Opening Cursor in PL/SQL
cursor_name Name of the cursor argument_1,…,argument_n A series of arguments. The arguments specified are optional. OPEN pets; Name of the cursor
Opening and Closing Cursor Variables
After declaring a cursor variable, you can open it with the OPEN FOR statement, which does the following:- Associates the cursor variable with a query (typically, the query returns multiple rows)
The query can include placeholders for bind variables, whose values you specify in the USING clause of the OPEN FOR statement. - Allocates database resources to process the query
- Processes the query; that is:
- Identifies the result set If the query references variables, their values affect the result set.
- If the query has a FOR UPDATE clause, locks the rows of the result set
- Positions the cursor before the first row of the result set
You need not close a cursor variable before reopening it (that is, using it in another OPEN FOR statement). After you reopen a cursor variable, the query previously associated with it is lost.
When you no longer need a cursor variable, close it with the CLOSE statement, thereby allowing its resources to be reused. After closing a cursor variable, you cannot fetch records from its result set or reference its attributes.
If you try, PL/SQL raises the predefined exception INVALID_CURSOR. You can reopen a closed cursor variable.
