Error in UPSERT SQL Query in Procedure

Hi,

I am using UPSERT SQL QUery to update records in table using below query. This query is dynamic. I am populating table name and column names in to v_table_names and v_col_select.

v_string := 'UPSERT '||v_table_name||'(DATE_SK,' ||:v_col_select||', DATA_TYPE)';

v_strng := ' SELECT '''||:v_transaction_date||''','|| :v_col_select ||', DATA_TYPE,' || :ip_param ||'  FROM '||:ip_table;

v_string := v_string || v_strng;

When I call procedure i get following error.

syntax error exception: sql syntax error: incorrect syntax near ",": line 1 col 94 (at pos 94) (v_string := v_string || v_strng;)

Please let me know reasons for this issue.

Appreciate your inputs.

Thanks,

Vasu.