We generally set the primary key of a database table as “auto-increment”. The auto-increment column of your MySQL table has a maximum value based on the integer type. When you have a lot of data in your table, the auto-increment value can be exhausted by reaching its maximum value. After that, no data can be … Read more
I got the error “Trigger already exists” error while I was re-importing a MySQL database. A solution to this problem is to create DROP queries for all the Triggers of the database. SELECT Concat('DROP TRIGGER ', Trigger_Name, ';') FROM information_schema.TRIGGERS WHERE TRIGGER_SCHEMA = 'your_database_name'; This will print out the DROP statements for all the triggers. … Read more
This article provides the solution to the following MySQL error: ERROR 2006 (HY000): MySQL server has gone away We generally get this kind of error when we try to import or insert a large volume of data into the MySQL database. To solve this error, we can: – either update the MySQL’s configuration file: my.cnf … Read more
This article provides the solution to the following MySQL error: The server quit without updating PID file Open terminal Kill the MySQL process There are different ways to kill the MySQL process. You can try any one of them. Below are some of the ways listed: WAY 1 Run the following command to find the … Read more
This article shows how you can create a simple CRUD (Create, Read, Update, Delete) application in Node.js using MySQL as database. We will also be using Express Framework to build this Node.js web application. We will be using EJS as templating engine. We will be using HTTP Methods like GET, PUT, POST, DELETE to make … Read more
This article shows SQL query to get size (in MB) of all MySQL databases. It also shows the query to get the size (in MB) of all the tables present in any particular database. Get size (in MB) of all MySQL databases SELECT table_schema "Database Name", sum( data_length + index_length ) / 1024 / 1024 … Read more
Here are step-by-step commands about installing apache, php, mysql, and phpmyadmin on ubuntu. 1) Open Terminal – Press: CTRL + ALT + T 2) Install Apache – In terminal, type: sudo apt-get install apache2 – To test if Apache installation, Open browser and type: http://localhost – It should show text: It Works! 3) Install PHP … Read more
This article shows:- – How to add column to mysql database table after the table has already been created – How to delete column from mysql database table after the table has already been created – How to add foreign key to table column after the table has already been created Basically, all this can … Read more
Some definitions of foreign key:- A FOREIGN KEY in one table points to a PRIMARY KEY in another table. A foreign key is a field in a relational table that matches the primary key of another table. The foreign key can be used to cross-reference tables. A table may have multiple foreign keys, and each … Read more