What is cursor in SQL?

Cursor is a Temporary Memory or Temporary Work Station. It is Allocated by Database Server at the Time of Performing DML(Data Manipulation Language) operations on Table by User. Cursors are used to store Database Tables. There are 2 types of Cursors: Implicit Cursors, and Explicit Cursors.

What is cursor in SQL with example?

A SQL cursor is a database object that retrieves data from result sets one row at a time. The cursor in SQL can be used when the data needs to be updated row by row. A SQL cursor is a database object that is used to retrieve data from a result set one row at a time.

What is the purpose of 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.

What is cursor and its use?

A cursor contains information on a select statement and the rows of data accessed by it. This temporary work area is used to store the data retrieved from the database, and manipulate this data. A cursor can hold more than one row, but can process only one row at a time.

What is cursor in query?

Cursors are used by database programmers to process individual rows returned by database system queries. Cursors enable manipulation of whole result sets at once. In this scenario, a cursor enables the sequential processing of rows in a result set.

SQL Cursors - how and when to use them

What is cursor and trigger in SQL?

A cursor is activated and thus created in response to any SQL statement. A trigger is executed in response to a DDL statement, DML statement or any database operation.

What is cursor short answer?

1) A cursor is the position indicator on a computer display screen where a user can enter text. In an operating system with a graphical user interface (GUI), the cursor is also a visible and moving pointer that the user controls with a mouse, touch pad, or similar input device.

What is a cursor in MySQL?

MySQL cursor is a kind of loop facility given to traverse in the result of SQL one by one. We can operate on every result by using the cursor in MySQL. Cursors are supported in stored procedures, functions, and triggers only. MySQL cursor is available from version 5 or greater.

What is SQL Indexing?

A SQL index is used to retrieve data from a database very fast. Indexing a table or view is, without a doubt, one of the best ways to improve the performance of queries and applications. A SQL index is a quick lookup table for finding records users need to search frequently.

What is the advantage of cursor in SQL Server?

Cursors can provide the first few rows before the whole result set is assembled. Without using cursors, the entire result set must be delivered before any rows are displayed by the application. So using cursor, better response time is achieved.

Why is cursor required?

Cursor is a named private SQL area from where information can be accessed. Cursors are required to process rows individually for queries returning multiple rows.

What are the types of cursor in SQL?

What is trigger in SQL?

A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT, UPDATE, or DELETE statements on a table or view.

What is a cursor and index in SQL?

In SQL, a cursor can be defined as a tool used widely to define a particular set of results. This result can be a set of data rows. A cursor is basically used to solve complex logic and works on a row by row manner. Index, on the other hand, has the main function of retrieving data from tables much quicker.

Where can we use cursor?

Use of Cursor

The major function of a cursor is to retrieve data, one row at a time, from a result set, unlike the SQL commands which operate on all the rows in the result set at one time. Cursors are used when the user needs to update records in a singleton fashion or in a row by row manner, in a database table.

What is a constraint in SQL?

SQL constraints are used to specify rules for the data in a table. Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted.

What is subquery in SQL?

A subquery is a query that is nested inside a SELECT , INSERT , UPDATE , or DELETE statement, or inside another subquery. The samples in this article use the AdventureWorks2016 database available for download at AdventureWorks sample databases. A subquery can be used anywhere an expression is allowed.

What is normalization in SQL?

Normalization is the process to eliminate data redundancy and enhance data integrity in the table. Normalization also helps to organize the data in the database. It is a multi-step process that sets the data into tabular form and removes the duplicated data from the relational tables.

What is difference between cluster and non cluster index?

A clustered index is used to define the order or to sort the table or arrange the data by alphabetical order just like a dictionary. A non-clustered index collects the data at one place and records at another place. It is faster than a non-clustered index.

Why do we need cursor in MySQL?

In MySQL, a cursor allows row-by-row processing of the result sets. A cursor is used for the result set and returned from a query. By using a cursor, you can iterate, or step through the results of a query and perform certain operations on each row.

What is trigger in MySQL?

A trigger is defined to activate when a statement inserts, updates, or deletes rows in the associated table. These row operations are trigger events. For example, rows can be inserted by INSERT or LOAD DATA statements, and an insert trigger activates for each inserted row.

What is views in MySQL?

MySQL Views

In SQL, a view is a virtual table based on the result-set of an SQL statement. A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database.

What is the cursor text?

Alternatively referred to as a caret, a cursor or text cursor is a blinking horizontal or vertical line ( ) that indicates where new text starts when you begin to type. For example, below is an empty text box, clicking in this box gives you a text cursor to indicate you can start typing.

What is cursor Brainly?

In computer user interfaces, a cursor is an indicator used to show the current position for user interaction on a computer monitor or other display device that will respond to input from a text input or pointing device. The mouse cursor is also called a pointer, owing to its resemblance in usage to a pointing stick.

What is cursor in Db2?

Db2 has a mechanism called a cursor . Using a cursor is like keeping your finger on a particular line of text on a printed page. In Db2, an application program uses a cursor to point to one or more rows in a set of rows that are retrieved from a table.