Question

I have query building plsql code. I use bind variables and associative array to store their values. Something like that:

declare
    type myt table of varchar2(4000) index by varchar2(100);
    vars myt;
    v_cursor integer;
    newQuery varchar2(1000) := 'select * from blabla where ';
    bind_key varchar2(100);
    rows_count integer;
begin
    -- query building
    if 1=1 then
        newQuery := newQuery || 'col1 = :bind_col1';
        vars(':bind_col1') := sysdate; -- problem!!!
    end if;
    ....
    -- query execution
    v_cursor := dbms_sql.open_cursor;
    dbms_sql.parse(v_cursor, newQuery, dbms_sql.v7);
    bind_key := vars.first;
    loop
        exit when bind_key is null;
        dbms_sql.bind_variable(v_cursor, bind_key, vars(bind_key));
        bind_key := vars.next(bind_key);
    end loop;
    row_count := dbms_sql.execute(v_cursor);
    dbms_sql.close_cursor(v_cursor);
end;

Are there any more generic type than varchar2, so there will not be conversion date->varchar2->date?

Answer 1

dbms_sql.bind_variable can bind variables of many datatypes. You can’t however declare a table of <any_data_type> (which would be logically equivalent to something like Object[] in java for example.)

When you’re working with VARCHAR2 you can use bijective explicit conversion, for example:

newQuery := newQuery || 'col1 = to_date(:bind_col1, ''yyyymmdd hh24:mi:ss'')';
vars(':bind_col1') := to_char(sysdate, 'yyyymmdd hh24:mi:ss');