135 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			135 lines
		
	
	
		
			5.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
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								title: SQL Create Table
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								# SQL CREATE TABLE
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								## Introduction
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								This guide is an overview to the basics of the SQL `CREATE TABLE` functions. 
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								We will be using MySQL for all examples throughout these freeCodeCamp SQL guides. MySQL is a used frequently on websites for the backend database, 2) it's free, and is fun and easy to use.
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								## Covered in this Guide
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								* Creating a schema, the container for all our database objects.
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								* Create a table so we have something to alter. 
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								* Creating a table by importing a CSV file and altering that table
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								* Creating a table using the MySQL workbench tool
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								We do most of this work with SQL statements in the MySQL workbench scripting tool.  We will also see how to Create a table using the workbench interface instead of with SQL statements.
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								## High level structure of a Relational Database
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								1. Highest level; The Database; the database system installation.  In this case, it’s MySQL. Called “Local instance MySQL Router” in the screen shots above.
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								2. Next is a Schema; a container for the objects needed to managed data in a relational database system.
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								3. Objects we create (tables, indexes, stored procedures, functions) to manage the system and its data
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								## Creating a MySQL schema
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								The schema is a container for a the objects required to manage the data for a given subject or process.  We show examples as we progress in this guide.
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								We’ll create the schema for our learning and testing using the SQL command;
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								```
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								create database fCC_alterTableGuide;
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								```
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								This instances schema structure prior to running this command
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								This instances schema structure after running the SQL statement
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								## Creating a table, add test data with "insert", rename the table (alter)
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								We’ll create a Student Table.
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								The steps will be: 
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								1. make sure we don’t have the table already 
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								2. create the table 
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								3. insert the test data.
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								* Data Types: the student name is a character field limited to 90 characters
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								* The student ID is a number (integer) (range of -2147483648 to 2147483647). This will be the primary key for the table and will auto increment when a record is added.
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								* There will also be two "time-stamp" fields to play with as well
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								Create statement and display of results from execution;
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								Using a Select statement we'll see that the table is there but now records have been added.
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								Now to insert some data and see what our new table looks like with records in it (and understand create and update timestamps);
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								The first time stamp is the creation data and time and the 2nd is the update date and time.  Changing a record should update ts2 but not ts1. Let's take a look.
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								## Create a table with the MySql Workbench
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								Right click on the "Tables" under the schema you want the new file placed in. Select Create Table.
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								Complete the form as desired and click Apply
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								## Create Table as Select (CTAS)
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								A quick way to create a copy of a table, including data is to create table as select.
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								CREATE TABLE my_table as (SELECT * FROM orig_tbl);
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								## Create and populate a table by importing a CSV file
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								Right click on the "Tables" under the schema you want the new file placed in. Select Table Data Import.
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								Select the CSV file to import and click NEXT
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								Usually you create a new table from the data, select the options desired and click NEXT
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								Adjust the data types as needed and click NEXT
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								Click NEXT (on this screen and the next one that is displayed) to import the data into the table
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								You’ll see completion status, review and click FINISH
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								## Other Material
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								There lots more detail to cover this topic so install MySQL and have fun!
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								### Where to get MySQL
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								Try [this download for Windows users[(https://dev.mysql.com/downloads/windows/)
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								### MySQL documentation
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								* <a href='https://dev.mysql.com/doc/refman/5.7/en/alter-table.html' target='_blank' rel='nofollow'>manual page</a>
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								* <a href='https://dev.mysql.com/doc/refman/5.7/en/alter-table-examples.html' target='_blank' rel='nofollow'>examples from manual</a>
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								### SQL Server documentation
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								* <a href='https://docs.microsoft.com/en-us/sql/t-sql/statements/create-table-transact-sql' target='_blank' rel='nofollow'>Microsoft Docs</a>
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