Tutorial by Examples: er

Given this data User_IDCompletion_Date12016-07-2012016-07-2122016-07-2022016-07-2122016-07-22 ;with CTE as (SELECT *, ROW_NUMBER() OVER (PARTITION BY User_ID ORDER BY Completion_Date DESC) Row_Num FROM Data) SELECT * FORM CTE WHERE Row_Num <= n Us...

First of all you need to create a class which extends RecyclerView.ItemDecoration : public class SimpleBlueDivider extends RecyclerView.ItemDecoration { private Drawable mDivider; public SimpleBlueDivider(Context context) { mDivider = context.getResources().getDrawable(R.drawable.divider_b...

A counter using an FPGA style flip-flop initialisation: module counter( input clk, output reg[7:0] count ) initial count = 0; always @ (posedge clk) begin count <= count + 1'b1; end A counter implemented using asynchronous resets suitable for ASIC synthesis: module counter...

We start off with $db, an instance of the PDO class. After executing a query we often want to determine the number of rows that have been affected by it. The rowCount() method of the PDOStatement will work nicely: $query = $db->query("DELETE FROM table WHERE name = 'John'"); $count = ...

A true relational database must go beyond throwing data into a few tables and writing some SQL statements to pull that data out. At best a badly designed table structure will slow the execution of queries and could make it impossible for the database to function as intended. A database table shoul...

Apply will be used when when table valued function in the right expression. create a Department table to hold information about departments. Then create an Employee table which hold information about the employees. Please note, each employee belongs to a department, hence the Employee table has ref...

In normal mode, we can increment the nearest number on the line at or after the cursor with <C-a> and decrement it with <C-x>. In the following examples, the cursor position is indicated by ^. Incrementing and decrementing numbers for i in range(11): ^ <C-x> decrements ...

Future<Results> costlyQuery() { var completer = new Completer(); database.query("SELECT * FROM giant_table", (results) { // when complete completer.complete(results); }, (error) { completer.completeException(error); }); // this returns essentially im...

In F#, all functions take exactly one parameter. This seems an odd statement, since it's trivially easy to declare more than one parameter in a function declaration: let add x y = x + y But if you type that function declaration into the F# interactive interpreter, you'll see that its type signat...

Variables can be incremented or decremented by 1 with ++ or --, respectively. They can either precede or succeed variables and slightly vary semantically, as shown below. $i = 1; echo $i; // Prints 1 // Pre-increment operator increments $i by one, then returns $i echo ++$i; // Prints 2 // P...

Given that the function has a proper prototype, integers are widened for calls to functions according to the rules of integer conversion, C11 6.3.1.3. 6.3.1.3 Signed and unsigned integers When a value with integer type is converted to another integer type other than _Bool, if the value can be r...

Pointer conversions to void* are implicit, but any other pointer conversion must be explicit. While the compiler allows an explicit conversion from any pointer-to-data type to any other pointer-to-data type, accessing an object through a wrongly typed pointer is erroneous and leads to undefined beh...

It's fairly common that you may create a class that implements IDisposable, and then derive classes that also contain managed resources. It is recommendeded to mark the Dispose method with the virtual keyword so that clients have the ability to cleanup any resources they may own. public class Paren...

Customer[] customers = Customers.ToArray(); Purchase[] purchases = Purchases.ToArray(); var groupJoinQuery = from c in customers join p in purchases on c.ID equals p.CustomerID into custPurchases select new { CustName = c.Name, custPurchases }; ...

Quantifier operations return a Boolean value if some or all of the elements in a sequence satisfy a condition. In this article, we will see some common LINQ to Objects scenarios where we can use these operators. There are 3 Quantifiers operations that can be used in LINQ: All – used to determine w...

Streams of elements usually do not allow access to the index value of the current item. To iterate over an array or ArrayList while having access to indexes, use IntStream.range(start, endExclusive). String[] names = { "Jon", "Darin", "Bauke", "Hans", "M...

>>> import sys >>> a = object() >>> sys.getrefcount(a) 2 >>> b = a >>> sys.getrefcount(a) 3 >>> del b >>> sys.getrefcount(a) 2

Concatenation refers to the operation of appending one sequence to another. Concat Concatenates two sequences to form one sequence. Method Syntax // Concat var numbers1 = new int[] { 1, 2, 3 }; var numbers2 = new int[] { 4, 5, 6 }; var numbers = numbers1.Concat(numbers2); // number...

Filtering refers to the operations of restricting the result set to contain only those elements that satisfy a specified condition. Where Selects values that are based on a predicate function. Method Syntax // Where var numbers = new int[] { 1, 2, 3, 4, 5, 6, 7, 8 }; var evens = number...

A join of two data sources is the association of objects in one data source with objects that share a common attribute in another data source. Join Joins two sequences based on key selector functions and extracts pairs of values. Method Syntax // Join class Customer { public int Id ...