Converting a dynamic query to use bind variables in Oracle 11g - oracle

Question

I have a dynamic search query that I would like to convert to make use of bind variables. The dynamic portion of the of query is in the where clause, and using a series of if statements to build a string that is concatenated to the rest of the query string. That query is then used in the for clause of a openstatement, which the result set is the return parameter. I'm not really sure how to accomplish this.
Here is the stored procedure:
PROCEDURE run_search(i_unit_id IN lu_unit.fsu_id%TYPE,
i_equipment IN tbl_component.component%TYPE,
i_equipment_status IN tbl_component.equipment_status%TYPE,
i_equipment_type IN tbl_component.equipment_type%TYPE,
i_equipment_subtype IN tbl_component.equipment_sub_type%TYPE,
i_system_id IN tbl_component.system_id%TYPE,
i_association_code IN tbl_component_assc_code.assc_code%TYPE,
i_manufacturer IN lu_component_manu_model.equipment_manufacturer%TYPE,
i_manumodel IN lu_component_manu_model.equipment_model%TYPE,
o_results OUT sys_refcursor) AS
v_query VARCHAR2(32767) := '';
v_where VARCHAR2(32767) := ' 1= 1';
BEGIN
IF i_unit_id IS NOT NULL THEN
v_where := v_where || ' AND unit_id=''' || i_unit_id ||''' ';
END IF;
IF i_equipment IS NOT NULL THEN
v_where := v_where || ' AND lower(component) LIKE ''%' || lower(i_equipment) ||'%'' ';
END IF;
IF i_equipment_status IS NOT NULL THEN
v_where := v_where || ' AND equipment_status=''' || i_equipment_status ||''' ';
END IF;
IF i_equipment_type IS NOT NULL THEN
v_where := v_where || ' AND equipment_type=''' || i_equipment_type ||''' ';
END IF;
IF i_equipment_subtype IS NOT NULL THEN
v_where := v_where || ' AND equipment_sub_type=''' || i_equipment_subtype ||''' ';
END IF;
IF i_system_id IS NOT NULL THEN
v_where := v_where || ' AND system_id=''' || i_system_id || ''' ';
END IF;
IF i_association_code IS NOT NULL THEN
v_where := v_where || ' AND EXISTS ( select null from tbl_component_assc_code where assc_code = ''' || i_association_code || ''' and component_id = vcs.component_id )';
END IF;
IF i_manufacturer IS NOT NULL THEN
v_where := v_where || ' AND equipment_manufacturer=''' || i_manufacturer || ''' ';
END IF;
IF i_manuModel IS NOT NULL THEN
v_where := v_where || ' AND equipment_model=''' || i_manuModel || ''' ';
END IF;
v_query :=
' SELECT rownum, results.* '
||' FROM '
||' ( SELECT '
||' count(*) OVER () ' || ' as total_results, '
||''
||' site_id, site_display_name, '
||' unit_id, unit_display_name, '
||' system_id, system_display_name, '
||' component_id, component, component_description, equipment_description, '
||' equipment_status, equipment_model, equipment_serial_number, equipment_type, equipment_sub_type, '
||' template_ids '
||''
||' FROM vw_component_search '
||' WHERE ' || v_where
||' ORDER BY unit_display_name, component '
||' ) results '
;
OPEN o_results FOR v_query;
END run_search;

Answer 1

You can write the query without dynamically creating it so you include all the parameters and just ignore those which are NULL (please profile it to test whether there are any performance issues compared to a dynamic query):
PROCEDURE run_search(i_unit_id IN lu_unit.fsu_id%TYPE,
i_equipment IN tbl_component.component%TYPE,
i_equipment_status IN tbl_component.equipment_status%TYPE,
i_equipment_type IN tbl_component.equipment_type%TYPE,
i_equipment_subtype IN tbl_component.equipment_sub_type%TYPE,
i_system_id IN tbl_component.system_id%TYPE,
i_association_code IN tbl_component_assc_code.assc_code%TYPE,
i_manufacturer IN lu_component_manu_model.equipment_manufacturer%TYPE,
i_manumodel IN lu_component_manu_model.equipment_model%TYPE,
o_results OUT sys_refcursor)
AS
BEGIN
OPEN o_results FOR
SELECT rownum,
results.*
FROM ( SELECT count(*) OVER () as total_results,
site_id,
site_display_name,
unit_id,
unit_display_name,
system_id,
system_display_name,
component_id,
component,
component_description,
equipment_description,
equipment_status,
equipment_model,
equipment_serial_number,
equipment_type,
equipment_sub_type,
template_ids
FROM vw_component_search
WHERE ( i_unit_id IS NULL
OR unit_id= i_unit_id )
AND ( i_equipment IS NULL
OR lower(component) LIKE '%' || lower(i_equipment) || '%' )
AND ( i_equipment_status IS NULL
OR equipment_status= i_equipment_status )
AND ( i_equipment_type IS NULL
OR equipment_type= i_equipment_type )
AND ( i_equipment_subtype IS NULL
OR equipment_sub_type= i_equipment_subtype )
AND ( i_system_id IS NULL
OR system_id= i_system_id )
AND ( i_association_code IS NULL
OR EXISTS ( select null
from tbl_component_assc_code
where assc_code = i_association_code
and component_id = vcs.component_id ) )
AND ( i_manufacturer IS NULL
OR equipment_manufacturer= i_manufacturer )
AND ( i_manuModel IS NULL
OR equipment_model= i_manuModel )
ORDER BY unit_display_name, component
) results;
END run_search;
(I've not compiled the above code - so there may be some errors).

Answer 2

The best way is to avoid such headache at all. 'SP returning resultset' is a usual practise in a poor legacy things such as MSSQL2000, but in unnecessary and doubtful in Oracle.
If you wish to do this, I'd advice you to do something like this:
procedure MakeGarbage(value_mask varchar2) return sys_refcursor is
cur integer;
stmt varchar2(32000 byte);
type TParamTable is table of varchar2(1000) index by varchar2(20);
params TParamTable;
i varchar2(20);
begin
stmt := 'select * from table where 1 = 1 ';
if value_mask is not null then
stmt := stmt || ' and value like :value_mask ';
params('value_mask') := value_mask;
end if;
...
cur := dbms_sql.create_cursor;
dbms_sql.open_cursor(cur, stmt, dbms_sql.native);
i := params.first;
while i is not null loop
dbms_sql.bind_variable(i, params(i));
i := params.next(i);
end loop;
return dbms_sql.to_ref_cursor(cur);
end;

Answer 3

every reference to a PL/SQL variable is in fact a bind variable.
you can check this asktom link
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:2320123769177
and check "Dynamic SQL" from this link http://www.akadia.com/services/ora_bind_variables.html