CURSOR <游标名称> IS <游标名称>%ROWTYPE; BEGIN OPEN <游标名称> LOOP FETCH <游标名称> INTO ; EXIT WHEN <游标名称>%NOTFOUND; <其它要执行的代码> END LOOP; CLOSE <游标名称>; END <存储过程名称>; / 代码例子: 复制内容到剪贴板 程序代码 TRUNCATE TABLE loop_test; DECLARE CURSOR ao_cur IS ...
which creates a portal given a prepared statement and values for any needed parameters; and an execute step that runs a portal's query. In the case of a query that returns rows (SELECT, SHOW, etc), the execute step can be told to fetch only...
Once a cursor has been opened, it can be manipulated with the statements described here. These manipulations need not occur in the same function that opened the cursor to begin with. You can return a refcursor value out of a function and let the caller operate on the cursor. 3.1. FETCH F...
DO $$ DECLARE c3 CURSOR FOR SELECT * FROM employees; rowvar employees%ROWTYPE; BEGIN OPEN c3; LOOP FETCH FROM c3 INTO rowvar; EXIT WHEN NOT FOUND; END LOOP; CLOSE c3; END$$; Example of MOVE a cursor without fetching data MOVErepositions a cursor without retrieving any data...
A FETCH statement sets FOUND true if it returns a row, false if no row is returned. A MOVE statement sets FOUND true if it successfully repositions the cursor, false otherwise. A FOR or FOREACH statement sets FOUND true if it iterates one or more times, else false. FOUND is set this...
The query might be suspended during execution. In any situation in which the system thinks that partial or incremental execution might occur, no parallel plan is generated. For example, a cursor created using DECLARE CURSOR will never use a parallel plan. Similarly, a PL/pgSQL loop of the fo...
使用cursor.execute 和SQL SELECT 语句来读取数据。 cursor.fetchall() 用于接受查询并返回结果集以进行迭代。 Python 复制 # Fetch all rows from table cursor.execute("SELECT * FROM pharmacy;") rows = cursor.fetchall() # Print all rows for row in rows: print("Data row = (%s, %s)" %(str...
BEGIN; SELECT * FROM myfunc('a', 'b'); FETCH ALL FROM a; FETCH ALL FROM b; COMMIT; for游标循环 [ <> ] FOR recordvar IN bound_cursorvar [ ( [ argument_name := ] argument_value [, ...] ) ] LOOP statements END LOOP [ label ]; 异常消息处理 抛出异常 RAISE [ level ] ...
The query tree created by the transformation process is structurally similar to the raw parse tree in most places, but it has many differences in detail. For example, aFuncCallnode in the parse tree represents something that looks syntactically like a function call. This might be transformed to...
*/DBMS_SQL.BIND_ARRAY(c,':dept_array', dept_no_array,1,4);/* Bind only elements 1 through 4 to the cursor Happens 4 times */dummy :=DBMS_SQL.EXECUTE(c);/* Execute the Query, and return number of rows deleted! */DBMS_SQL.CLOSE_CURSOR(c); ...