Database
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Designing Database : Database RelationshipsDatabase 2022. 1. 1. 17:22
관계형 데이터베이스에서 Relationship의 3가지 타입을 정리하였습니다. What are relationships? A database relationship establishes the way in which connected tables are dependent on one another. What are the different types of database relationships? There are three types: one-to-one, one-to-many and many-to-many. : The lines between tables connect foreign keys and primary keys. < One-to-One Relationship ..
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Designing Database : Database KeysDatabase 2021. 12. 31. 14:57
Database에서 데이터의 효율적인 정의와, 각 테이블간의 관계 설정에 사용되는 Key 키워드 사용에 대해 정리하였습니다. Will learn how to designate certain columns of a database table as keys. What are keys? A database key is a column or group of columns in a table that uniquely identifies a row in a table. Keys enable a database designer to place constraints on the data in a table. We want to enforce d..
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Designing Database : Database SchemaDatabase 2021. 12. 30. 01:55
데이터베이스를 만들기 전에, 어떻게 개요를 잡을지에 대한 방법을 정리하였습니다. Like an architectural blueprint, a database schema is documentation that helps its audience such as a database designer, administrator and other users interact with a database. It gives an overview of the purpose of the database along with the data that makes up the database, how the data is organized into tables, how the tables are i..
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Introduction to Database DesignDatabase 2021. 12. 28. 18:41
Database를 만들기 전에, 어떤 식으로 구성하면 좋을지에 대한 이해를 돕기 위해 이와 관련한 기사들을 정리해 놓았습니다. Article : Relational Database Schema Design Overview Relational Database Schema Design Overview It is about time I started reviewing my SQL and database knowledge. I started off by reviewing SQL queries as simple as selecting rows from… medium.com Article : 10 Best Database Design Practices 10 Best Database Design Practices D..
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PostgreSQL DatabaseDatabase 2021. 12. 28. 12:53
PostgreSQL을 이해 및 활용하기 위해 기본적으로 필요한 배경지식들을 정리하였습니다. Databsae - Wikipedia Database - Wikipedia From Wikipedia, the free encyclopedia Jump to navigation Jump to search Organized collection of data This article is about the computing concept. For instances of the general concept, see Lists of databases. An SQL select statement and its result In comput en.wikipedia.org Ar..
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Multiple TablesDatabase 2021. 12. 24. 01:57
SQL에서 여러 Table을 다루는 방법을 정리하였습니다. In order to efficiently store data, we often spread related information across multiple tables. Example : imagine that we’re running a magazine company where users can have different types of subscriptions to different products. order_id customer_id customer_name customer_address..
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Aggregate FunctionDatabase 2021. 12. 23. 14:50
SQL에서 계산에 이용되는 함수 사용방법에 대해 정리하였습니다. We are going to learn how to perform calculations using SQL. Calculations performed on multiple rows of a table are called aggregates. To calculate how many rows are in a table SELECT COUNT(columnName) FROM table_name; COUNT( ) is a function that takes the name of a column as an argument and counts the number of non-empty ..
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QueriesDatabase 2021. 12. 23. 01:12
SQL에서 Query문 작성하는 방법에 대해 정리하였습니다. One of the core purposes of the SQL language is to retrieve information stored in a database. This is commonly referred to as querying. Queries allow us to communicate with the database by asking questions and returning a result set with data relevant to the question. SELECT is used every time you want to query data from a database an..