Computer Code and Tutorials Research

MySQL Basics

Introduction

Welcome. These instructions provide new MySQL users with very basic, step by step, instructions on how to get started.

MySQL runs under a broad array of operating systems. These instructions are guaranteed to work if the following conditions are true:

• You're using Windows NT 4.0 machine and MySQL's Windows executables.
• MySQL is installed on the c: drive in the mysql directory
• MySQL is set to use English

If your conditions are different, the instructions should still work, but keep an eye out for slight differences, like which working directory you'll need to be in.

The commands you need to type are displayed in the bold fixed width font. Resulting screen text is shown here in standard fixed width font.

Contents

• Windows NT 4.0 Installation
• Quick Tips for Other Windows Operating Systems
• Creating a Simple Database and Displaying its Structure
• Putting Data into a Table
• Adding Fields
• Multi-line Command Entry
• Insert Some More Records into the Table
• Updating Existing Records
• Deleting Records
• Time to Call it Quits
• In Closing

If you don't already have MySQL on your system, you'll need to start by getting and installing it.

1. Download MySQL-Win32 version of the program.
2. Open up Windows Explorer.
3. Find the downloaded file and copy it into a temporary directory.
4. Double click on the file. At this point, if you have a zip utility, it should start. If you don't have a program to unzip files, you'll need to get one. I'm partial to PKZIP for Windows.
5. Once the files are extracted, go back into Explorer and double click on Setup.exe.
6. Open up a MS-DOS Prompt window. The default location for starting such windows is: Start Menu | Programs | MS-DOS Prompt.
7. Switch to the c: drive if you're not already there: F:\>c:
8. Switch into the MySQL working directory: C:\>cd mysql\bin
9. Load the MySQL daemon: c:\mysql\bin\mysqld --install
10. Close the DOS Prompt window: c:\mysql\bin\exit
11. Open up the Services Manager by selecting: Start Menu | Settings | Control Panel | Services.
12. Highlight the line with "MySql" on it.
13. Click on the Startup button.
14. Close the Services Manager and the Control Panel.

If you're using Windows 95 or 98, do not run mysqld --install. These operaing systems don't have the ability to host a "service." So, you need to run MySQL as a standalone application by executing the command mysqld --standalone.

I haven't run MySQL on these systems myself, so, for more information, check out the MySQL Mailing List Archive.

Open up a MS-DOS Prompt window

The default location for starting such windows is: Start Menu | Programs | MS-DOS Prompt.

Get to the working directory

F:\>c:
C:\>cd mysql\bin

Instruct MySQL to setup a new database

All this really does is create a new subdirectory in your c:\mysql\data directory.

C:\mysql\bin>mysqladmin create database01
Database "database01" created.

Startup MySQL

C:\mysql\bin>mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 22 to server version: 3.21.29a-gamma-debug

Type 'help' for help.

Open the database

mysql> use database01
Database changed

Create a table

mysql> create table table01 (field01 integer,field02 char(10));
Query OK, 0 rows affected (0.00 sec)

Enclose entire list of field names between one pair of parentheses.
Commas are used between each field.
A space may be used after the comma between fields.
A comma is not used after last field.
This, and all SQL statements, are concluded by a semicolon ";".

List the tables

mysql> show tables;
+----------------------+
| Tables in database01 |
+----------------------+
| table01              |
| table02              |
+----------------------+

List the fields in a table

mysql> show columns from table01;
+---------+----------+------+-----+---------+-------+
| Field   | Type     | Null | Key | Default | Extra |
+---------+----------+------+-----+---------+-------+
| field01 | int(11)  | YES  |     |         |       |
| field02 | char(10) | YES  |     |         |       |
+---------+----------+------+-----+---------+-------+

Congratulations! Pretty straightforward, eh?

Insert a record

mysql> insert into table01 (field01,field02) values (1,'first');
Query OK, 1 row affected (0.00 sec)

Enclose entire list of field names between one pair of parentheses.
Enclose the values to be inserted between another pair of parentheses.
Commas are used between each field and between each value.
A space may be used after the comma between fields.

List all the records in a table

mysql> select * from table01;
+---------+---------+
| field01 | field02 |
+---------+---------+
|       1 | first   |
+---------+---------+

Excellent!

...one field at a time

mysql> alter table table01 add column field03 char(20);
Query OK, 1 row affected (0.04 sec)
Records: 1  Duplicates: 0  Warnings: 0

...more than one at a time

mysql> alter table table01 add column field04 date,add column field05 time;
Query OK, 1 row affected (0.04 sec)
Records: 1  Duplicates: 0  Warnings: 0

The "add column" must be restated for each column.
Commas are used between each add column statement.
A space may be used after these commas.

The MySQL Manual fully explains each possible column data type.

Did it work?

mysql> select * from table01;
+---------+---------+---------+---------+---------+
| field01 | field02 | field03 | field04 | field05 |
+---------+---------+---------+---------+---------+
|       1 | first   | NULL    | NULL    | NULL    |
+---------+---------+---------+---------+---------+

Now we're getting somewhere!

The MySQL command line interface allows you to put a statement on one line or spread it across multiple lines. There's no difference in syntax between the two. Using multiple lines allows you to break down the SQL statement into steps you may more easily comprehend.

In multiple line mode, the interpreter appends each line to the prior lines. This continues until you enter a semicolon ";" to close out the SQL statement. Once the semicolon is typed in and you hit enter, the statement is executed.

Here's an example of the same exact SQL statement entered both ways:

Single Line Entry
mysql> create table table33 (field01 integer,field02 char(30));
Multiple Line Entry
mysql> create table table33 -> (field01 -> integer, -> field02 -> char(30));

Don't break up words:

Valid	Invalid
mysql> create table table33 -> (field01 -> integer, -> field02 -> char(30));	mysql> create table table33 -> (field01 inte -> ger, -> field02 -> char(30));

When inserting or updating records, do not spread a field's string across multiple lines, otherwise the hard returns are stored in the record:

Standard Operation	Hard Return Stored in Record
mysql> insert into table33 (field02) -> values -> ('who thought of foo?');	mysql> insert into table33 (field02) -> values -> ('who thought -> of foo?');
Results
mysql> select * from table33; +---------+---------------------+ | field01 | field02 | +---------+---------------------+ | NULL | who thought of foo? | | NULL | who thought of foo? | +---------+---------------------+

Add this record

mysql> insert into table01 (field01,field02,field03,field04,field05) values
    -> (2,'second','another','1999-10-23','10:30:00');
Query OK, 1 row affected (0.00 sec)

Quotes must go around text values.

Standard date format is "yyyy-mm-dd".
Standard time format is "hh:mm:ss".
Quotes are required around the standard date and time formats, noted above.
Dates may also be entered as "yyyymmdd" and times as "hhmmss". If entered in this format, values don't need to be quoted.

Numeric values do not need to be quoted. This holds true regardless of the data type a column is formatted to contain (e.g. text, date, time, integer).

MySQL has a useful command buffer. The buffer stores the SQL statements you've entered thus far. Using it keeps you from having to retype the same commands over and over. Let's use this next step as an example.

Add another record using the command buffer (and optional date and time formats)

1. Hit the up arrow key twice.
2. Hit the ENTER key.
3. Type in the new values between a pair parentheses and stick a closing semicolon on the end.
   (3,'a third','more foo for you',19991024,103004);
4. Hit the ENTER key.

Voilą!

Is it in there?

mysql> select * from table01;
+---------+-----------+------------------+------------+----------+
| field01 | field02   | field03          | field04    | field05  |
+---------+-----------+------------------+------------+----------+
|       1 | first     | NULL             | NULL       | NULL     |
|       2 | second    | another          | 1999-10-23 | 10:30:00 |
|       3 | a third   | more foo for you | 1999-10-24 | 10:30:01 |
+---------+-----------+------------------+------------+----------+

It's in there!

Now, we're almost done...

Modify one field at a time

Again, be careful with syntax. Quote marks need to go around text but not around numbers.

mysql> update table01 set field03='new info' where field01=1;
Query OK, 1 row affected (0.00 sec)

Change multiple fields at once

Remember to put commas between each field you're updating.

mysql> update table01 set field04=19991022, field05=062218 where field01=1;
Query OK, 1 row affected (0.00 sec)

So, what's up with our data?

mysql> select * from table01;
+---------+-----------+------------------+------------+----------+
| field01 | field02   | field03          | field04    | field05  |
+---------+-----------+------------------+------------+----------+
|       1 | first     | new info         | 1999-10-22 | 06:22:18 |
|       2 | second    | another          | 1999-10-23 | 10:30:00 |
|       3 | third one | more foo for you | 1999-10-24 | 10:30:01 |
+---------+-----------+------------------+------------+----------+

Update multiple records in one stroke

mysql> update table01 set field05=152901 where field04>19990101;
Query OK, 3 rows affected (0.00 sec)

Survey says...

mysql> select * from table01;
+---------+-----------+------------------+------------+----------+
| field01 | field02   | field03          | field04    | field05  |
+---------+-----------+------------------+------------+----------+
|       1 | first     | new info         | 1999-10-22 | 15:29:01 |
|       2 | second    | another          | 1999-10-23 | 15:29:01 |
|       3 | third one | more foo for you | 1999-10-24 | 15:29:01 |
+---------+-----------+------------------+------------+----------+

Wee haw!

The delete command

mysql> delete from table01 where field01=3;
Query OK, 1 row affected (0.01 sec)

mysql> select * from table01;
+---------+---------+----------+------------+----------+
| field01 | field02 | field03  | field04    | field05  |
+---------+---------+----------+------------+----------+
|       1 | first   | new info | 1999-10-22 | 15:29:01 |
|       2 | second  | another  | 1999-10-23 | 15:29:01 |
+---------+---------+----------+------------+----------+

mysql> quit
Bye

Now you know some rudimentary commands for running a database in MySQL. Since MySQL is operated by executing SQL calls, you have a broad array of very powerful tools at your disposal. For instance, you're able to display data from several tables at once by joining related fields. Similarly, SQL permits complex displays, updates or deletions of multiple records which fit specific criteria. So, your next step toward mastery is learning all about SQL.

James Hoffman has put a tutorial page up on the web entitled Introduction to Structured Query Language. The General SQL Information of the MySQL Manual lists books recommended by many members of their mailing list. Yahoo may have some helpful materials as well.

Another thing to note is MySQL offers good security features you'll need to use when operating on networks. For further information on security and other MySQL features, check out the MySQL web site:

• Home Page
• The Manual
• Documentation
• Resources

Don't Write Me!

Folks, please note a few things:

1. I am not the company that makes MySQL. It's made by TcX.
2. I am not on the development team.
3. I put this page up here to help people. But, this is all the help you are going to get from me on the subject of MySQL.

If you need further assistance, check out the MySQL web site. Also, the MySQL Mailing List Archive is a tremendous resource.