How to Retrieve Records Containing any value from Set of Values: SQL Programming

List operators, in context of SQL programming, are used to compare a value to a list of literal values that have been specified. When field name must contain one of the values returned by an expression for inclusion in the query result, list operators comes in to existence.

Sometimes, you might want to retrieve data either within a given range or after specifying a set of values to check whether the specified value matches any data of the table. This type of operation is performed by using the IN and NOT IN keywords. The syntax of using the IN and NOT IN operators in the SELECT statement is:

SELECT column_list
FROM table_name
WHERE expression list_operator ('value_list')

Where

• column_list: list of fields to be shown in output.
• table_name: from the records are to be retrieved.
• expression is any valid combination of constants, variables, functions, or column-based expressions.
• list_operator is any valid list operator, IN or NOT IN.
• value_list is the list of values to be included or excluded in the condition.

IN keyword selects values that match any one of the values in a list. The following SQL query retrieves records of employees who are Recruiters or Stockers from the Employee table:

SELECT BusinessEntityID, JobTitle, LoginID FROM HumanResources.Employee WHERE JobTitle IN ('Recruiter', 'Stocker')

NOT IN keyword restricts the selection of values that match any one of the values in a list. The following SQL query retrieves records of employees whose designation is not Recruiter or Stocker:

SELECT BusinessEntityID, JobTitle, LoginID FROM HumanResources.Employee WHERE JobTitle Not IN ('Recruiter', 'Stocker')

Retrieve records matches condition
Retrieve records within given range

How to Retrieve Records that contain values in Given Range: SQL Programming

Criteria is similar to a formula, a string that may consist of field references, operators and constants. We can tagged it an expression in sql programming. Sometimes this criteria have to be in range of values to let the programmer can select records within a range.

The article describes about these range operator that can access records within a given range e.g. list of students between ages 18yr to 25yr, list of employee having salary 10k to 20k. The inputted value may be a number, text or even dates. Mostly these range operator allows you to define a predicate in the form of a scope, if a column value falls in the specified scope, it got selected.

The Range operator retrieves data based on a range. The syntax for using the range operator in the SELECT statement is:

SELECT column_list
FROM table_name
WHERE expression1 range_operator expression2 AND expression3

Where

• Column_list: list of fields to be shown in output.
• Table_name: from the records are to be retrieved.
• expression1, expression2, and expression3 are any valid combination of constants, variables, functions, or column-based expressions.
• Range_operator is any valid range operator.

Here’re the range operators used in Sql programming

BETWEEN: Is used to specify a test range. It gives records specifying the given condition via sql query.
The following SQL query retrieves records from the Employee table when the vacation hour is between 20 and 50:

SELECT BusinessEntityID, VacationHours FROM HumanResources.Employee WHERE VacationHours BETWEEN 20 AND 50

NOT BETWEEN: Is used to specify the test range to which he values in the search result do not belong.
The following SQL query retrieves records from the Employee table when the vacation hour is not between 40 and 50:

SELECT BusinessEntityID, VacationHours FROM HumanResources.Employee WHERE VacationHours Not BETWEEN 20 AND 50

Retrieve records matches condition

Role of Basic Graphical Controls of Programming: Introduction to Java

The Palette tab of a Graphical controls offered by Java Swing contains the tools that you can use to draw controls on your forms/windows/ frames while programming. The area on the frame where GUI components are placed is called content pane.

In earlier article, we have discussed about what are components. You have seen many controls listed on the Swing control palette. Here’s a list with briefly description about role and purpose of some commonly used controls.

• JFrame provides the basic attributes and behavior of a window. A frame is displayed as a separate window with its own tittle bar.
• JLable allows un-editable text (i.e., that user cannot change) or icons to be displayed.
• JTextField allows user input, can also be used to be display text. As it can be edited you can also call it edit field.
• JButton provides button capabilities. An action Event is generated when button is pushed.
• JCheckBox provides check box. Checkboxes are used to allow a user select multiple choices, e.g., a student can select 5 subject out of 17 subject-choices. A check boxes shows an X in box in front of it when selected.
• JList is a list of items from which a selection can be made. From a list, multiple elements can be selected.
• JComboBox provides a drop-down list of items from which a selection can be made or new items can be added. It is a combination of text field and list.
  Note: The area on the frame where GUI components are placed is called content pane.
• JPanel is a supporting container that cannot be displayed on its own but must be added to another container. Panels can be added to the content pane of a frame. They help to organize the components in a GUI.
• JRadioButton provides radio buttons. Radio buttons are option buttons that can be turned on or off. The radio buttons provide mutually exclusive options.

Note: Though radio buttons and checkboxes appear to function similarly, yet there is an important difference-when a radio button is selected, all other radio buttons in its same group are automatically unselected. On the other hand, any no. of checkboxes can be selected.

Computer Programming: Operators in c# console application

Introduction

It is a symbol, which is performed operation on operands, operation can be mathematical or logical. In c#, operators are categories in three basic parts first one is unary operator and second one is binary operator and last one is ternary operator. In unary operator we use single operand like.
++a // here a is a "operand"
In Binary operator we use two operand. Like
a+b;
In ternary operator we use three operand like
a>b?a:b

Assignment Operator (=)

if we create a variable of type integer also we want to initialize it with some value then we should use assignment operator like.

int a=10;

Here, variable a is initialized with value 10. It means you can say the right hand side value is copy to left hand side variable using assignment operator.

Arithmetic Operators ( +,-,*,/,%)

Basically arithmetic operators are used for doing mathematical calculation like addition of two or more numbers , multiplication, division, subtraction, and remainder. lets take a simple example to understand arithmetic operators. If the total collection by five students is five thousand then find the average value?.

int collected_money=5000;

int total_student =5;

int avg=collected_money/total_student;

Ternary operator (?, : )

In ternary operator we have three operands, in which first operand is used for check the condition and other two operands is used for giving results. Let’s take a simple example to understand the ternary operator.

Int firstnumber=10;
Bool result;
Result = firstnumber>10? True: false;

In the preceding example, if condition becomes true or you can say if firstnumber is greater than to 10 then ternary operator gives  ‘true’ in results otherwise gives ‘false’.

 

Comparison Operators (< , > ,<=,>=,!=,==)

using comparison operator you can perform Boolean operation between operands known as comparison operator. Lets take an simple to understand comparison operator

 

 class Program
    {
        static void Main(string[] args)
        {
            int a = 10;
            if (a==10)
            {
                Console.WriteLine(string.Format("The value of variable ={0}", a));
  
            }
            Console .ReadKey (false);
        }
    }
 

Here, condition if check equality operation between operands, a and constant value 10. If condition becomes true, output comes "The value of variable=10".


 

  

  Logical operator (&&,|| )

Perform logical operation between Boolean operands known as logical operator. Lets take a simple example

 

  class Program
    {
        static void Main(string[] args)
        {
            bool a = true;
            bool b = true;

            if (a&&b)
            {
                Console.WriteLine("condition becomes true");
  
            }
            Console .ReadKey (false);
        }
    }

 

JFC, Toolkit and Software Tiers used in GUI Programming: Introduction to JAVA

In JAVA, GUI features are supported via JFC. JFC is short for Java Foundation Classes, which encompass a group of features for building graphical user interfaces (GUI's) and adding rich graphics functionally and interactivity to Java applications. One major feature of JFC is Swing API, which includes everything from buttons to split panes to tables and every other functionally to create a GUI application.

Our later articles will describe, how to build GUI programs using Swing API’s features. The GUI programs that will create in Java will contain three tiers of software.

• Graphical components make up the GUI such as a button or text box or a menu etc. Each graphical components has certain Properties. A property is a characteristic of an object such as its size, colour, title etc. You’ll learn about basics graphical components that Java’s Swing API offers, later in the articles.
• Events Listeners that get notified about the events and respond to them.
• The graphical Event Handler that do the work for the user in case the event occurs.

The graphical components are those like the one listed above. You can use them as they are, or extend them into your own classes. Event listeners are registered with GUI objects. In case of occurrence of an event, the objects notifies its event listeners them invokes event-handler method then executes the Java code written in it.

Java GUI toolkit

You know that a GUI in Java is created with at least three kinds of objects: components, events and listeners. A components is an object that defines a screen elements such as a push button, text field, scroll bar, menu, etc. the components that you can use for creating GUI in Java are available through Swing API.
A component is an object that defines a screen element such as a push button, text field, scroll bar, menu etc.

Types of Graphical Components

The graphical controls that you put in GUI applications are broadly of two types: the Container control and the Child control.

The container is control that can hold other control within it e.g. a Panel (there can be multiple controls inside a Panel) or Panes or simply frame (you can put so many controls on it). Control inside a container are known as a child controls. The child controls can exist completely inside their containers. That means you can’t move them outside their container and if try to drag them beyond and the boundary of their container, part of the control gets hidden. When you delete a container control, all its child controls automatically get deleted.

Do you know that Java GUI programming demands that all swing components s must contained in a container? A GUI application must contain a top-level container that can hold other controls in it.

A control is also known as a widget (short for window gadget). You can think of widget/ control as an element of a GUI that can be seen and that display an information and with user, e.g., a window, text field, frame etc. are widgets.

Graphical Controls of Swing

How to Retrieve Records based on One or More Condition: SQL Programming

Logical operators are used in the SELECT statement to retrieve records based on one or more conditions. While querying data in sql programming, programmer can combine more than one logical operator to apply multiple search conditions. As same as in comparison operator, the conditions specified by the logical operators are connected with the WHERE clause.

The syntax for using the logical operators in the SELECT

SELECT column_list
FROM table_name
WHERE conditional_expression 1 logical operator Conditional_expression 2

Where

• column_list: list of fields to be shown in output.
• table_name: from the records are to be retrieved.
• conditional_expression 1 and conditional_expression 2 are any conditional expressions.
• logical operator: any operator listed below.

Basically there are three types of logical operators in every computer programming. They are Or, And & Not, described below with example.

OR: Return a true value when at least one condition is satisfied. The following SQL query retrieves records from the Department table when the GroupName is either Manufacturing or Quality Assurance:

SELECT * FROM HumanResources.Department WHERE GroupName = 'Manufacturing' OR GroupName = 'Quality Assurance'

AND: Is used to join two conditions and returns a true value when both the conditions are satisfied. For example, to view the details of all the employees of Adventure Works who are married and working as an Engineering Manager, you can use the AND logical operator, as shown in the following SQL query:

SELECT * FROM HumanResources.Employee WHERE Title = 'Engineering Manager' AND MaritalStatus = 'M'

NOT: Reverses the result of the search condition. The following SQL query retrieves records from the Department table when the GroupName is not Manufacturing or Quality Assurance:

SELECT * FROM Humansources.Employee WHERE Title = 'Design Engineer' And NOT MaritalStatus = 'F'

The preceding query retrieves all the rows, except the rows that match the condition specified after the NOT conditional expression.

How to Use Comparison Operators to Specify Conditions: SQL Programming

Comparison operators test whether two expressions are same or not. These operators can be used on all the sql data types except some of them like text, ntext or image. Equal to, greater then, less than are such operators. The article will let you enable to use these operators with examples.

While arithmetic operators are used to calculate column values, Comparison operators test for similarity between two expressions. You can create conditions in the SELECT statement to retrieve selected rows by using various comparison operators. Comparison operators allow row retrieval from a table based on the condition specified in the WHERE clause. Comparison operators cannot be used on text, ntext, or image data type expressions.
The syntax for using the comparison operator in the SELECT statement is:

 SELECT column_list
 FROM table_name
 WHERE expressiona1 comparison_operator expression2

Where

• column_list: list of fields to be shown in output.
• table_name: from the records are to be retrieved.
• expression1 and expression2: any expression on which the operator will be applied.
• comparison_operator: may be one listed below.

The following SQL query retrieves records from the Employee table where the vacation hour is more than 20:
SELECT BusinessEntityID, NationalIDNumber, JobTitle, VacationHours FROM HumanResources.Employee WHERE VacationHours > 20

In the preceding example, the query retrieves all the rows that satisfy the specified condition by using the comparison operator. The result is shown in the following image:

The SQL Server provides the following comparison operators.

• =   Equal to
• >   Greater than
• <   Less than
• >=   Greater than or equal to
• <=   Less than or equal to
• <>   Not equal to
• !=   Not equal to
• !<   Not less than
• !>   Not greater than

Sometimes, you might need to view records for which one or more conditions hold true. Depending on the requirements, you can retrieve records based on the following conditions:

• Records that match one or more conditions
• Records that contain values in a given range
• Records that contain any value from a given set of values
• Records that match a pattern
• Records that contain NULL values
• Records to be displayed in a sequence
• Records from the top of a table
• Records without duplication of values