How to set time to a date object in java

Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR_OF_DAY,17);
cal.set(Calendar.MINUTE,30);
cal.set(Calendar.SECOND,0);
cal.set(Calendar.MILLISECOND,0);
Date d = cal.getTime();

Also See

• Joda time
• Calendar doc

http://stackoverflow.com/questions/5165428/how-to-set-time-to-a-date-object-in-java

Oracle “Partition By” Keyword

The PARTITION BY clause sets the range of records that will be used for each "GROUP" within the OVER clause.
In your example SQL, DEPT_COUNT will return the number of employees within that department for every employee record. (It is as if your de-nomalising the emp table; you still return every record in the emp table.)

emp_no  dept_no  DEPT_COUNT1       10       3
2       10       3
3       10       3 <- three because there are three "dept_no = 10" records4       20       2
5       20       2 <- two because there are two "dept_no = 20" records

If there was another column (e.g., state) then you could count how many departments in that State.
It is like getting the results of a GROUP BY (SUM, AVG, etc.) without the aggregation of the result set.
It is useful when you use the LAST OVER or MIN OVER functions to get, for example, the lowest and highest salary in the department and then use that in a calulation against this records salary without a sub select. It is also much faster.
Read the linked AskTom article for further details.
Hope this helps.

http://stackoverflow.com/questions/561836/oracle-partition-by-keyword

sql 2005 - The column was specified multiple times

The problem, as mentioned, is that you are selecting PEID from two tables, the solution is to specify which PEID do you want, for example

 SELECT tb.*
    FROM (
        SELECT tb1.PEID,tb2.col1,tb2.col2,tb3.col3 --, and so on
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID
    ) AS tb;

That aside, as Chris Lively cleverly points out in a comment the outer SELECT is totally superfluous. The following is totally equivalent to the first.

        SELECT tb1.PEID,tb2.col1,tb2.col2,tb3.col3 --, and so on
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID

or even

        SELECT * 
        FROM vCodesWithPEs as tb1 INNER JOIN vDeriveAvailabilityFromPE as tb2
        ON tb1.PROD_PERM = tb2.PEID 
        INNER JOIN PE_PDP tb3 ON tb1.PROD_PERM = tb3.PEID

but please avoid using SELECT * whenever possible. It may work while you are doing interactive queries to save typing, but in production code never use it.

http://stackoverflow.com/questions/1058606/sql-2005-the-column-was-specified-multiple-times

What does the 'Z' mean in Unix timestamp '120314170138Z'?

Yes. 'Z' stands for Zulu time, which is also GMT and UTC.
From http://en.wikipedia.org/wiki/Coordinated_Universal_Time:

The UTC time zone is sometimes denoted by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time.

Technically, because the definition of nautical time zones is based on longitudinal position, the Z time is not exactly identical to the actual GMT time 'zone'. However, since it is primarily used as a reference time, it doesn't matter what area of Earth it applies to as long as everyone uses the same reference.
From wikipedia again, http://en.wikipedia.org/wiki/Nautical_time:

Around 1950, a letter suffix was added to the zone description, assigning Z to the zero zone, and A–M (except J) to the east and N–Y to the west (J may be assigned to local time in non-nautical applications; zones M and Y have the same clock time but differ by 24 hours: a full day). These were to be vocalized using a phonetic alphabet which pronounces the letter Z as Zulu, leading sometimes to the use of the term "Zulu Time". The Greenwich time zone runs from 7.5°W to 7.5°E longitude, while zone A runs from 7.5°E to 22.5°E longitude, etc.

  http://stackoverflow.com/questions/9706688/what-does-the-z-mean-in-unix-timestamp-120314170138z

How to Turn on IDENTITY_INSERT in SQL Server 2008?

Via SQL as per MSDN

SET IDENTITY_INSERT sometableWithIdentity ON
INSERT sometableWithIdentity (IdentityColumn, col2, col3, ...)
VALUES (AnIdentityValue, col2value, col3value, ...)
SET IDENTITY_INSERT sometableWithIdentity OFF

The complete error message tells you exactly what is wrong...

Cannot insert explicit value for identity column in table 'sometableWithIdentity' when IDENTITY_INSERT is set to OFF.

 http://stackoverflow.com/questions/7063501/how-to-turn-on-identity-insert-in-sql-server-2008

Can foreign key constraints be temporarily disabled using T-SQL?

If you want to disable all constraints in the database just run this code:

-- disable all constraints
EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"

To switch them back on, run: (the print is optional of course and it is just listing the tables)

-- enable all constraints
exec sp_msforeachtable @command1="print '?'", @command2="ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all"

I find it useful when populating data from one database to another. It is much better approach than dropping constraints. As you mentioned it comes handy when dropping all the data in the database and repopulating it (say in test environment).
If you are deleting all the data you may find this solution to be helpful.
Also sometimes it is handy to disable all triggers as well, you can see the complete solution here.

http://stackoverflow.com/questions/159038/can-foreign-key-constraints-be-temporarily-disabled-using-t-sql

circular foreign key. How do i handle them?

Circular foreign keys are not really supported in SQL Server. It is possible to do it if you really want but it's not very useful since you've have no way to insert any data - you can't insert into table A because the required references in table B don't exist and vice versa. The only way would be to create one of the tables without the FK and then add it after the second table is created. Then, to insert data, you'd need to disable one of the FKs and then re-enable it but this is a very resource intensive operation if you've lots of data since it will all need to be re-checked when the FK is re-enabled. Basically, you either have to live with incomplete declarative referential integrity or, perhaps more wisely, consider remodelling your data as @munisor suggests. WARNING: the following code smaple demonstrates how to create circular FKs but this really is very bad for your health! I'm sure that in the longer run, you won't be wanting to do this. For example, simply trying to drop either of these tables after this is run is very difficult, you can't simple DROP TABLE! CREATE TABLE [A] (     [AId] int         NOT NULL         PRIMARY KEY,     [BId] int         NULL         -- You can't create the reference to B here since it doesn't yet exist! ) CREATE TABLE [B] (     [BId] int         NOT NULL         PRIMARY KEY,     [AId] int         NOT NULL         FOREIGN KEY             REFERENCES [A] ) -- Now that B is created, add the FK to A ALTER TABLE [A]     ADD         FOREIGN KEY ( [BId] )         REFERENCES [B] ALTER TABLE [A]     ALTER COLUMN [BId]         int         NOT NULL

http://stackoverflow.com/questions/2864237/circular-foreign-key-how-do-i-handle-them