問題文
A block has to walk through the rows of a query one row at a time and the developer declares an explicit cursor for it. Which description of the four operations that an explicit cursor needs is correct?
選択肢
- The declaration names the cursor and states its query, the open operation runs that query and identifies the result set, each fetch moves one row into the target variables, and the close operation releases the result set at the end.
- The declaration states the query and the target variables together, the open operation locks the rows of the result set, each fetch releases one of those locks, and the close operation ends the transaction.
- The declaration runs the query at once, the open operation moves the first row into the target variables, each fetch counts the rows of the result set, and the close operation commits the changes that the block made.
- The declaration names the cursor and states its query, the open operation reserves the target variables, each fetch reopens the result set, and the close operation deletes the rows that were read.