How to join two tables by multiple columns in SQL?
Yes: You can use Inner Join to join on multiple columns. Create table Insert values
MySQL
Column ‘user_id’ in field list is ambiguous
It means that both tables in the query have the column user_id. You need to specify which one you want to get in the SELECT statement like SELECT username, image, re.user_id
what does “/index.php?admin/admin_dashboard” in my url mean
have an already coded application in PHP/MySQL about school management. I am trying to further customize it as it is no longer serviced by the provider. I see /index.php?admin/admin_dashboard on the address bar but cannot find any file named admin_dashboard. Can anybody help about what it means? I am a novice programmer in PHP with practically no experience. actually, it … Read more
Disable ONLY_FULL_GROUP_BY
Solution 1: Remove ONLY_FULL_GROUP_BY from mysql console you can read more here Solution 2: Remove ONLY_FULL_GROUP_BY from phpmyadmin Open phpmyadmin & select localhost Click on menu Variables & scroll down for sql mode Click on edit button to change the values & remove ONLY_FULL_GROUP_BY & click on save.
Duplicating a MySQL table, indices, and data
To copy with indexes and triggers do these 2 queries: To copy just structure and data use this one: I’ve asked this before: Copy a MySQL table including indexes
Create a new database with MySQL Workbench
Launch MySQL Workbench. On the left pane of the welcome window, choose a database to connect to under “Open Connection to Start Querying”. The query window will open. On its left pane, there is a section titled “Object Browser”, which shows the list of databases. (Side note: The terms “schema” and “database” are synonymous in … Read more
SQL Query Where Field DOES NOT Contain $x
What kind of field is this? The IN operator cannot be used with a single field, but is meant to be used in subqueries or with predefined lists: If you are searching a string, go for the LIKE operator (but this will be slow): If you restrict it so that the string you are searching … Read more
ERROR 1396 (HY000): Operation CREATE USER failed for ‘jack’@’localhost’
Try doing a FLUSH PRIVILEGES;. This MySQL bug post on that error code appears to report some success in a case similar to yours after flushing privs.
PHP Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP
Solution : Rename your function name emailcomm() to __construct() Explanation: In previous versions of PHP, if PHP cannot find a __construct() function for a given class, it will search for the old-style constructor function, by the name of the class, but now old style constructors are DEPRECATED in PHP 7.0, and will be removed in a future version. You should always use __construct() in new code. Read php manual
Select from multiple tables without a join?
You could try something like this: