Cursor Loop
Use of cursors in WHILE and LOOP statements is called a cursor loop. Generally, OPEN, FETCH, and CLOSE statements are involved in this kind of loop. The following describes a loop that simplifies a cursor loop without the need for these operations. This kind of loop is applicable to a static cursor loop, without executing four steps about a static cursor.
Syntax
Figure 1 shows the syntax diagram of the FOR AS loop.
Precautions
The UPDATE operation for the queried table is not allowed in the loop statement.
The variable loop_name is automatically defined and is valid only in this loop. Its type is the same as that in the select_statement query result. The value of loop_name is the query result of select_statement.
The %FOUND, %NOTFOUND, and %ROWCOUNT attributes access the same internal variable in openGauss. Transactions and the anonymous block do not support multiple cursor accesses at the same time.