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.
What is ref cursor?
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.
Is ref cursor can be used for dynamic queries?
Answer: Here is an example script that performs dynamic SQL and returns the data as a ref cursor. …
What is an implicit cursor?
An implicit cursor has attributes that return information about the most recently run SELECT or DML statement that is not associated with a named cursor. Note: You can use cursor attributes only in procedural statements, not in SQL statements.
What is cursor types of cursor and diff b W cursors?
Implicit cursors are automatically created when select statements are executed. Explicit cursors needs to be defined explicitly by the user by providing a name. They are capable of fetching a single row at a time. Explicit cursors can fetch multiple rows.
What is strong ref cursor in Oracle?
A ref cursor which has fixed return type is called a Strong Ref Cursor in Oracle Database. Because of fixed return type, strong ref cursors can only be used selectively. For instance with those SELECT statements that return the result whose datatype matches with the one that you have fixed during cursor’s declaration.
What is a REF CURSOR data type?
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.
What is SYS_REFCURSOR type in Oracle?
Using Ref Cursors To Return Recordsets Since Oracle 7.3 the REF CURSOR type has been available to allow recordsets to be returned from stored procedures and functions. Oracle 9i introduced the predefined SYS_REFCURSOR type, meaning we no longer have to define our own REF CURSOR types.
How do you return a cursor from a stored procedure?
Oracle REF CURSOR With the REF_CURSOR you can return a recordset/cursor from a stored procedure. There are 2 basic types: Strong ref cursor and weak ref cursor For the strong ref cursor the returning columns with datatype and length need to be known at compile time.
Is a REF CURSOR backward scrollable?
A REF CURSOR is not backward scrollable. The data represented by the REF CURSOR is accessed in a forward-only, serial manner. You cannot position a record pointer inside the REF CURSOR to point to random records in the result set. A REF CURSOR is a PL/SQL data type. You create and return a REF CURSOR inside a PL/SQL code block.
