因此，我正在研究一个脚本，该脚本与Master进行写操作，并与slave进行读取操作。在我的机器上，我创建了两个连接方法，如下所示：
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var UserSchema = new Schema({
_id: Schema.Types.ObjectId,
salt: String,
provider: String,
name: String,
email: {
type: String,
required: true
},
password: {
type: String,
required: true
},
_subscriptions: [{
field: {
type: mongoose.Schema.ObjectId,
ref: 'Field',
},
status: String,
dateSubscribed: Date,
payments: [{}]
}],
role: String,
});
module.exports = mongoose.model('User', UserSchema);
现在，尽管在循环中运行var Field = require('../model/Field');
var express = require('express');
var router = express.Router();
var User = require('../model/User');
router.get('/',function(req, res, next) {
User.find({}, function(err, result) {
if (err) {
console.log(err);
res.send('something wrong');
}
res.status(200).send(result);
}).populate( '_subscriptions.field').exec(function (err, story) {
if (err) return handleError(err);
console.log('Here!!!!!');
});
});
router.get('/findById/:id',function(req, res, next) {
var id = req.params.id;
User.findById(id, function(err, doc) {
if (err) {
console.error('error, no entry found');
}
res.status(200).send(doc);
}).populate('field').exec(function (err, story) {
if (err) return handleError(err);
console.log('Here!!!!!');
});
});
router.get('/getSubscriptions/:id',function(req, res, next) {
var id = req.params.id;
User.findById(id, function(err, doc) {
if (err) {
console.error('error, no entry found');
}
var type = typeof(doc);
res.status(200).send(doc);
})
});
module.exports = router;
def get_read_connection():
connection = None
read_host = 'localhost'
try:
if sys.platform != 'darwin':
read_host = 'remote_rds_host.com'
read_c = pymysql.connect(
host=read_host,
user=user,
password=password,
db=db_name,
autocommit=False,
cursorclass=pymysql.cursors.DictCursor)
print('Read Connected')
except Exception as ex:
print('Exception in Read Connection')
print(str(ex))
finally:
return read_c
def get_connection():
connection = None
try:
connection = pymysql.connect(host=host,
user=user,
password=password,
db=db_name,
cursorclass=pymysql.cursors.DictCursor)
print('Connected')
except Exception as ex:
print(str(ex))
finally:
return connection
会获取先前的记录状态，但我遇到了一个奇怪的问题。执行以下操作的功能；
connection.commit()在SELECT中，我正在这样做：
def get_links(size=4):
total_links = []
sql = None
try:
if connection is not None:
# connection_read.ping(reconnect=True)
now = datetime.datetime.now()
# print("Current date and time using strftime:")
# print(now.strftime("%Y-%m-%d %H:%M"))
with connection.cursor() as cursor:
# sql = ' SELECT * from zillow_links_master where status = 0 LIMIT ' + str(size)
sql = " select license_id from " + TABLE_NAME + " WHERE status = 0 ORDER BY id LIMIT " + str(size)
print(sql)
cursor.execute(sql)
links = cursor.fetchall()
for link in links:
total_links.append(link['license_id'])
print(tuple(total_links))
print('======================================')
if len(total_links) > 0:
if connection is not None:
now = datetime.datetime.now()
# print("Current date and time using strftime:")
# print(now.strftime("%Y-%m-%d %H:%M"))
with connection.cursor() as cursor:
format_strings = ','.join(['%s'] * len(total_links))
# sql = " UPDATE " + TABLE_NAME + " set is_processed = 4 WHERE url IN (%s)" % format_strings,
sql = " UPDATE " + TABLE_NAME + " set status = 1 WHERE license_id IN ({})".format(
format_strings)
cursor.execute(sql, tuple(total_links))
connection.commit()
print(cursor.rowcount)
except Exception as ex:
print('Exception in get_links')
crash_date = time.strftime("%Y-%m-%d %H:%m:%S")
crash_string = "".join(traceback.format_exception(etype=type(ex), value=ex, tb=ex.__traceback__))
exception_string = '[' + crash_date + '] - ' + crash_string + '\n'
print(exception_string)
print(sql)
if 'lost' in exception_string:
print('Connection lost')
# connection_read.ping()
finally:
return total_links
如您所见，我正在使用commit，它确实在第一次生效，但是SELECT没有返回唯一记录。我遇到的问题是，__main__仅在我使用其他读/写连接时才第一次返回新记录。否则，它只会一次又一次地返回while True:
print('Block Begin')
now = datetime.datetime.now()
# print("Current date and time using strftime:")
# print(now.strftime("%Y-%m-%d %H:%M"))
p_links = get_links(LIMIT)
for p in p_links:
l_id = p
result = parse(l_id)
store_lic_info(l_id, result)
sleep(2)
connection.commit()
print('Block End')
sleep(2)
中的相同记录。
我在做什么错？我一点都不知道。在本地和远程Amazon Aurora RDS上的行为相同。