I was able to prove this with graph-theory. Might want to add that tag in 🙂 Create a graph with n vertices. Create an edge from node n_i to n_j if the element in position i should be in position j in the correct ordering. You will now have a graph consisting of several non-intersecting … Read more
mysequence.CURRVAL returns the latest value that was obtained from sequence mysequence in your session, and hence isn’t defined until you have obtained a value using mysequence.NEXTVAL at least once in the session. The purpose of CURRVAL is to let you use the sequence value more than once in your code e.g. insert into parent (parent_id, … Read more
You can select the current_value from sys.sequences: SELECT current_value FROM sys.sequences WHERE name=”OrderNumberSequence” ; DEMO
I don’t believe you can do it like that but you should be able to use the setval function direction which is what the alter does. select setval(‘sequenceX’, (select max(table_id)+1 from table), false) The false will make it return the next sequence number as exactly what is given.
There is no performance benefit offered by forEach. In fact, if you look at the source code, the forEach function actually simply performing for–in. For release builds, the performance overhead of this function over simply using for–in yourself is immaterial, though for debug builds, it results in an observable performance impact. The main advantage of … Read more
You could just use the same Win32 API function that SQL Server uses: UuidCreateSequential and apply some bit-shifting to put the values into big-endian order. And since you want it in C#: private class NativeMethods { [DllImport(“rpcrt4.dll”, SetLastError=true)] public static extern int UuidCreateSequential(out Guid guid); } public static Guid NewSequentialID() { //Code is released into … Read more
for i in growthRates: fund = fund * (1 + 0.01 * growthRates) + depositPerYear should be: for i in growthRates: fund = fund * (1 + 0.01 * i) + depositPerYear You are multiplying 0.01 with the growthRates list object. Multiplying a list by an integer is valid (it’s overloaded syntactic sugar that allows … Read more
You can temporarily increase the cache size and do one dummy select and then reset the cache size back to 1. So for example ALTER SEQUENCE mysequence INCREMENT BY 100; select mysequence.nextval from dual; ALTER SEQUENCE mysequence INCREMENT BY 1;
sequenceName is the name of the sequence in the DB. This is how you specify a sequence that already exists in the DB. If you go this route, you have to specify the allocationSize which needs to be the same value that the DB sequence uses as its “auto increment”. Usage: @GeneratedValue(generator=”my_seq”) @SequenceGenerator(name=”my_seq”,sequenceName=”MY_SEQ”, allocationSize=1) If … Read more
list.groupBy(_.property).map(_._2.head) Explanation: The groupBy method accepts a function that converts an element to a key for grouping. _.property is just shorthand for elem: Object => elem.property (the compiler generates a unique name, something like x$1). So now we have a map Map[Property, List[Object]]. A Map[K,V] extends Traversable[(K,V)]. So it can be traversed like a list, … Read more