- What is cursor explain with example?
- How do I run a cursor in SQL?
- Which three of the following are implicit cursor attributes?
- What occurs when a cursor is opened?
- How do you check if the cursor is empty in Oracle?
- What is Refcursor?
- What does a commit statement do to a cursor?
- What is SQL Rowcount?
- How many rows can a cursor hold?
- How do I run a cursor?
- What is difference between cursor and ref cursor?
- What is SQL cursor example?
- What is a cursor on iPhone?
- What are the cursor attributes?
- Which of the following cursor attribute is used to check the no of rows retrieved?
- Is open cursor in Oracle?
- How do I pass one cursor to another cursor?
- Is ref cursor return Oracle?
What is cursor explain with example?
Oracle creates a memory area, known as the context area, for processing an SQL statement, which contains all the information needed for processing the statement; for example, the number of rows processed, etc.
A cursor is a pointer to this context area.
A cursor holds the rows (one or more) returned by a SQL statement..
How do I run a cursor in SQL?
To use cursors in SQL procedures, you need to do the following:Declare a cursor that defines a result set.Open the cursor to establish the result set.Fetch the data into local variables as needed from the cursor, one row at a time.Close the cursor when done.
Which three of the following are implicit cursor attributes?
Which three of the following are implicit cursor attributes?%found.%too_many_rows.%notfound.%rowcount.%rowtype.
What occurs when a cursor is opened?
Opening a Cursor When a cursor is opened, the following things happen: The values of the bind variables are examined. Based on the values of the bind variables, the active set (the query result) is determined. The active set pointer is set to the first row.
How do you check if the cursor is empty in Oracle?
The “if ( l_cursor%notfound )” is what you use to test for no more data with a cursor of any type.
What is Refcursor?
A ref cursor is a variable, defined as a cursor type, which will point to, or reference a cursor result. The advantage that a ref cursor has over a plain cursor is that is can be passed as a variable to a procedure or a function. The REF CURSOR can be assigned to other REF CURSOR variables.
What does a commit statement do to a cursor?
If you commit while a FOR UPDATE cursor is open, a subsequent fetch on that cursor raises an exception. The cursor remains open, so you should still close it. For more information, see “Using FOR UPDATE”. When a distributed transaction fails, the text specified by COMMENT helps you diagnose the problem.
What is SQL Rowcount?
%ROWCOUNT yields the number of rows affected by an INSERT , UPDATE , or DELETE statement, or returned by a SELECT INTO statement. … The value of the SQL%ROWCOUNT attribute refers to the most recently executed SQL statement from PL/SQL.
How many rows can a cursor hold?
A cursor can be viewed as a pointer to one row in a set of rows. The cursor can only reference one row at a time, but can move to other rows of the result set as needed.
How do I run a cursor?
There are four steps in using an Explicit Cursor.DECLARE the cursor in the Declaration section.OPEN the cursor in the Execution Section.FETCH the data from the cursor into PL/SQL variables or records in the Execution Section.CLOSE the cursor in the Execution Section before you end the PL/SQL Block.
What is difference between cursor and ref cursor?
2 Answers. A cursor is really any SQL statement that runs DML (select, insert, update, delete) on your database. A ref cursor is a pointer to a result set. This is normally used to open a query on the database server, then leave it up to the client to fetch the result it needs.
What is SQL cursor example?
SQL Server cursor example products table: DECLARE @product_name VARCHAR(MAX), @list_price DECIMAL; DECLARE cursor_product CURSOR FOR SELECT product_name, list_price FROM production.
What is a cursor on iPhone?
With iPhone 6S, Apple introduced a feature which let the users long press anywhere on the keyboard to turn the phone into a trackpad that you could use as a cursor to select or highlight text – something you could do only on a laptop previously.
What are the cursor attributes?
Every explicit cursor and cursor variable has four attributes: %FOUND , %ISOPEN %NOTFOUND , and %ROWCOUNT . When appended to the cursor or cursor variable, these attributes return useful information about the execution of a data manipulation statement.
Which of the following cursor attribute is used to check the no of rows retrieved?
The %FOUND attribute is used to test whether or not a row is retrieved from the result set of the specified cursor after a FETCH on the cursor.
Is open cursor in Oracle?
If a cursor is open, cursor_name%ISOPEN returns TRUE ; otherwise, it returns FALSE . A cursor attribute that can be appended to the name of a cursor or cursor variable. Before the first fetch from an open cursor, cursor_name%NOTFOUND returns NULL .
How do I pass one cursor to another cursor?
The trick to declaring a cursor within a cursor is that you need to continue to open and close the second cursor each time a new record is retrieved from the first cursor. That way, the second cursor will use the new variable values from the first cursor.
Is ref cursor return Oracle?
Using REF CURSOR s is one of the most powerful, flexible, and scalable ways to return query results from an Oracle Database to a client application. A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database.