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478
votes
33answers
492065 views

Fetch the row which has the Max value for a column

Table: UserId, Value, Date. I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL?...
93
votes
7answers
255142 views

ORA-00979 not a group by expression

I am getting ORA-00979 with the following query: SELECT cr.review_sk, cr.cs_sk, cr.full_name, tolist(to_char(cf.fact_date, 'mm/dd/yyyy')) "appt", cs.cs_id, cr.tracking_number from review cr, cs, fact...
216
votes
13answers
509074 views

Update statement with inner join on Oracle

I have a query which works fine in MySQL, but when I run it on Oracle I get the following error: SQL Error: ORA-00933: SQL command not properly ended 00933. 00000 - "SQL command not properly en...
277
votes
16answers
633061 views

How to create id with AUTO_INCREMENT on Oracle?

It appears that there is no concept of AUTO_INCREMENT in Oracle, up until and including version 11g. How can I create a column that behaves like auto increment in Oracle 11g?
735
votes
13answers
933102 views

How do I limit the number of rows returned by an Oracle query after ordering?

Is there a way to make an Oracle query behave like it contains a MySQL limit clause? In MySQL, I can do this: select * from sometable order by name limit 20,10 to get the 21st to the 30th rows (s...
182
votes
7answers
284304 views

SQL JOIN and different types of JOINs

I have been going through many threads on SO and some other forums. So I thought I would summarize "What is SQL JOIN?" and "What are different types of SQL JOINs?".
101
votes
11answers
249148 views

SQL Query to concatenate column values from multiple rows in Oracle

Would it be possible to construct SQL to concatenate column values from multiple rows? The following is an example: Table A PID A B C Table B PID SEQ Desc A 1 Have A 2 ...
21
votes
16answers
112963 views

BadImageFormatException. This will occur when running in 64 bit mode with the 32 bit Oracle client components installed

I am getting this error while on of my .Net application are trying to make a connection to oracle database. The error says that This problem will occur when running in 64 bit mode with the 32 bit Ora...
136
votes
6answers
83669 views

When do I need to use a semicolon vs a slash in Oracle SQL?

We have been having some debate this week at my company as to how we should write our SQL scripts. Background: Our database is Oracle 10g (upgrading to 11 soon). Our DBA team uses SQLPlus in order...
189
votes
10answers
63497 views

Why does Oracle 9i treat an empty string as NULL?

I know that it does consider ' ' as NULL, but that doesn't do much to tell me why this is the case. As I understand the SQL specifications, ' ' is not the same as NULL -- one is a valid datum, and ...

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