eduguru UNIQUE Constraint The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. A PRIMARY KEY constraint automatically has a UNIQUE constraint. However, you can have many UNIQUE constraints per table, but only one PRIMARY KEY constraint per table. This constraint ensures that all values inserted into the column … Read more
NOT NULL Constraint By default, a column can hold NULL values. The “NOT NULL constraint” enforces a column to NOT accept NULL values. This enforces a field to always contain a value, which means that you cannot insert a new record, or update a record without adding a value to this field. This constraint specifies that … Read more
MySQL Constraints SQL constraints are used to specify rules for data in a table. The constraint in MySQL is used to specify the rule that allows or restricts what values or data will be stored in the table. They provide a suitable method to ensure data accuracy and integrity inside the table. It also helps … Read more
MySQL CREATE TABLE Statement The MySQL CREATE TABLE Statement The CREATE TABLE statement is used to create a new table in a database. Syntax CREATE TABLE table_name ( column1 datatype, column2 datatype, column3 datatype, …. ); The column parameters specify the names of the columns of the table. The datatype parameter specifies the type of data the … Read more
MySQL AUTO INCREMENT Field What is an AUTO INCREMENT Field? Auto-increment allows a unique number to be generated automatically when a new record is inserted into a table. Often this is the primary key field that we would like to be created automatically every time a new record is inserted. MySQL AUTO_INCREMENT Keyword MySQL uses … Read more
Install MariaDB 10.6 on CentOS 7 MariaDB is a commonly used OpenSource database mainly known for being robust and scalable with new storage engines. MariaDB is a development of MySQL which puts focus on stability and performance and makes it free to users. It is the default database in most Linux distributions. With a variety … Read more
LibreOffice Calc – Open-Source Spreadsheet Software for Linux The majority of Linux users will mention LibreOffice Calc as spreadsheet software. This open-source application forms part of the LibreOffice suite that offers a set of editors and productivity tools. LibreOffice is a fork of the OpenOffice.org project and it is managed and developed by The Document Foundation with the support of a big … Read more
How to Hack WiFi Password Wireless networks are accessible to anyone within the router’s transmission radius. This makes them vulnerable to attacks. Hotspots are available in public places such as airports, restaurants, parks, etc. Here, we will introduce you to common techniques used to exploit weaknesses in wireless network security implementations. We will also look at some … Read more
What is ARP Poisoning ARP is the acronym for Address Resolution Protocol. It is used to convert an IP address to physical addresses [MAC address] on a switch. The host sends an ARP broadcast on the network, and the recipient computer responds with its physical address [MAC Address]. The resolved IP/MAC address is then used … Read more
What is IP Address and MAC Address IP Address IP Address is the acronym for Internet Protocol address. An internet protocol address is used to uniquely identify a computer or device such as printers, storage disks on a computer network. There are currently two versions of IP addresses. IPv4 uses 32-bit numbers. Due to the … Read more