Skip to main content

Featured Post

How to use Tabs in ASP.NET CORE

I want to show Components in a tabs , so first of all create few components. In this project we have three components, First View Component  public class AllViewComponent : ViewComponent     {         private readonly UserManager<ApplicationUser> _userManager;         public AllViewComponent(UserManager<ApplicationUser> userManager)         {             _userManager = userManager;         }         public async Task<IViewComponentResult> InvokeAsync()         {             List<StudentViewModel> allUsers = new List<StudentViewModel>();             var items = await _userManager.Users.ToListAsync();             foreach (var item in items)             {                 allUsers.Add(new StudentViewModel {Id=item.Id, EnrollmentNo = item.EnrollmentNo, FatherName = item.FatherName, Name = item.Name, Age = item.Age, Birthdate = item.Birthdate, Address = item.Address, Gender = item.Gender, Email = item.Email });             }            

How to Perform Grouping of Data Matching a Criteria: SQL Programming

At times, you need to view data matching specific criteria to be displayed together in the result set. For example, you want to view a list of all the employees with details of employees of each department displayed together.

Grouping can be performed by following clauses:

GROUP BY

The GROUP BY clause summarizes the result set into groups as defined in the query by using aggregate functions. The HAVING clause further restricts the result set to produce the data based on a condition. The syntax of the GROUP BY clause is:

SELECT column_list
FROM table_name
WHERE condition
[GROUP BY [ALL] expression [, expression]
[HAVING search_condition]

Where,
  • ALL is a keyword used to include those groups that do not meet the search condition.
  • expression specifies the column name(s) or expression(s) on which the result set of the SELECT statement is to be grouped.
  • search_condition is the conditional expression on which the result is to be produced.
The following SQL query returns the minimum and maximum values of vacation hours for the different types of titles when the vacation hours are greater than 20:

SELECT JobTitle, Minimum = min (VacationHours), Maximum = max (VacationHours)
FROM HumanResources.Employee
WHERE VacationHours > 20 GROUP BY JobTitle

Outputs:

How to Perform Grouping of Data Matching a Criteria: SQL Programming

The GROUP BY ……..HAVING clause is same as the SELECT….WHERE clause. The result set produced with the GROUP BY clause eliminates all the records and values that do not meet the condition specified in the HAVING clause. The GROUP BY clause collects data that matches the condition, and summarizes it into an expression to produce a single value for each group. The HAVING clause eliminates all those groups that do not match the condition.

The following SQL query retrieves all the titles along with their average vacation hours when the vacation hours are more than 30 and the group average value is greater than 55:

SELECT Title, ‘Average Vacation Hours’ = avg (VacationHours) FROM HumanResources.Employee WHERE VacationHours > 30 GROUP BY Title HAVING avg (VacationHours) >55

The ALL keyword of the GROUP BY clause is used to display all groups, including those which are excluded by the WHERE clause. The ALL keyword is meaningful to those queries that contain the WHERE clause. If ALL is not used, the GROUP BY clause does not show the groups for which there are no matching rows. However, the GROUP BY ALL shows all rows, even if the groups have no rows meeting the search conditions.

The following SQL query retrieves the records for the employee titles that are eliminated in the WHERE condition:

SELECT Title, VacationHours = sum (VacationHours) FROM HumanResources.Employee WHERE Title IN (‘Recruiter’, ‘Stocker’,’Design Engineer’) GROUP BY ALL Title

Comments

Popular Post

Polynomial representation using Linked List for Data Structure in 'C'

Polynomial representation using Linked List The linked list can be used to represent a polynomial of any degree. Simply the information field is changed according to the number of variables used in the polynomial. If a single variable is used in the polynomial the information field of the node contains two parts: one for coefficient of variable and the other for degree of variable. Let us consider an example to represent a polynomial using linked list as follows: Polynomial:      3x 3 -4x 2 +2x-9 Linked List: In the above linked list, the external pointer ‘ROOT’ point to the first node of the linked list. The first node of the linked list contains the information about the variable with the highest degree. The first node points to the next node with next lowest degree of the variable. Representation of a polynomial using the linked list is beneficial when the operations on the polynomial like addition and subtractions are performed. The resulting polynomial can also

How to use Tabs in ASP.NET CORE

I want to show Components in a tabs , so first of all create few components. In this project we have three components, First View Component  public class AllViewComponent : ViewComponent     {         private readonly UserManager<ApplicationUser> _userManager;         public AllViewComponent(UserManager<ApplicationUser> userManager)         {             _userManager = userManager;         }         public async Task<IViewComponentResult> InvokeAsync()         {             List<StudentViewModel> allUsers = new List<StudentViewModel>();             var items = await _userManager.Users.ToListAsync();             foreach (var item in items)             {                 allUsers.Add(new StudentViewModel {Id=item.Id, EnrollmentNo = item.EnrollmentNo, FatherName = item.FatherName, Name = item.Name, Age = item.Age, Birthdate = item.Birthdate, Address = item.Address, Gender = item.Gender, Email = item.Email });             }            

Memory representation of Linked List Data Structures in C Language

                                 Memory representation of Linked List              In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.                Suppose first node of linked list is allocated with an address 1008. Its graphical representation looks like the figure shown below:       Suppose next node is allocated at an address 506, so the list becomes,   Suppose next node is allocated with an address with an address 10,s the list become, The other way to represent the linked list is as shown below:  In the above representation the data stored in the linked list is “INDIA”, the information part of each node contains one character. The external pointer root points to first node’s address 1005. The link part of the node containing information I contains 1007, the address of