Executing SQL queries in SAP-GUI e.g. select * from but000

Question

Hallo,
I am newbie in the SAP world. Is there a way to run select statements from SAP GUI? e.g. I want to know how many rows are returning from a join xyz.
select count() from tabA and tabB where tabA.id = tabB.id and tabA.Name is not null.*
Is it possible with SQVI (SQ01)?
Please help.

Answer 1

Testcase:
SQL> create table scott.testit
     ( id number not null,
       value1 varchar2(10) not null )
     tablespace DATA;
Table created.
SQL> desc scott.testit;
Name       Null?    Type
ID        NOT NULL NUMBER
VALUE1    NOT NULL VARCHAR2(10)
SQL> insert into scott.testit (id,value1) values ( 1, 'Hello' );
1 row created.
SQL> commit;
Commit complete.
SQL> select * from scott.testit;
        ID VALUE1
         1 Hello
ADD COLUMN, the old fashioned way
SQL> alter table scott.testit add  ( ADDFIELD1 varchar2(5) );
Table altered.
SQL> desc scott.testit;
Name        Null?    Type
ID         NOT NULL NUMBER
VALUE1     NOT NULL VARCHAR2(10)
ADDFIELD1           VARCHAR2(5)
SQL> select * from scott.testit where ADDFIELD1 is null;
        ID VALUE1     ADDFI
         1 Hello
Works as expected
Try to get NOT NULL and DEFAULT to work
SQL> alter table scott.testit modify ( ADDFIELD1 NOT NULL );
alter table scott.testit modify ( ADDFIELD1 NOT NULL )
ERROR at line 1:
ORA-02296: cannot enable (SCOTT.) - null values found
SQL> alter table scott.testit modify  ADDFIELD1 default '000';
Table altered.
SQL> alter table scott.testit modify ( ADDFIELD1 NOT NULL );
alter table scott.testit modify ( ADDFIELD1 NOT NULL )
ERROR at line 1:
ORA-02296: cannot enable (SCOTT.) - null values found
No suprise so far. You would usually need to update all NOT NULL
values to some values and you would be able to enable the NOT NULL constraint
allthough this may run for quite a while on big tables.
Now lets try the new stuff
SQL> alter table scott.testit drop column ADDFIELD1;
Table altered.
SQL> alter table scott.testit ADD ADDFIELD1 varchar2(3) DEFAULT '000' not null;
Table altered.
SQL> desc scott.testit
Name        Null?    Type
ID         NOT NULL NUMBER
VALUE1     NOT NULL VARCHAR2(10)
ADDFIELD1  NOT NULL VARCHAR2(3)     <<<< BING !!!
SQL> select * from scott.testit;
        ID VALUE1     ADD
         1 Hello      000            <<<< Default '000' is working
SQL> select * from scott.testit where ADDFIELD1 is NULL;
no rows selected                     <<<< NOW this might be suprising
SQL> insert into scott.testit (id,value1,addfield1) values (2,'Bye', '000');
1 row created.
SQL> commit;                         <<<< Trying to compare "real" '000' with DEFAULT '000'
Commit complete.
SQL> select * from scott.testit;
        ID VALUE1     ADD
         1 Hello      000            <<<< Added with default
         2 Bye        000            <<<< inserted as '000'
SQL> alter table scott.testit modify ADDFIELD1 default '111';
Table altered.
SQL> select * from scott.testit;     <<<< Now it gets exciting
        ID VALUE1     ADD
         1 Hello      000            <<<< WOA... How does this work?
         2 Bye        000
SQL> set longC 20000 long 20000
SQL> select dbms_metadata.get_ddl('TABLE','TESTIT','SCOTT') from dual;
DBMS_METADATA.GET_DDL('TABLE','TESTIT','SCOTT')
CREATE TABLE "SCOTT"."TESTIT"
(  "ID" NUMBER NOT NULL ENABLE,
    "VALUE1" VARCHAR2(10) NOT NULL ENABLE,
    "ADDFIELD1" VARCHAR2(3) DEFAULT '111' NOT NULL ENABLE           <<<< No '000' DEFAULT
) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE "DATA"
SQL>
Looks like Oracle is at least a whole lot more clever than I expected.
It must have stored the first Default value somewhere else, as the documentation
says, that the effective rows will NOT be updated (otherwise it would never work so fast).
I need to dig into how datablocks are dumped and read.
Just to finalize this:
SQL> alter table scott.testit modify ADDFIELD1 NULL;
Table altered.
SQL> select * from scott.testit;
        ID VALUE1     ADD
         1 Hello      000
         2 Bye        000
SQL> select * from scott.testit where addfield1 is null;
no rows selected
SQL>
So the change persists even if you revert the constraint allthough the data
should not been changed. Surely need to do a datablock dump of this.
Need to do additional tests with indexes.
But right now I am running out of time.
May be someone else likes to join the expedition.
Volker