Analytical view

when I am trying to executing query individually its giving error message when I am using same query in procedure its working fine why

SELECT BUKRS,BUTXT,VKORG,VTEXT FROM"_SYS_BIC"."ECCSD/AN_COPA_ACTUAL_DATA"

error msg:

Could not execute 'SELECT BUKRS,BUTXT,VKORG,VTEXT FROM "_SYS_BIC"."ECCSD/AN_COPA_ACTUAL_DATA"' in 6 ms 920 µs .

SAP DBTech JDBC: [7]: feature not supported: not allowed over OLAP VIEW : search without aggregation, grouping by expression other than view column or user defined function with string type

error message telling that its should be group function

when I am trying the following query

SELECT BUKRS,BUTXT,VKORG,VTEXT FROM"_SYS_BIC"."ECCSD/AN_COPA_ACTUAL_DATA"

group by BUKRS,BUTXT,VKORG,VTEXT.                                                                 --> its proving the out put

CE_Funciton - Implemented though procedure

Procedure  declaration as follows

CREATE PROCEDURE PROC_CE_OLAP_VIEW()
AS
BEGIN
TAB1 =  CE_OLAP_VIEW( "_SYS_BIC"."ECCAUG29.SD/AN_COPA_ACTUAL_DATA", [BUKRS,BUTXT,VKORG,VTEXT]);
SELECT * FROM :TAB1;
END;

CALL PROC_CE_OLAP_VIEW()

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When I implemented the same query in procedure with CE_OLAP_VIEW function without grouping columns its working - Why?