Files
freeCodeCamp/guide/english/sql/sql-create-table/index.md

120 lines
4.6 KiB
Markdown
Raw Normal View History

2018-10-12 15:37:13 -04:00
---
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, its 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.
Well create the schema for our learning and testing using the SQL command;
```sql
2018-10-12 15:37:13 -04:00
create database fCC_alterTableGuide;
```
* ## Creating a table, add test data with "insert".
2018-10-12 15:37:13 -04:00
Well create a Student Table.
2018-10-12 15:37:13 -04:00
The steps will be:
2018-10-12 15:37:13 -04:00
1. make sure we dont have the table already
2. create the table
3. insert the test data.
2018-10-12 15:37:13 -04:00
Data Types: the student name is a character field limited to 90 characters. <br/>
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.<br/>
There will also be two "time-stamp" fields to play with as well.
2018-10-12 15:37:13 -04:00
Let's create a student table statement.
2018-10-12 15:37:13 -04:00
```sql
create table student(
studentId int(11) not null primary key ,
FullName varchar(90),
sat_score int(4),
ts1 timestamp,
ts2 timestamp default current_timestamp,
programOfStudy varchar(200)
);
```
2018-10-12 15:37:13 -04:00
Now to insert some data and see what our new table looks like with records in it.
```sql
insert into student(studentId, FullName,sat_score,ts1,ts2,programOfStudy)
values(1, "Lorah sey", 400 ,now(),now(),"programming");
--to display records in table
select * from student;
2018-10-12 15:37:13 -04:00
```
Result :
```text
+-----------+----------------+-----------+---------------------+----------------------+----------------+
| studentId | FullName | sat_score | ts1 | ts2 | programOfStudy |
+-----------+----------------+-----------+---------------------+----------------------+----------------+
| 1 | Lorah sey | 400 | 2019-04-28 13:55:11 | 2019-04-28 13:55:11 | programming |
+-----------+----------------+-----------+---------------------+----------------------+----------------+
2018-10-12 15:37:13 -04:00
```
2018-10-12 15:37:13 -04:00
* ## Create a table with the MySql Workbench
2018-10-12 15:37:13 -04:00
* 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
2018-10-12 15:37:13 -04:00
* ## Create Table as Select (CTAS)
2018-10-12 15:37:13 -04:00
A quick way to create a copy of a table, including data is to create table as select.
```sql
CREATE TABLE my_table as (SELECT * FROM orig_tbl);
```
2018-10-12 15:37:13 -04:00
* ## Create and populate a table by importing a CSV file
2018-10-12 15:37:13 -04:00
* 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 to import the data into the table
* Youll see completion status, review and click FINISH
2018-10-12 15:37:13 -04:00
## Other Material
There is a lot more detail to cover on this topic so install MySQL and have fun!
2018-10-12 15:37:13 -04:00
### 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>