convert mysql (on duplicate key ) query to oracle merge - mysql

Question

INSERT INTO table1(id,dept_id,name,description,creation_time,modified_time)
VALUES('id','dept_id','name','description','creation_time','modified_time')
ON DUPLICATE KEY UPDATE dept_id=VALUES(dept_id),name=VALUES(name),
description=VALUES(description),creation_time=VALUES(creation_time),
modified_time=VALUES(modified_time)
I used the below oracle to convert the above mysql query. The query fails. Can you please help me figure out what is wrong with the oracle query.
Merge into table1 t1 using
(VALUES ('id','dept_id','name','description','creation_time','modified_time')) as temp
(id,dept_id,name,description,creation_time,modified_time) on t1. id = temp.id
WHEN MATCHED THEN UPDATE SET dept_id=t1.dept_id, description=t1.description, name=t1.name,
creation_time=t1.creation_time, modified_time=t1.modified_time
WHEN NOT MATCHED THEN INSERT (id,dept_id,name,description,creation_time,modified_time)
VALUES ('id','dept_id','name','description','creation_time','modified_time')

Answer 1

To do this, you need to use a table or subquery in the using clause (in your case, you need a subquery).
In Oracle, you can use the dual table if you need to select something without needing to select from an actual table; this is a table that contains only a single row and a single column.
Your merge statement should therefore look something like:
MERGE INTO table1 tgt
USING (SELECT 'id' id,
'dept_id' dept_id,
'name' NAME,
'description' description,
'creation_time' creation_time,
'modified_time' modified_time
FROM dual) src
ON tgt.id = src.id
WHEN MATCHED THEN
UPDATE
SET tgt.dept_id = src.dept_id,
tgt.description = src.description,
tgt.name = src.name,
tgt.creation_time = src.creation_time,
tgt.modified_time = src.modified_time
WHEN NOT MATCHED THEN
INSERT
(tgt.id,
tgt.dept_id,
tgt.name,
tgt.description,
tgt.creation_time,
tgt.modified_time)
VALUES
(src.id,
src.dept_id,
src.name,
src.description,
src.creation_time,
src.modified_time);
Note how the when not matched clause uses the columns from the source subquery, rather than using the literal values you supplied. (I assume that in your actual code, these literal values are actually variables; creation_time is a pretty odd value to store in a column labelled creation_time!).
I've also switched the aliases to make it clearer where you're merging to and from; I find this makes it easier to understand what the merge statement is doing. YMMV.