RQ4

import sys
import logging
import rds_config
import pymysql
#rds settings
rds_host  = rds_config.db_endpoint
name = rds_config.db_username
password = rds_config.db_password
db_name = rds_config.db_name
port = 3306

logger = logging.getLogger()
logger.setLevel(logging.INFO)

try:
    logger.info("muestra esto")
    conn = pymysql.connect(rds_host, user=name, passwd=password, db=db_name, connect_timeout=120)
except Exception as inst:
    logger.error("ERROR : ")
    logger.error(inst)
    sys.exit()

logger.info("SUCCESS: Connection to RDS mysql instance succeeded")

def handler(event, context):
    item_count = 0
    sql = """
CREATE INDEX AnswersIdx ON Answers(Id);
CREATE INDEX PostsIdx ON Posts(Id);

CREATE INDEX AuthorAnswersIdx ON Answers(OwnerUserId);
CREATE INDEX AuthorPostsIdx ON Posts(OwnerUserId);

SELECT
    CASE WHEN (ua1 > up1) THEN up1 ELSE ua1 END AS Helper,
    CASE WHEN (ua1 > up1) THEN ua1 ELSE up1 END AS Helpee
FROM (
    SELECT a1.OwnerUserId AS ua1, p1.OwnerUserId AS up1
    FROM Answers AS a1
    INNER JOIN Posts AS p1
        ON p1.PostTypeId = 1
        AND a1.ParentId = p1.Id
        AND p1.OwnerUserId != a1.OwnerUserId
    GROUP BY ua1, up1
    ) AS r1
JOIN (
    SELECT a2.OwnerUserId AS ua2, p2.OwnerUserId AS up2
    FROM Answers AS a2
    INNER JOIN Posts AS p2
        ON p2.PostTypeId = 1
        AND a2.ParentId = p2.Id
        AND p2.OwnerUserId != a2.OwnerUserId
    GROUP BY ua2, up2
    ) AS r2
    ON r1.up1 = r2.ua2 AND r1.ua1 = r2.up2
GROUP BY Helper, Helpee;
        """
    item_count = 0
    with conn.cursor() as cur:
        cur.execute(sql)
        conn.commit()
        for row in cur:
            item_count += 1
            logger.info(row)
    return "Filas generadas: %d" %(item_count)