How do I use two cursors in PL SQL?

Can we use two cursors in a procedure in Oracle?

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.

Can we have 2 cursors in a procedure?

Your use of cursors here is totally inappropriate. Your logic in the second cursor is also flawed since it will select any record which inludes the friend, not just the required friendship. If you wanted to fix it you could try giving the second cursor a differant name, but preferably start over.

How do I pass a value from one cursor to another cursor in Oracle PL SQL?

1 Answer. It is possible to reference another cursor within the first one: declare cursor c1 is select distinct Assigned from table_name; cursor c2(p_Assigned in varchar2) is select id, Assigned from table_name where Assigned = p_Assigned; begin for r1 in c1 loop dbms_output.

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How do I select a cursor in SQL?

Cursor in SQL Server

  1. DECLARE statements – Declare variables used in the code block.
  2. SETSELECT statements – Initialize the variables to a specific value.
  3. DECLARE CURSOR statement – Populate the cursor with values that will be evaluated. …
  4. OPEN statement – Open the cursor to begin data processing.

Can we use subquery in cursor?

You can use cursor subqueries, also know as cursor expressions, to pass sets of rows as parameters to functions.

Can we declare cursor inside begin in Oracle?

In general, yes you can, you just nest another execution block inside your current one…

What is ref cursor in Oracle with example?

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 you declare a cursor inside a for loop?

The cursor variable, opening of cursor, fetching and closing of the cursor will be done implicitly by the FOR loop. Syntax: DECLARE CURSOR IS

How do you call a cursor?

To use cursors in SQL procedures, you need to do the following:

  1. Declare a cursor that defines a result set.
  2. Open the cursor to establish the result set.
  3. Fetch the data into local variables as needed from the cursor, one row at a time.
  4. Close the cursor when done.

What is meant by cursor in Oracle?

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.

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What is the difference between cursor and ref cursor?

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 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.

Is open cursors dynamic parameter?

OPEN_CURSORS specifies the maximum number of open cursors (handles to private SQL areas) a session can have at once. You can use this parameter to prevent a session from opening an excessive number of cursors.

OPEN_CURSORS.

Property Description
Default value 50
Modifiable ALTER SYSTEM
Range of values 0 to 65535
Basic Yes