What is Oracle Refcursor?
A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database. In essence, a REF CURSOR is a pointer or a handle to a result set on the database. REF CURSOR s are represented through the OracleRefCursor ODP.NET class.
How do I declare a ref cursor in Oracle?
First you have to create the “weak ref cursor type” and then you have to create “a cursor variable” using that ref cursor. When using SYS_REFCURSOR, you just have to create a cursor variable and nothing else. SYS_REFCURSOR completely minimizes the first step where you create the weak ref cursor type.
How do you return a cursor in Oracle?
CREATE OR REPLACE FUNCTION get_allitems RETURN SYS_REFCURSOR AS my_cursor SYS_REFCURSOR; BEGIN OPEN my_cursor FOR SELECT * FROM allitems; RETURN my_cursor; END get_allitems; This will return the cursor.
How does cursor work in Oracle?
To execute a multi-row query, Oracle opens an unnamed work area that stores processing information. A cursor lets you name the work area, access the information, and process the rows individually. For more information, see “Querying Data with PL/SQL”.
Do I need to close Sys_refcursor?
Hence you close a ref cursor after you fetch from it. If you lose your result set — that indicates you are not done with the ref cursor. just treat a ref cursor as you would any other cursor, close it after you are finished with it.
What is the difference between ref cursor and Sys_refcursor?
There is no difference between using a type declared as REF CURSOR and using SYS_REFCURSOR , because SYS_REFCURSOR is defined in the STANDARD package as a REF CURSOR in the same way that we declared the type ref_cursor . type sys_refcursor is ref cursor; SYS_REFCURSOR was introduced in Oracle 9i.
Why do we use cursors?
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.
How do I run a cursor in SQL?
To work with cursors you must use the following SQL statements: DECLARE CURSOR. OPEN. FETCH….Cursors in SQL procedures
- 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.
How many rows can a cursor hold?
A cursor can hold more than one row, but can process only one row at a time. The set of rows the cursor holds is called the active set.
Why does my mouse pointer suddenly disappear?
If you’re using an external monitor and keyboard with a laptop, check to see that nothing is resting on the laptop’s touchpad, mouse buttons or integrated pointing device; this can cause the mouse cursor to vanish due to conflicting inputs.
How do I get my cursor back?
How to Fix Cursor Disappearing on Windows 10 Method 1: Enabling the Mouse Device. This method is used to fix the problem by enabling your mouse device. Method 2: Mouse Drivers. Sometimes, the issue is with the drivers of the mouse. Method 3: Changing Pointer Settings. Method 4: Changing Registry Settings. Method 5: Configure Pointer Size. Method 6: Toggle Hardware Acceleration.
What is Oracle SQL cursor?
The Cursor is a handle (name or a pointer) for the memory associated with a specific statement. A cursor is basically an Area alocated by Oracle for executing the Sql Statements. Oracle Uses an Implicit Cursor statement for a single row query and Explicit Cursor for a multi row query.
What is a PL SQL cursor?
A cursor is a pointer to this context area. PL/SQL controls the context area through a cursor. A cursor holds the rows (one or more) returned by a SQL statement. The set of rows the cursor holds is referred to as the active set.
