Column-level restrictions apply to a single column, while table-level restrictions apply to the entire table. This ensures the accuracy and reliability of the database data.Ĭonstraints can be at column or table level. They are used to limit the type of data that can be included in a table. It doesn’t mean ‘zero’ value but just the lack of a value.Ĭonstraints are the rules that apply to the data columns in a table. ‘Null’ value: A ‘null’ value in a table is a value that appears empty. For example, a column in the ‘Customer’ table is NAME, which represents the names of all the customers. Row: A row (records or tuple) in a table represents a single, implicitly structured data.Ĭolumn: A column (or field) in a table is a vertical entity that contains all the information associated with a specific field. It is the most common and simplest form of storing data in a RDBMS.Īn example of a ‘Customer’ table is given in Figure 3. This table is a collection of related data items, and consists of rows and columns. Table: Data is stored in database objects called tables in RDBMS. To create a database, click on Database > Add Database (Ctrl + O) > New_Database A phone book uses a database to store peoples’ names, phone numbers, contact details and addresses. As an example, an electrical service provider uses a database to manage billing, customer issues and their addresses. A picture, image, file, etc, can also be considered data.Īn SQL Server database consists of a collection of tables that store a specific set of structured data. For example, your name, address, salary, date of birth, etc, is some of the data related to you. For example, another script language could be added along with it.ĭata can be facts related to any object. Plugins: SQLite Studio supports plugins of different categories. Just download the package, unzip and run it. Portable distribution: No installation is required. Multi-platform: Works on three main platforms: Windows, MacOS X, Linux. Hassle-free multiple databases: SQL statements that refer to multiple databases can be executed in a single query, thanks to the transparent database connection mechanism built into the SQL editor of SQLite Studio.ĭrag and drop between databases: It is possible to drag objects (tables, indexes,…) between databases to copy or move them, with or without data. We’ll start with the basics - what is a database and how to create one what are tables, rows, columns, constraints, and how to create a table and execute it with some keyboard shortcuts for quick results.įree and open source: It is free for everyone, for any purpose (including commercial).Īdvanced SQL Code Editor: The SQL Editor window highlights and offers hints on SQL syntax, providing a print code formatter, and flags syntax errors.
This article provides the basics needed to effectively use SQLite in any database environment. SQLite Studio is an open source, compact, standard and easy to install cross-platform database management system. However, it is not fully portable between some different database systems without adjustments.
SQL became a standard of the American National Standards Institute (ANSI) in 1986 and of the International Organization for Standardization (ISO) in 1987. Tables are linked together by common keys or fields in a relational database system, so that even if the data you want is in multiple tables, it can be easily joined these to get an integrated data set using a query. Relational databases allow data to be broken down into smaller, logical and manageable units for easier maintenance and better performance. This article is designed to help the reader understand the most common database management language, SQL.Ī relational database is a database divided into logical units called tables, where the tables are linked together in the database. Knowing how to code and manage related databases and database-driven applications is an important skill for any technology career.
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