In MySQL, a cursor is a database object used to iterate through a set of rows returned by a query, allowing for row-by-row processing. This is particularly useful in stored procedures, where you might need to process each row individually[1][2][3][5].
Properties of MySQL Cursors
MySQL cursors have several key properties:
Asensitive: The server may or may not make a copy of its result table. This means the cursor might not reflect changes made to the tables by other transactions after the cursor was created[2].
Read-only: Cursors in MySQL are non-updatable, which means you cannot use a cursor to modify data in the underlying tables[2].
Nonscrollable: MySQL cursors can only move forward through the result set and cannot skip rows or move backwards. Once a row has been fetched, it cannot be fetched again without re-opening the cursor[2][3].
Lifecycle: The typical lifecycle of a cursor in MySQL involves several steps:
Declaration: You declare a cursor with a specific SQL query.
Opening: Before fetching rows, the cursor must be opened.
Fetching: Rows are retrieved one at a time from the cursor.
Closing: After all rows are processed, the cursor should be closed to free up resources[1][2][3][5].
Scope: Cursors are local to the stored procedure, function, or trigger in which they are declared. They cease to exist once the stored program ends unless...
