There is a request to the database (an error occurs on it, the rest are processed normally. The request itself is working (checked in Workbench))

SELECT `contract`.`id` AS `#Number#`, `contract`.`date_create` AS `#Date#`, `contract`.`date_off` AS `#VozDate#`, `contract`.`days` AS `#Days#`, `contract`.`days_cred` AS `#DaysCred#`, `contract`.`summ_ocen` AS `#SummOcen#`, `contract`.`summ_ocen` AS `#SummOcenRub#`, `contract`.`summ_cred` AS `#SummCred#`, `contract`.`summ_cred` AS `#SummCredRub#`, `contract`.`proc_polz` AS `#ProcPolz#`, max(if(`object_class_method_value`.`object_class_method_id`=1,value,null)) AS `#AutoName#`, max(if(`object_class_method_value`.`object_class_method_id`=2,value,null)) AS `#AutoYear#`, max(if(`object_class_method_value`.`object_class_method_id`=4,value,null)) AS `#AutoGosNum#`, max(if(`object_class_method_value`.`object_class_method_id`=5,value,null)) AS `#AutoVIN#`, max(if(`object_class_method_value`.`object_class_method_id`=6,value,null)) AS `#AutoKuzNum#`, max(if(`object_class_method_value`.`object_class_method_id`=7,value,null)) AS `#AutoDvigNum#`, max(if(`object_class_method_value`.`object_class_method_id`=8,value,null)) AS `#AutoDvig#`, max(if(`object_class_method_value`.`object_class_method_id`=11,value,null)) AS `#AutoNumPTS#`, max(if(`object_class_method_value`.`object_class_method_id`=12,value,null)) AS `#AutoVydanPTS#`, max(if(`object_class_method_value`.`object_class_method_id`=13,value,null)) AS `#AutoNumSR#`, max(if(`object_class_method_value`.`object_class_method_id`=14,value,null)) AS `#AutoVydanSR#`, `clients`.`id`, `clients`.`fio` AS `#CliName#`, `clients`.`telephone` AS `#CliPhone#`, `clients`.`document_number` AS `#CliPasportNum#`, `clients`.`document_given` AS `#CliPasportVyd#`, `clients`.`document_given_date` AS `#CliPasportDate#`, `clients`.`registration` AS `#CliAddressProp#`, `clients`.`birth_date` AS `#CliBDate#`, `clients`.`address_living` AS `#CliAddress#`, CONCAT(`users`.`lastname`, ' ', `users`.`name`, ' ', `users`.`surname`) AS `#SotrFull#`, `users`.`authorization` AS `#SotrDover#` FROM `contract`, `object_class_method_value`, `clients`, `users` WHERE `contract`.`id` = 2396 AND `object_class_method_value`.`object_id` = `contract`.`object_id` AND `users`.`id` = `contract`.`user_id` GROUP BY `object_class_method_value`.`object_id`;

There is such a function in the program (clipping):

 //Здесь открывается соединение MySqlCommand command = new MySqlCommand(sqlQuery, Connect); MySqlDataReader reader = command.ExecuteReader(); \\Вот здесь рушится while (reader.Read()) { //Обрабатывается и закрывается

With an error

 Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
  • What are you doing with this max(if( object_class_method_value . Object_class_method_id =1,value,null)) trying to achieve? - Anton Shchyrov
  • @Anton something like this sql.ru/forum/1209158/… - Anton Kartushin

1 answer 1

The request is creepy. For some reason grouping is used. Records from the clients table stupidly multiply. I think that the multiplication of records is the main problem

Here you have the correct request

 SELECT ct.`id` AS `#Number#`, ct.`date_create` AS `#Date#`, ct.`date_off` AS `#VozDate#`, ct.`days` AS `#Days#`, ct.`days_cred` AS `#DaysCred#`, ct.`summ_ocen` AS `#SummOcen#`, ct.`summ_ocen` AS `#SummOcenRub#`, ct.`summ_cred` AS `#SummCred#`, ct.`summ_cred` AS `#SummCredRub#`, ct.`proc_polz` AS `#ProcPolz#`, name.value,null AS `#AutoName#`, year.value AS `#AutoYear#`, ........... VydanSR.value AS `#AutoVydanSR#`, cl.`id`, cl.`fio` AS `#CliName#`, cl.`telephone` AS `#CliPhone#`, cl.`document_number` AS `#CliPasportNum#`, cl.`document_given` AS `#CliPasportVyd#`, cl.`document_given_date` AS `#CliPasportDate#`, cl.`registration` AS `#CliAddressProp#`, cl.`birth_date` AS `#CliBDate#`, cl.`address_living` AS `#CliAddress#`, CONCAT(usr.`lastname`, ' ', usr.`name`, ' ', usr.`surname`) AS `#SotrFull#`, usr.`authorization` AS `#SotrDover#` FROM `contract` ct LEFT JOIN `object_class_method_value` name ON ( name.`object_id` = ct.`object_id` AND name.`object_class_method_id` = 1 ) LEFT JOIN `object_class_method_value` year ON ( year.`object_id` = ct.`object_id` AND year.`object_class_method_id` = 2 ) ...... LEFT JOIN `object_class_method_value` VydanSR ON ( VydanSR.`object_id` = ct.`object_id` AND VydanSR.`object_class_method_id` = 14 ) LEFT JOIN `clients` cl ON ( ????? ) LEFT JOIN `users` usr ON ( usr.`id` = ct.`user_id` ) WHERE ct.`id` = 2396

Instead of ????? Substitute the condition by which records are selected from the clients table and create an index on the object_class_method_value.object_class_method_id field.

Well, I hope that all the xxx_id fields you have indexed