Update Rows with info from other Rows in Same Table.

Question

I'm trying to update rows with information from the same table. The table gets loaded with info from a report that runs and it has to be a new entry every month but I would like to carry over some of the info from last month. This statement below runs but updates all rows in the new table load and in my test cases I only made a few match so only like 5 records should get updated. This is an example of what I'm trying to do. If I add this(C2.COL_INVC_ID = C1.COL_INVC_ID) to the last "*Where*" statement I get an invalid identifier for "C2.COL_INVC_ID". So what am I doing wrong here??? How can I update only the rows that where also in last months run???
Thanks in advance for any help!
Update OpenIssues OI1
Set(OI1.Num, OI1.Status, OI1.Code, OI1.LastModifiedDate) =
(Select OI2.Num, OI2.Status, OI2.Code, OI2.LastModifiedDate
From OpenIssues OI2
Where OI2.num = OI1.num and OI2.TableLoadDate = TO_DATE('01/31/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS')
Where and OI1.TableLoadDate = TO_DATE('02/29/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS')
SQLMe

Answer 1

Hi,
Welcome to the forum!
SQLMe wrote:
I'm trying to update rows with information from the same table. The table gets loaded with info from a report that runs and it has to be a new entry every month but I would like to carry over some of the info from last month. This statement below runs but updates all rows in the new table load and in my test cases I only made a few match so only like 5 records should get updated. This is an example of what I'm trying to do. If I add this(C2.COL_INVC_ID = C1.COL_INVC_ID) to the last "*Where*" statement I get an invalid identifier for "C2.COL_INVC_ID". If the aliases c1 and c2 aren't defined anywhere, then you can't use them anywhere.
The WHERE clause of the UPDATE statement can only reference the table being updated, ot1 in this case.
So what am I doing wrong here??? How can I update only the rows that where also in last months run???
Thanks in advance for any help!
Update OpenIssues OI1
Set(OI1.Num, OI1.Status, OI1.Code, OI1.LastModifiedDate) =
(Select OI2.Num, OI2.Status, OI2.Code, OI2.LastModifiedDate
From OpenIssues OI2
Where OI2.num = OI1.num and OI2.TableLoadDate = TO_DATE('01/31/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS')
Where and OI1.TableLoadDate = TO_DATE('02/29/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS')
------------There's a syntax error in the last line. Either something got lost when you posted the code, or you just don't want the keyword AND. You certainly don't want AND immediately after WHERE.
In general, if it's not obvious how to do an UPDATE, then UPDATE is the wrong tool: you want MERGE instead.
Whenever you have a problem, please post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) from all tables involved.
Also post the results you want from that data, and an explanation of how you get those results from that data, with specific examples.
Simplify the problem as much as possible. Remove all tables and columns that play no role in this problem.
If you're asking about a DML statement, such as UPDATE, the CREATE TABLE and INSERT statements should re-create the tables as they are before the DML, and the results will be the contents of the changed table(s) when everything is finished.
Always say which version of Oracle you're using.
See the forum FAQ {message:id=9360002}