mysql循环查询结果

DELIMITER //
CREATE PROCEDURE BatchUpdate()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE id INT;
    DECLARE value VARCHAR(255);
    DECLARE cur CURSOR FOR SELECT id, value FROM your_table;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO id, value;
        IF done THEN
            LEAVE read_loop;
        END IF;
        -- 在这里进行批量更新操作
        UPDATE your_table SET new_value = CONCAT(value, '_updated') WHERE id = id;
    END LOOP;

    CLOSE cur;
END //
DELIMITER ;

import mysql.connector

db = mysql.connector.connect(host="localhost", user="user", password="password", database="your_database")
cursor = db.cursor(dictionary=True)

query = "SELECT id, value FROM your_table LIMIT %s OFFSET %s"
page_size = 1000
offset = 0

while True:
    cursor.execute(query, (page_size, offset))
    rows = cursor.fetchall()
    if not rows:
        break
    for row in rows:
        # 在这里进行逐行处理
        print(row)
    offset += page_size

cursor.close()
db.close()