120 lines
4.6 KiB
Markdown
120 lines
4.6 KiB
Markdown
---
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title: SQL Create Table
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---
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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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```sql
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create database fCC_alterTableGuide;
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```
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* ## Creating a table, add test data with "insert".
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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. <br/>
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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.<br/>
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There will also be two "time-stamp" fields to play with as well.
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Let's create a student table statement.
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```sql
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create table student(
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studentId int(11) not null primary key ,
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FullName varchar(90),
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sat_score int(4),
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ts1 timestamp,
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ts2 timestamp default current_timestamp,
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programOfStudy varchar(200)
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);
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```
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Now to insert some data and see what our new table looks like with records in it.
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```sql
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insert into student(studentId, FullName,sat_score,ts1,ts2,programOfStudy)
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values(1, "Lorah sey", 400 ,now(),now(),"programming");
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--to display records in table
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select * from student;
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```
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Result :
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```text
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+-----------+----------------+-----------+---------------------+----------------------+----------------+
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| studentId | FullName | sat_score | ts1 | ts2 | programOfStudy |
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+-----------+----------------+-----------+---------------------+----------------------+----------------+
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| 1 | Lorah sey | 400 | 2019-04-28 13:55:11 | 2019-04-28 13:55:11 | programming |
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+-----------+----------------+-----------+---------------------+----------------------+----------------+
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```
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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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```sql
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CREATE TABLE my_table as (SELECT * FROM orig_tbl);
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```
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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 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 is a lot more detail to cover on 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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