Question about Merge Statement

Question

Is it possible to use a CASE statement inside the update clause of a merge statement? Also what about a function?
I have a string (In Source) that needs to be split into multiple columns (In Target) depending on values in other columns (In Source).
I am on 11iR1

Answer 1

Hi Chris,
You can take a look at the below examples :
SQL>create table t_test
col1,col2,col3
) as
select 1,2,3 from dual union all
select 2,3,4 from dual union all
select 3,4,2 from dual union all
select 9,10,12 from dual union all
select 11,23,43 from dual
create table succeeded.
SQL>select * from t_test;
COL1                   COL2                   COL3                  
1                      2                      3                     
2                      3                      4                     
3                      4                      2                     
9                      10                     12                    
11                     23                     43    
SQL>merge INTO t_test t_t USING
  SELECT
    1 AS col1
  FROM
    dual
) d_d
ON
(d_d.col1 = t_t.col1)
WHEN matched THEN
  UPDATE set
    col2 = (
      CASE
        WHEN d_d.col1 = 1
        THEN 123
        ELSE -1
      END );
1 rows merged
SQL>select * from t_test;
COL1                   COL2                   COL3                  
1                      123                    3                     
2                      3                      4                     
3                      4                      2                     
9                      10                     12                    
11                     23                     43