For tasks you could try to start from
SELECT inv_investments.name Project
,inv_investments.code ProjectCode
,PRJ_BASELINES.NAME Baseline
,PRJ_BASELINES.CODE BaselineCode
-- ,PRJ_BASELINE_DETAILS.BASELINE_ID
,PRJ_BASELINE_DETAILS.ID BASELINE_DET_ID
,PRJ_BASELINE_DETAILS.OBJECT_ID TASKID
-- ,PRJ_BASELINE_DETAILS.OBJECT_TYPE
,PRTASK.PRNAME TASK
,PRTASK.PREXTERNALID TASKCODE
-- ,PRJ_BASELINE_DETAILS.USAGE_SUM
-- ,PRJ_BASELINE_DETAILS.COST_SUM
,PRJ_BASELINE_DETAILS.START_DATE
/* ,PRJ_BASELINE_DETAILS.FINISH_DATE
,PRJ_BASELINE_DETAILS.DURATION
,PRJ_BASELINE_DETAILS.PREXTENSION
,PRJ_BASELINE_DETAILS.MSP_DIRTY
,PRJ_BASELINE_DETAILS.CREATED_DATE
,PRJ_BASELINE_DETAILS.CREATED_BY
,PRJ_BASELINE_DETAILS.LAST_UPDATED_DATE
,PRJ_BASELINE_DETAILS.LAST_UPDATED_BY
,PRJ_BASELINE_DETAILS.IS_CURRENT
,PRJ_BASELINE_DETAILS.SLICE_STATUS
,PRJ_BASELINE_DETAILS.EVM_MR_SUM
,PRJ_BASELINE_DETAILS.EVM_UB_SUM
,PRJ_BASELINE_DETAILS.EVM_BURDEN_FEE
,PRJ_BASELINE_DETAILS.EVM_BURDEN_COM
,PRJ_BASELINE_DETAILS.EVM_BURDEN_GA
,PRJ_BASELINE_DETAILS.EVM_BURDEN_OVHD */
FROM c8.niku.PRJ_BASELINE_DETAILS
,c8.niku.PRJ_BASELINES
,c8.niku.inv_investments
,c8.niku.PRTASK
Where PRJ_BASELINE_DETAILS.BASELINE_ID = PRJ_BASELINES.ID
AND PRJ_BASELINES.PROJECT_ID = inv_investments.id
AND PRJ_BASELINE_DETAILS.OBJECT_TYPE = 'TASK'
AND PRJ_BASELINE_DETAILS.OBJECT_ID= PRTASK.PRID
Martti K.