Examples of usage in Oracle Merge into

Role: Merge into solution with B table and new a table data, if a table does not, then the B table data into a table;

Grammar:

MERGE into [Your table-name] [rename your table-here]

using ([Write your query here]) [rename your query-sql and using just like a table]

On ([conditional expression here] and [...] ... ）

When mathed THEN [here you can execute some update SQL or something else]

When isn't mathed THEN [execute something else here!]

-------instance-------

Merge into a

Using (select Id,name from B) c

On (a.id=c.id)

When matched then update set A.name=c.name

When not matched then insert (a.id,a.name) values (c.id,c.name);

Role: Use table B with new Table A, if the condition is a.id=b.id, if data in table A does not have that condition inserted.

If you have a large amount of data, this SQL efficiency is very high.

Author: 51cto Blog Oracle Little Bastard

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