What are cursors used for Cursors are often used to highlight text or objects on the screen so that they can be selected. For example, in a word processor, the cursor can be used to select text, format it, and insert new text. Users control cursors with input devices such as mice, touchpads and trackballs.A cursor keeps track of the position in the result set, and allows you to perform multiple operations row by row against a result set, with or without returning to the original table. In other words, cursors conceptually return a result set based on tables within the databases.The "Pointer" or "Mouse Pointer": It is the graphical object that moves on screen. It can be static or animated. The "Cursor": It is the file or the memory block used to encode and save the animated (ANI) or static (CUR) graphical object.
Why is cursor control keys used : The cursor control keys are largely used for the purpose of navigating through documents or for playing games. Before the mouse was invented, the use of cursor control keys was the only way to navigate. As such, several combinations of keys were prevalent, depending on the keyboard layout in use.
Should I use a cursor
Therefore, you should use cursors and loops sparingly, and only when set-based operations are not feasible or efficient.
What is the difference between a pointer and a cursor : The "Pointer" or "Mouse Pointer": It is the graphical object that moves on screen. It can be static or animated. The "Cursor": It is the file or the memory block used to encode and save the animated (ANI) or static (CUR) graphical object.
A cursor is a graphical element on your computer screen that shows your position in a software interface. Typically, it's represented by a blinking vertical line in text editors or a pointer arrow on your desktop.
The "Pointer" or "Mouse Pointer": It is the graphical object that moves on screen. It can be static or animated. The "Cursor": It is the file or the memory block used to encode and save the animated (ANI) or static (CUR) graphical object.
What are the three advantages of cursors
Advantages
- Cursors can be faster than a while loop but they do have more overhead.
- It is we can do RowWise validation or in other way you can perform operation on each Row. It is a Data Type which is used to define multi-value variable.
- Cursors can be faster than a while loop but at the cost of more overhead.
Disadvantages of Cursor in SQL
Cursors in SQL have certain disadvantages that developers should consider when using them: Performance Overhead: Cursors can incur significant performance overhead, especially with large result sets, as individual fetch operations can be time-consuming.A pointer cursor looks like a hand with the index finger extended (pointing). It was historically only used when hovering over links but is now frequently used for any clickable element, such as buttons.
Physically moving the mouse moves the graphic pointer (also referred to as the cursor) on the screen. The pointer has a variety of shapes to indicate its current behavior. Mouse devices often have a primary button (usually the left button), a secondary button (usually the right), and a mouse wheel between the two.
Why use cursor instead of SELECT : Cursors enable an application to retrieve and manipulate individual rows without the restriction of the select loop. Within a select loop, statements cannot be issued that access the database. Use cursors in the following situations: When a program needs to scan a table to update or delete rows.
Why do we need database cursor : In computer science, a database cursor is a mechanism that enables traversal over the records in a database. Cursors facilitate subsequent processing in conjunction with the traversal, such as retrieval, addition and removal of database records.
Why should you avoid cursor
Cursors are used to fetch single rows from the result set returned by a query and allow the row-by-row iteration through the result set, whereas set based processing can be much faster. Cursors can also cause transactional problems because of the run time.
The earliest known written use of the term mouse or mice in reference to a computer pointing device is in Bill English's July 1965 publication, "Computer-Aided Display Control". This likely originated from its resemblance to the shape and size of a mouse, with the cord resembling its tail.In SQL procedures, a cursor make it possible to define a result set (a set of data rows) and perform complex logic on a row by row basis. By using the same mechanics, an SQL procedure can also define a result set and return it directly to the caller of the SQL procedure or to a client application.
What is the purpose of using cursor in SQL : In SQL procedures, a cursor make it possible to define a result set (a set of data rows) and perform complex logic on a row by row basis. By using the same mechanics, an SQL procedure can also define a result set and return it directly to the caller of the SQL procedure or to a client application.