mysql怎么循环查询结果

DELIMITER //

CREATE PROCEDURE LoopThroughResults()
BEGIN
  DECLARE done INT DEFAULT FALSE;
  DECLARE v_id INT;
  DECLARE v_name VARCHAR(255);
  DECLARE cur CURSOR FOR SELECT id, name FROM your_table;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

  OPEN cur;

  read_loop: LOOP
    FETCH cur INTO v_id, v_name;
    IF done THEN
      LEAVE read_loop;
    END IF;
    -- 在这里处理每一行的数据
    SELECT v_id, v_name;
  END LOOP;

  CLOSE cur;
END //

DELIMITER ;

import mysql.connector

mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword",
  database="yourdatabase"
)

mycursor = mydb.cursor()

mycursor.execute("SELECT id, name FROM your_table")

for row in mycursor:
  print(row)

DECLARE cur CURSOR FOR SELECT id, name FROM your_table;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

-- 分批次处理数据
DECLARE batch_size INT DEFAULT 1000;
DECLARE offset INT DEFAULT 0;

read_loop: LOOP
  FETCH cur INTO v_id, v_name FROM your_table LIMIT batch_size OFFSET offset;
  IF done THEN
    LEAVE read_loop;
  END IF;
  -- 处理每一批的数据
  SET offset = offset + batch_size;
END LOOP;