我们有MySQL5.7主从复制，在从服务器端，我们的应用程序监控工具(Tideways和PHP7.0)不时报告MySQLhasgoneaway.检查MYSQL端:showglobalstatuslike'%Connection%';+-----------------------------------+----------+|Variable_name|Value|+-----------------------------------+----------+|Connection_errors_accept|0||Connection_errors_internal|0||Conn
我们有MySQL5.7主从复制，在从服务器端，我们的应用程序监控工具(Tideways和PHP7.0)不时报告MySQLhasgoneaway.检查MYSQL端:showglobalstatuslike'%Connection%';+-----------------------------------+----------+|Variable_name|Value|+-----------------------------------+----------+|Connection_errors_accept|0||Connection_errors_internal|0||Conn
我有以下SQL查询。SELECTSUM(final_insurance_total)astotalFROM`leads`GROUPBYleads.status我在lead表中有一行数据，final_insurance_total的值为458796。final_insurance_total的数据类型是float。出于某种原因，MySQL将单行求和为“458796.375”。如果我将查询更改为SELECT(final_insurance_total)astotalFROM`leads`GROUPBYleads.status返回正确的值。这到底是怎么回事？ 最佳
我有以下SQL查询。SELECTSUM(final_insurance_total)astotalFROM`leads`GROUPBYleads.status我在lead表中有一行数据，final_insurance_total的值为458796。final_insurance_total的数据类型是float。出于某种原因，MySQL将单行求和为“458796.375”。如果我将查询更改为SELECT(final_insurance_total)astotalFROM`leads`GROUPBYleads.status返回正确的值。这到底是怎么回事？ 最佳
你能给我解释一下如何为数据库配置设置端口号吗:classMY_ModelextendsCI_Model{protectedstatic$db2_loaded=false;protectedstatic$db2=false;function__construct(){parent::__construct();if(($this->session->userdata('login_user')!=false)&&!self::$db2_loaded){self::$db2_loaded=true;$config['hostname']="localhost";$config['usern
你能给我解释一下如何为数据库配置设置端口号吗:classMY_ModelextendsCI_Model{protectedstatic$db2_loaded=false;protectedstatic$db2=false;function__construct(){parent::__construct();if(($this->session->userdata('login_user')!=false)&&!self::$db2_loaded){self::$db2_loaded=true;$config['hostname']="localhost";$config['usern
我在MySQL5.1.38中有两个表。products+----+------------+-------+------------+|id|name|price|department|+----+------------+-------+------------+|1|FireTruck|15.00|Toys||2|Bike|75.00|Toys||3|T-Shirt|18.00|Clothes||4|Skirt|18.00|Clothes||5|Pants|22.00|Clothes|+----+------------+-------+------------+ratings+-
我在MySQL5.1.38中有两个表。products+----+------------+-------+------------+|id|name|price|department|+----+------------+-------+------------+|1|FireTruck|15.00|Toys||2|Bike|75.00|Toys||3|T-Shirt|18.00|Clothes||4|Skirt|18.00|Clothes||5|Pants|22.00|Clothes|+----+------------+-------+------------+ratings+-
为什么我得到ERROR1222(21000):TheusedSELECTstatementshaveadifferentnumberofcolumnsfromthefollowing?SELECT*FROMfriendsLEFTJOINusersASu1ONusers.uid=friends.fid1LEFTJOINusersASu2ONusers.uid=friends.fid2WHERE(friends.fid1=1)AND(friends.fid2>1)UNIONSELECTfid2FROMfriendsWHERE(friends.fid2=1)AND(friends.fid1用
为什么我得到ERROR1222(21000):TheusedSELECTstatementshaveadifferentnumberofcolumnsfromthefollowing?SELECT*FROMfriendsLEFTJOINusersASu1ONusers.uid=friends.fid1LEFTJOINusersASu2ONusers.uid=friends.fid2WHERE(friends.fid1=1)AND(friends.fid2>1)UNIONSELECTfid2FROMfriendsWHERE(friends.fid2=1)AND(friends.fid1用
