97a852858f
Change "There lots more detail to cover this topic" to "There is a lot more detail to cover on this topic"
135 lines
5.4 KiB
Markdown
135 lines
5.4 KiB
Markdown
---
|
||
title: SQL Create Table
|
||
---
|
||
# SQL CREATE TABLE
|
||
|
||
## Introduction
|
||
|
||
This guide is an overview to the basics of the SQL `CREATE TABLE` functions.
|
||
|
||
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.
|
||
|
||
## Covered in this Guide
|
||
|
||
* Creating a schema, the container for all our database objects.
|
||
* Create a table so we have something to alter.
|
||
* Creating a table by importing a CSV file and altering that table
|
||
* Creating a table using the MySQL workbench tool
|
||
|
||
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.
|
||
|
||
## High level structure of a Relational Database
|
||
|
||
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.
|
||
2. Next is a Schema; a container for the objects needed to managed data in a relational database system.
|
||
3. Objects we create (tables, indexes, stored procedures, functions) to manage the system and its data
|
||
|
||
|
||
|
||
## Creating a MySQL schema
|
||
|
||
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.
|
||
|
||
We’ll create the schema for our learning and testing using the SQL command;
|
||
|
||
```
|
||
create database fCC_alterTableGuide;
|
||
```
|
||
|
||
This instances schema structure prior to running this command
|
||
|
||
|
||
|
||
This instances schema structure after running the SQL statement
|
||
|
||
|
||
|
||
## Creating a table, add test data with "insert", rename the table (alter)
|
||
|
||
We’ll create a Student Table.
|
||
|
||
The steps will be:
|
||
|
||
1. make sure we don’t have the table already
|
||
|
||
|
||
|
||
|
||
2. create the table
|
||
3. insert the test data.
|
||
|
||
* Data Types: the student name is a character field limited to 90 characters
|
||
* 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.
|
||
* There will also be two "time-stamp" fields to play with as well
|
||
|
||
Create statement and display of results from execution;
|
||
|
||
|
||
|
||
Using a Select statement we'll see that the table is there but now records have been added.
|
||
|
||
|
||
|
||
Now to insert some data and see what our new table looks like with records in it (and understand create and update timestamps);
|
||
|
||
|
||
|
||
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.
|
||
|
||
|
||
|
||
## Create a table with the MySql Workbench
|
||
|
||
Right click on the "Tables" under the schema you want the new file placed in. Select Create Table.
|
||
|
||
|
||
|
||
Complete the form as desired and click Apply
|
||
|
||
|
||
|
||
## Create Table as Select (CTAS)
|
||
|
||
A quick way to create a copy of a table, including data is to create table as select.
|
||
|
||
CREATE TABLE my_table as (SELECT * FROM orig_tbl);
|
||
|
||
## Create and populate a table by importing a CSV file
|
||
|
||
Right click on the "Tables" under the schema you want the new file placed in. Select Table Data Import.
|
||
|
||
|
||
|
||
Select the CSV file to import and click NEXT
|
||
Usually you create a new table from the data, select the options desired and click NEXT
|
||
|
||
|
||
|
||
Adjust the data types as needed and click NEXT
|
||
|
||
|
||
|
||
Click NEXT (on this screen and the next one that is displayed) to import the data into the table
|
||
You’ll see completion status, review and click FINISH
|
||
|
||
|
||
|
||
|
||
|
||
|
||
## Other Material
|
||
|
||
There is a lot more detail to cover on this topic so install MySQL and have fun!
|
||
|
||
### Where to get MySQL
|
||
|
||
Try [this download for Windows users[(https://dev.mysql.com/downloads/windows/)
|
||
|
||
|
||
### MySQL documentation
|
||
* <a href='https://dev.mysql.com/doc/refman/5.7/en/alter-table.html' target='_blank' rel='nofollow'>manual page</a>
|
||
* <a href='https://dev.mysql.com/doc/refman/5.7/en/alter-table-examples.html' target='_blank' rel='nofollow'>examples from manual</a>
|
||
|
||
### SQL Server documentation
|
||
* <a href='https://docs.microsoft.com/en-us/sql/t-sql/statements/create-table-transact-sql' target='_blank' rel='nofollow'>Microsoft Docs</a>
|