function whcih takes the table name and the timestamp as parameter.
As long you want to delete every record with the given timestamp you don't need to loop for each record.
This function should be just an example.
FUNCTION delete_values_by_timestamp (p_table_name IN VARCHAR2 DEFAULT NULL,
p_timestamp IN VARCHAR2 DEFAULT NULL)
RETURN VARCHAR2
IS
v_count NUMBER := 0;
v_query VARCHAR2 (500) := '';
BEGIN
IF p_table_name IS NOT NULL
THEN
IF p_timestamp IS NOT NULL
THEN
v_query := 'SELECT COUNT(*)
FROM my_schema.' || p_table_name | '
WHERE t = TO_DATE(''' || p_timestamp ||''', ''DD.MM.YYYY HH24:MI:SS.SSSS'')';
EXECUTE IMMEDIATE v_query INTO v_count;
IF v_count > 0
THEN
v_query := 'DELETE FROM my_schema.' || p_table_name || '
WHERE t = TO_DATE(''' || p_timestamp ||''', ''DD.MM.YYYY HH24:MI:SS.SSSS'')';
EXECUTE IMMEDIATE v_query;
ELSE
RETURN 'NO RECORDS FOUND!';
END IF;
ELSE
RETURN 'TIMESTAMP EMPTY!';
END IF;
ELSE
RETURN 'TABLE NAME EMPTY!';
END IF;
END;