Concatenating to a variable more than once?

Question

Is it possible to concat to the same variable more than once? For some reason I am thinking not.
I have the following:
declare v_sql VARCHAR2(2000);
v_sql := 'Select blah balh Where myfield in (';
if v_show1 = 1 then
v_sql := v_sql || '1,'
end if;
if v_show2 = 1 then
v_sql := v_sql || '2,'
end if;
if v_show3 = 1 then
v_sql := v_sql || '3,'
end if;
v_sql := v_sql || '4)';
Is that possible or is there another way to do this?
Thanks,
Greg

Answer 1

Ok. I thought it was but just checking. Then I guess I have an issue with my procedure below. It doesn't appear to be looking at the v_statuslist as it is empty each time.
CREATE OR REPLACE PROCEDURE USP_REPORTAUDITMETRICDEF(
     v_apprid IN PM_MetricDefData.M_ApprId%TYPE,
     v_startdate IN PM_MetricDefData.AsOfDate%TYPE := NULL,
     v_enddate IN PM_MetricDefData.AsOfDate%TYPE := NULL,
     v_bshowpending IN NUMBER,
     v_bshowapproved IN NUMBER,
     v_bshowrejected IN NUMBER,
     v_bshowprocessed IN NUMBER,
cv_results OUT SYS_REFCURSOR)
IS
     v_sql VARCHAR2(2000);
     v_statuslist VARCHAR2(20) := '';
     v_code VARCHAR2(10);
     v_parentid NUMBER;
BEGIN
     Select M_Code, M_ParentId into v_code, v_parentid From PM_MetricDefApproved
     Where M_ApprId = v_apprid;
     if v_parentid = 0 then
          /* Select parent metric snapshot records */
          v_sql := 'Select MDS.M_Title, MDS.M_Code, MDS.M_Desig, MDS.M_Desc, MDS.M_SuggChgs, MDS.M_Remarks, '
               || 'NVL(LV.ValueDesc, '''') as TypeDesc, MDS.M_ParentId, NVL(LV5.ValueDesc, '''') as UnitDesc, '
               || 'LV6.ValueDesc as M_Compare, MDS.M_AllowDataEntry, MDS.M_VisiblePublic, '
               || 'MDS.M_Weight, NVL(LV2.ValueDesc,'''') as AreaValueDesc, '
               || 'MDS.M_ParaNum, MDS.M_Obj, MDS.M_Thresh, MDS.M_PWSNum, MDS.M_UpperDataLimit, MDS.M_LowerDataLimit, '
               || 'NVL(LV3.ValueDesc,'''') as RptFreqValueDesc, NVL(LV4.ValueDesc,'''') as ColFreqValueDesc, '
               || 'MDS.M_RptProcess, MDS.M_RptMethod, '
               || 'MDS.PS_Level1, MDS.PS_Level2, MDS.PS_Level3, MDS.PS_Level4, MDS.PS_Level5, '
               || 'MDS.AF_Level1, MDS.AF_Level2, MDS.AF_Level3, MDS.AF_Level4, MDS.AF_Level5, '
               || 'AC.ApprovalDesc, '
               || 'MDS.M_CreateDate, NVL(UL.UserName,''<unknown>'') as CreatedUserName '
               || 'From PM_MetricDefSnapshots MDS, '
               || 'PM_ApprovalCodes AC, '
               || 'PM_LookupValues LV6, '
               || 'PM_MetricDefApproved MDA, '
               || 'PM_UserLookup UL, '
               || 'PM_LookupValues LV, '
               || 'PM_LookupValues LV2, '
               || 'PM_LookupValues LV3, '
               || 'PM_LookupValues LV4, '
               || 'PM_LookupValues LV5 '
               || 'Where MDS.M_ApprStatus=AC.ApprovalId '
               || 'and MDS.M_CompareValueId=LV6.ValueId '
               || 'and MDS.M_LinkApprId=MDA.M_ApprId(+) '
               || 'and MDS.M_CreateUserId=UL.UserCAMID(+) '
               || 'and MDS.M_TypeValueId=LV.ValueId(+) '
               || 'and MDS.M_AreaValueId=LV2.ValueId(+) '
               || 'and MDS.M_RptFreqValueId=LV3.ValueId(+) '
               || 'and MDS.M_ColFreqValueId=LV4.ValueId(+) '
               || 'and MDS.M_PSUnitValueId=LV5.ValueId(+) '
               || 'and MDS.M_Code = :code ';
     else
          /* Select child metric snapshot records */
          v_sql := 'Select MDS.M_Title, MDS.M_Code, MDAP.M_Desig, MDAP.M_Desc, MDAP.M_SuggChgs, MDAP.M_Remarks, '
               || 'NVL(LV.ValueDesc, '''') as TypeDesc, MDS.M_ParentId, NVL(LV5.ValueDesc, '''') as UnitDesc, '
               || 'LV6.ValueDesc as M_Compare, MDS.M_AllowDataEntry, MDS.M_VisiblePublic, '
               || 'MDS.M_Weight, NVL(LV2.ValueDesc,'''') as AreaValueDesc, '
               || 'MDAP.M_ParaNum, MDAP.M_Obj, MDAP.M_Thresh, MDAP.M_PWSNum, MDS.M_UpperDataLimit, MDS.M_LowerDataLimit, '
               || 'NVL(LV3.ValueDesc,'''') as RptFreqValueDesc, NVL(LV4.ValueDesc,'''') as ColFreqValueDesc, '
               || 'MDAP.M_RptProcess, MDAP.M_RptMethod, '
               || 'MDAP.PS_Level1, MDAP.PS_Level2, MDAP.PS_Level3, MDAP.PS_Level4, MDAP.PS_Level5, '
               || 'MDAP.AF_Level1, MDAP.AF_Level2, MDAP.AF_Level3, MDAP.AF_Level4, MDAP.AF_Level5, '
               || 'AC.ApprovalDesc, '
               || 'MDS.M_CreateDate, NVL(UL.UserName,''<unknown>'') as CreatedUserName '
               || 'From PM_MetricDefSnapshots MDS, '
               || 'PM_MetricDefApproved MDAP, '
               || 'PM_ApprovalCodes AC, '
               || 'PM_LookupValues LV6, '
               || 'PM_UserLookup UL, '
               || 'PM_LookupValues LV, '
               || 'PM_LookupValues LV2, '
               || 'PM_LookupValues LV3, '
               || 'PM_LookupValues LV4, '
               || 'PM_LookupValues LV5 '
               || 'Where MDS.M_ParentId=MDAP.M_ApprId '
               || 'and MDS.M_ApprStatus=AC.ApprovalId '
               || 'and MDAP.M_CompareValueId=LV6.ValueId '
               || 'and MDS.M_CreateUserId=UL.UserCAMID(+) '
               || 'and MDS.M_TypeValueId=LV.ValueId(+) '
               || 'and MDAP.M_AreaValueId=LV2.ValueId(+) '
               || 'and MDAP.M_RptFreqValueId=LV3.ValueId(+) '
               || 'and MDAP.M_ColFreqValueId=LV4.ValueId(+) '
               || 'and MDAP.M_PSUnitValueId=LV5.ValueId(+) '
               || 'and MDS.M_Code = :code ';
     end if;
     /* if date range was specified, add it to where clause */
     if v_startdate is not null then
          v_sql := v_sql || 'and MDS.M_CreateDate Between :startdate and :enddate ';
     end if;
     /* Determine what status to retrieve */
     if v_bshowpending = 1 then
          v_statuslist := v_statuslist || '0,';
     end if;
     if v_bshowapproved = 1 then
          v_statuslist := v_statuslist || '1,';
     end if;
     if v_bshowrejected = 1 then
          v_statuslist := v_statuslist || '2,';
     end if;
     if v_bshowprocessed = 1 then
          v_statuslist := v_statuslist || '3,';
     end if;
     if substr(v_statuslist, length(v_statuslist)-1,1) = ',' then
          v_statuslist := substr(v_statuslist,1,length(v_statuslist)-1);
     end if;
     if v_statuslist <> '' then
          v_sql := v_sql || ' and MDS.M_ApprStatus in (' || v_statuslist || ')';
     end if;
     v_sql := v_sql || ' Order By MDS.M_CreateDate Desc';
     if v_startdate is not null then
          OPEN cv_results FOR v_sql
               using v_code,
                    v_startdate,
                    v_enddate;
     else
          OPEN cv_results FOR v_sql
               using v_code;
     end if;
END;
/