mysql

问题 I am doing unit tests on requests generators, and I get in trouble with LENGTH function. I have 2 requests that follows each other : SHOW VARIABLES LIKE '%character%' Returns the following result : array(8) { [0] => array(2) { 'Variable_name' => string(20) "character_set_client" 'Value' => string(4) "utf8" } [1] => array(2) { 'Variable_name' => string(24) "character_set_connection" 'Value' => string(4) "utf8" } [2] => array(2) { 'Variable_name' => string(22) "character_set_database" 'Value' =

问题 I wanted to know if there is any way where i can calculate time difference between two rows. I want to calculate time difference for name -> test etc. The name can be in any order. I want to know if test has two times at row 1 and 3 and then at row 7 and 11, can i calculate time difference between these rows? i.e for row 1 and 3, and other for row 7 and 11. below image with my database 回答1: try using TIMEDIFF() and subquery SELECT TIMEDIFF((SELECT `entered_at` FROM `demo_test3` WHERE `id`='1'

问题 I wanted to know if there is any way where i can calculate time difference between two rows. I want to calculate time difference for name -> test etc. The name can be in any order. I want to know if test has two times at row 1 and 3 and then at row 7 and 11, can i calculate time difference between these rows? i.e for row 1 and 3, and other for row 7 and 11. below image with my database 回答1: try using TIMEDIFF() and subquery SELECT TIMEDIFF((SELECT `entered_at` FROM `demo_test3` WHERE `id`='1'

问题 I have a dataset like: id | country | date | rank | sport -------------------------------------------- 1 | US | 2000-01-30 | 1 | tennis 2 | BE | 2000-01-30 | 2 | tennis 3 | UK | 2000-01-30 | 3 | tennis 4 | UK | 2000-01-30 | 1 | golf 5 | US | 2000-01-30 | 2 | golf 6 | FR | 2000-01-30 | 3 | golf 7 | UK | 2000-01-31 | 1 | tennis 8 | US | 2000-01-31 | 2 | tennis 9 | FR | 2000-01-31 | 3 | tennis 10 | UK | 2000-01-31 | 1 | golf 11 | US | 2000-01-31 | 2 | golf 12 | FR | 2000-01-31 | 3 | golf I'd

问题 So far I have been able to get data from MYSQL and display it as a checklist using PHP and HTML. Now I would like to limit the number of checkboxes that can be selected at a time. Javascript doesn't seem to be working with my PHP code. EDIT: I've included my JScript below which is currently not workng. This JScript only works when I use it with manually created html checklists but not the one I have made below using MYSQL data. How can I fix my Javascript part so this works? Here is my code:

问题 when i query the database using php my admin the following sql works update invoice set paid = 1, date_recieved = 0000-00-00, check_number = 00000 where invoice_number IN (110038,110035,110033) i have a text box where a user enters numbers separated by a comma. this is submitted via post to the $invoice variable. when i run the following only the first row is affected. the code commented out is things that i tried but didn't work if(isset($_POST["paymentbtn"])){ $invoice = $_POST["invoice"];

问题 According to the MySQL documentation: As a general rule, you should never assign a value to a user variable and read the value within the same statement. You might get the results you expect, but this is not guaranteed. http://dev.mysql.com/doc/refman/5.6/en/user-variables.html However, in the book High Perfomance MySQL there are a couple of examples of using this tactic to improve query performance anyway. Is the following an anti-pattern and if so is there a better way to write the query

问题 I am trying to install MySQL Server, mysql-installer-community-8.0.19.0.msi, on Windows 10. I download the latest version from MySQl::MySQL Downloads These are the screenshots: I selected Full : I think something went wrong here: 回答1: this usually happens because you did not install the requirements manually in the previous steps. I recommend that you uninstall and install back again. After that, you will click on these items to try to resolve them manually. It performs the installation of

问题 i have a table in my db called events here is some info about the table 106,528 ROWS - InnoDB - utf8mb4_unicode_ci - 35.1 MiB in this table i store sport match events today i've noticed something weird , when i run a select query i get something different time to time this is the query , basically looking for the matches without the result select * from `events` where `stat_forms` > '0' and ((`result_added` = '0' and `archived` = '0' and `start_time` < '1530901263') or `result_error_flag` !=

问题 I am trying to implement the timeline google chart https://developers.google.com/chart/interactive/docs/gallery/timeline but using date format is creating some errors in generating the chart . All dates are set default to dec 31 1969 . I know that I am passing a wrong format of date. How can I fix this. tried implementing in two ways : $table['cols'] = array( array('id' => 'Role', 'type' => 'string'), array('id' => 'Name', 'type' => 'string'), array('id' => 'Start', 'type' => 'date'), array(