My SQL Commands

This is a list of handy MySQL commands that I use time and time again. At the bottom are statements, clauses, and functions you can use in MySQL. Below that are PHP and Perl API functions you can use to interface with MySQL. To use those you will need to build PHP with MySQL functionality. To use MySQL with Perl you will need to use the Perl modules DBI and DBD::mysql. Below when you see # it means from the unix shell. When you see mysql> it means from a MySQL prompt after logging into MySQL. To login (from unix shell) use -h only if needed. # [mysql dir]/bin/mysql -h hostname -u root -p Create a database on the sql server. mysql> create database [databasename]; List all databases on the sql server. mysql> show databases; Switch to a database. mysql> use [db name]; To see all the tables in the db. mysql> show tables; To see database's field formats. mysql> describe [table name]; To delete a db. mysql> drop database [database name]; To delete a table. mysql> drop table [table name]; Show all data in a table. mysql> SELECT * FROM [table name];

Returns the columns and column information pertaining to the designated table. mysql> show columns from [table name]; Show certain selected rows with the value "whatever". mysql> SELECT * FROM [table name] WHERE [field name] = "whatever"; Show all records containing the name "Bob" AND the phone number '3444444'. mysql> SELECT * FROM [table name] WHERE name = "Bob" AND phone_number = '3444444'; Show all records not containing the name "Bob" AND the phone number '3444444' order by the phone_number field. mysql> SELECT * FROM [table name] WHERE name != "Bob" AND phone_number = '3444444' order by phone_number; Show all records starting with the letters 'bob' AND the phone number '3444444'. mysql> SELECT * FROM [table name] WHERE name like "Bob%" AND phone_number = '3444444'; Show all records starting with the letters 'bob' AND the phone number '3444444' limit to records 1 through 5. mysql> SELECT * FROM [table name] WHERE name like "Bob%" AND phone_number = '3444444' limit 1,5; Use a regular expression to find records. Use "REGEXP BINARY" to force case-sensitivity. This finds any record beginning with a. mysql> SELECT * FROM [table name] WHERE rec RLIKE "^a"; Show unique records. mysql> SELECT DISTINCT [column name] FROM [table name]; Show selected records sorted in an ascending (asc) or descending (desc). mysql> SELECT [col1],[col2] FROM [table name] ORDER BY [col2] DESC; Return number of rows.

mysql> SELECT COUNT(*) FROM [table name]; Sum column. mysql> SELECT SUM(*) FROM [table name]; Join tables on common columns. mysql> select lookup.illustrationid, lookup.personid,person.birthday from lookup left join person on lookup.personid=person.personid=statement to join birthday in person table with primary illustration id; Creating a new user. Login as root. Switch to the MySQL db. Make the user. Update privs. # mysql -u root -p mysql> use mysql; mysql> INSERT INTO user (Host,User,Password) VALUES('%','username',PASSWORD('password')); mysql> flush privileges; Change a users password from unix shell. # [mysql dir]/bin/mysqladmin -u username -h hostname.blah.org -p password 'new-password' Change a users password from MySQL prompt. Login as root. Set the password. Update privs. # mysql -u root -p mysql> SET PASSWORD FOR 'user'@'hostname' = PASSWORD('passwordhere'); mysql> flush privileges; Recover a MySQL root password. Stop the MySQL server process. Start again with no grant tables. Login to MySQL as root. Set new password. Exit MySQL and restart MySQL server. # /etc/init.d/mysql stop # mysqld_safe --skip-grant-tables & # mysql -u root mysql> use mysql; mysql> update user set password=PASSWORD("newrootpassword") where User='root'; mysql> flush privileges; mysql> quit # /etc/init.d/mysql stop # /etc/init.d/mysql start Set a root password if there is on root password.

# mysqladmin -u root password newpassword Update a root password. # mysqladmin -u root -p oldpassword newpassword Allow the user "bob" to connect to the server from localhost using the password "passwd". Login as root. Switch to the MySQL db. Give privs. Update privs. # mysql -u root -p mysql> use mysql; mysql> grant usage on *.* to bob@localhost identified by 'passwd'; mysql> flush privileges; Give user privilages for a db. Login as root. Switch to the MySQL db. Grant privs. Update privs. # mysql -u root -p mysql> use mysql; mysql> INSERT INTO db (Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv) VALUES ('%','databasename','username','Y','Y','Y','Y','Y','N'); mysql> flush privileges; or mysql> grant all privileges on databasename.* to username@localhost; mysql> flush privileges; To update info already in a table. mysql> UPDATE [table name] SET Select_priv = 'Y',Insert_priv = 'Y',Update_priv = 'Y' where [field name] = 'user'; Delete a row(s) from a table. mysql> DELETE from [table name] where [field name] = 'whatever'; Update database permissions/privilages. mysql> flush privileges; Delete a column. mysql> alter table [table name] drop column [column name];

Add a new column to db. mysql> alter table [table name] add column [new column name] varchar (20); Change column name. mysql> alter table [table name] change [old column name] [new column name] varchar (50); Make a unique column so you get no dupes. mysql> alter table [table name] add unique ([column name]); Make a column bigger. mysql> alter table [table name] modify [column name] VARCHAR(3); Delete unique from table. mysql> alter table [table name] drop index [colmn name]; Load a CSV file into a table. mysql> LOAD DATA INFILE '/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' (field1,field2,field3); Dump all databases for backup. Backup file is sql commands to recreate all db's. # [mysql dir]/bin/mysqldump -u root -ppassword --opt >/tmp/alldatabases.sql Dump one database for backup. # [mysql dir]/bin/mysqldump -u username -ppassword --databases databasename >/tmp/databasename.sql Dump a table from a database. # [mysql dir]/bin/mysqldump -c -u username -ppassword databasename tablename > /tmp/databasename.tablename.sql Restore database (or database table) from backup. # [mysql dir]/bin/mysql -u username -ppassword databasename < /tmp/databasename.sql

Create Table Example 1. mysql> CREATE TABLE [table name] (firstname VARCHAR(20), middleinitial VARCHAR(3), lastname VARCHAR(35),suffix VARCHAR(3),officeid VARCHAR(10),userid VARCHAR(15),username VARCHAR(8),email VARCHAR(35),phone VARCHAR(25), groups VARCHAR(15),datestamp DATE,timestamp time,pgpemail VARCHAR(255)); Create Table Example 2. mysql> create table [table name] (personid int(50) not null auto_increment primary key,firstname varchar(35),middlename varchar(50),lastnamevarchar(50) default 'bato');

MySQL Commands List Here you will find a collection of basic MySQL statements that should prove useful for basic CRUDS operations (create, replace, update, delete, select). There may be some issues with the kind of quotes you use around your data. If you are having difficulties, try using singe quotes ( ' ) or tricky quotes ( ` -- on keyboard key next to number 1) around your data. One or the other is bound to work. The following statements are covered in this page: CREATE DATABASE CREATE TABLE INSERT REPLACE UPDATE SELECT DELETE VALUES SET WHERE IN AND OR RLIKE DISTINCT MAX CREATE DATABASE CREATE DATABASE database_name ; Will create a MySQL database. You may have to ensure that the user you used to log in has enough privileges to create databases. Some web hosting companies do not allow their customers to create databases -- as they have already created a couple databases for you. In this case you should already have enough privy's

to create tables on the already created databases. Check with your hosting provider to see what the proper database names are and what the usernames and passwords are for the database(s). Example: CREATE DATABASE myMediaLibrary;

CREATE TABLE Create a table on the database you are currently logged into. Example: CREATE TABLE IF NOT EXISTS `music` ( `id` int(8) unsigned NOT NULL, `artist` text NOT NULL, `album` text NOT NULL, `title` text NOT NULL, `track` text NOT NULL, `year` varchar(8) NOT NULL, PRIMARY KEY (`id`), FULLTEXT KEY `artist` (`artist`), FULLTEXT KEY `album` (`album`), FULLTEXT KEY `title` (`title`), FULLTEXT KEY `track` (`track`), FULLTEXT KEY `year` (`year`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 ; The table set up will be similar to: id

artist album

title

tr y ac e k ar

NOTE: You may want to use AUTO INCREMENT to have MySQL automatically maintain the id field when you add a new item to the table. This is up to you on how you would like to

maintain the id., which in this case is the "PRIMARY KEY" which needs to be unique and is what MySQL needs to keep things orderly: CREATE TABLE IF NOT EXISTS `music` ( `id` int(8) unsigned NOT NULL AUTO_INCREMENT, `artist` text NOT NULL, `album` text NOT NULL, `title` text NOT NULL, `track` text NOT NULL, `year` varchar(8) NOT NULL, PRIMARY KEY (`id`), FULLTEXT KEY `artist` (`artist`), FULLTEXT KEY `album` (`album`), FULLTEXT KEY `title` (`title`), FULLTEXT KEY `track` (`track`), FULLTEXT KEY `year` (`year`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ; Refer to the MySQL documentation for more info on defining column data types.

INSERT STATEMENTS INSERT INTO table_name ( `col_A`, `col_B`, `col_C`) VALUES ( `col_A_data`, `col_B_data`, `col_C_data`) ; Inserts a row into the table using the data defined in the VALUES section. As you can see, the column names are established within the first set of parenthesis, the order of the data in the second set of parenthesis must match the order of the column names defined int he first set of parentheses. Example: INSERT INTO music ( 'id', `artist`, `album`) VALUES ( '1', `the beatles`, `Abbey Road`);

Puts a row into the database tables as: id

artist album

1

the beatles

title

tr y ac e k ar

Abbey Road

I've color coded each "pair" so you can see that the data "col_B_data' that is going to go into column name "col_B" must be second. if there is no data available for col_B, use empty single quotes as: INSERT INTO table_name ( `col_A`, `col_B`, `col_C`) VALUES ( `col A data `, ``, `col C data`) ; Example: INSERT INTO music ( 'id', `artist`, `album`) VALUES ( '1', ``, `Abbey Road`); Puts a row into the database tables as: id

artist album

1

title

tr y ac e k ar

Abbey Road

REPLACE STATEMENTS REPLACE INTO table_name ( `col_A`, `col_B`) VALUES ( `col A data`, `col B data`) ; Replaces items in a row. This action is dependant on the "id" because all tables need to have at least one "unique" column. Meaning that one of the columns must be used to provide row data that is unique to each row. In this example, "id" is the unique row.

Example: REPLACE INTO music ( 'id', `artist`, `album`) VALUES ( '1', `the beatles`, `abbey road`); Puts a row into the database tables as: id

artist album

1

the beatles

title

tr y ac e k ar

Abbey Road

As you can see, we've just replaced the empty "artist" with the new data of "the beatles" REPLACE behaves much like INSERT except that if the "unique column" is supplied, the existing row will be updated, if the "unique column" is not provided, a new row will be added. Example: REPLACE INTO music ( `artist`, `album`) VALUES ( `the beatles`, `abbey road`); Puts a new row into the database tables as: id

artist album

1

the beatles

Abbey Road

the beatles

Abbey Road

title

tr y ac e k ar

NOTE: You may get errors when trying this kind of REPLACE, because usually the "unique column" can not be null (or empty). Some people like to set up the database where the "unique column" is automatically incremented by MySQL. This is kind of confusing and can lead to a headache. So just remember to include the "unique column" when using the REPLACE statement, or you'll get duplicate rows... OR use the UPDATE statement.

UPDATE STATEMENTS UPDATE table_name SET col_B='new_data' WHERE col_A='reference_data' ; Will update a row's columns with the new values specified in the SET section and the row to update is specified by the WHERE section Example: UPDATE music SET title='Come Together' WHERE id=1; Notice that quotes are not around the id-1. This is because you shouldn't have to use quotes when you are entering an integer. id

1

artist

the beatles

album

title

Abbey Road

Come Together

tr y ac e k ar

To update two or more columns, separate value pairs in the SET section with a comma Example: UPDATE music SET track='1', year='1969' WHERE id=1; Notice that quotes are not around the id-1. This is because you shouldn't have to use quotes when you are entering an integer. id

1

artist

the beatles

album

title

Abbey Road

Come Together

tr y ac e k ar 1

19 69

It may seem frustrating to see that quotes were used around the "integers' in the SET section, but not in the WHERE section. Sometimes you may need to use them, but sometimes you do not. A llot of it depends on how the database was originally set up. If we initially set up the database where "track" and "year" did not use TEXT, but rather INT(11) we could probably get away with

not using quotes around the data in the SET section. This issue also has to do with how MySQL is set up on your server. Another thing to consider is that because we're using single quotes around the data that we are entering... what if your data contains a single quote? Such as: UPDATE music SET title='Mike's Song' WHERE id=1; As you can see, now there are three single quotes, and chances are MySQL will return an error. There are two things you can try. 1. Escape the single quote in the data as: UPDATE music SET title='Mike\'s Song' WHERE id=1; 1. Use tricky quotes: UPDATE music SET title=`Mike's Song` WHERE id=1; Tricky quotes are just above the "tab" button on your keyboard.

SELECT STATEMENTS SELECT * FROM table_name WHERE 1 ; Returns all rows and all columns from table_name.. All rows is specified by the * (asterisk) symbol between SELECT and FROM. Example: SELECT * FROM music WHERE 1; Returns: id

artist

album

title

tr y ac e

k ar 1

2

3

4

5

6

7

8

9

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

the

Abbey Road

Something

Abbey Road

Maxwell's Silver Hammer

2

1 9 6 9

3

1 9 6 9

4

1 9 6 9

5

1 9 6 9

6

1 9 6 9

7

1 9 6 9

8

1 9 6 9

9

1

Oh! Darling

Abbey Road

Octopus's Garden

Abbey Road

I Want You (She's So Heavy)

Abbey Road

1 9 6 9

Come Together

Abbey Road

Abbey Road

1

Here Comes the Sun

Abbey Road

Because

Abbey Road

You Never Give Me Your

beatles Money

10

11

12

13

14

15

16

17

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

the beatles

9 6 9

Sun King

10 1 9 6 9

Mean Mr. Mustard

11 1 9 6 9

Abbey Road

Polythene Pam

12 1 9 6 9

Abbey Road

She Came in Through the Bathroom Window

13 1 9 6 9

Golden Slumbers

14 1 9 6 9

Carry That Weight

15 1 9 6 9

Abbey Road

The End

16 1 9 6 9

Abbey Road

Her Majesty

Abbey Road

Abbey Road

Abbey Road

Abbey Road

17 1 9 6

9 18

beatles Rubber Soul

19

20

21

22

23

24

25

26

1 9 6 9

5

1 9 6 9

6

1 9 6 9

7

1 9 6 9

8

1 9 6 9

9

1

Michelle

beatles

beatles

4

The Word

beatles Rubber Soul

1 9 6 9

Think for Yourself

beatles Rubber Soul

3

Nowhere Man

beatles Rubber Soul

1 9 6 9

You Won't See Me

beatles Rubber Soul

2 Norwegian Wood (This Bird Has Flown)

beatles Rubber Soul

1 9 6 9

Drive My Car

beatles Rubber Soul

1

Rubber Soul

What Goes On

Rubber Soul

Girl

9 6 9 27

28

29

beatles Rubber Soul

10 1 9 I'm Looking Through You 6 9

Rubber Soul

In My Life

11 1 9 6 9

Wait

12 1 9 6 9

If I Needed Someone

13 1 9 6 9

Run for Your Life

14 1 9 6 9

beatles

beatles Rubber Soul

30

beatles Rubber Soul

31

beatles Rubber Soul

SELECT * FROM table_name WHERE column_name IN ('data_1','data_2') ; Returns all rows* and all columns that have matching data specified in the IN section. The data defined in the IN section must match exactly. NOTE: All rows is specified by the * symbol between SELECT and FROM sections. Example: SELECT * FROM music WHERE track IN ('1','2'); Returns:

id

artist album

title

1

the beatles

Abbey Road

Come Together

2

the beatles

Abbey Road

Something

18

beatles

Rubber Soul

Drive My Car

19

beatles

Rubber Soul

Norwegian Wood (This Bird Has Flown)

tr y ac e k ar 1

19 69

2

19 69

1

19 69

2

19 69

SELECT col_A_name, col_B_name FROM table_name WHERE col_B_name='search_term' ; Returns only two columns from the matching row. The data defined int eh WHERE section must match exactly. Example: SELECT artist, album FROM music WHERE title='You Never Give Me Your Money'; Returns: artist

album

the beatles

Abbey Road

SELECT col_A_name, col_B_name FROM table_name WHERE col_B_name IN ('search_term_1','search_term_2') ; Returns only two columns that match the data defined in the IN section.

Example: SELECT title, album FROM music WHERE title='You Won\'t See Me', 'I\'m Looking Through You'; NOTE: Notice that the single quotes are "escaped" by using a back slash within the data. You may want to try using tricky quotes instead as: SELECT album, date FROM music WHERE title=`You Won't See Me`, `I'm Looking Through You`; Returns: album

date

Rubber Soul

1969

Rubber Soul

1969

SELECT * FROM table_name WHERE col_A_name RLIKE ('search_termA') OR col_B_name RLIKE ('search_termB') ; This example will search through your table for matching words. Will return all rows that contain either search_termA OR search_term_B -- the search term can be a single word or a phrase. NOTE: This options is based on having MySQL set up to take advantage of FULLTEXT, which was established when we set up the table. Also note that some MySQL configurations will not return matches on words that are shorter than 4 characters. So for this example, MySQL may not return anything. So you may want to experiment with this kind of search with a larger word such as "Yourself." NOTE 2: This is actually the old way to do things, but more reliable than the new method. The new method uses the MATCH statement, but requires some additional configuration on your MySQL installation / server. The method offered here is probably a little more reliable as of this writing. NOTE TO SELF: If the year is 2013, you may have better luck using the MATCH statement. I'm sure I'll be dead by then, so your on your own. Check with the MySQL documentation.

Example: SELECT * FROM music WHERE title RLIKE ('you') OR title RLIKE ('mustard') ; Returns: id

artist album

title

tr y ac e k ar

6

the beatles

Abbey Road

I Want You (She's So Heavy)

6

19 69

9

the beatles

Abbey Road

You Never Give Me Your Money

9

19 69

20

beatles

Rubber Soul

You Won't See Me

3

19 69

27

beatles

Rubber Soul

I'm Looking Through You

10 19 69

11

the beatles

Abbey Road

Mean Mr. Mustard

11 19 69

SELECT * FROM table_name WHERE col_A_name RLIKE ('search_termA') AND col_B_name RLIKE ('search_termB') ; This example will search through your table for matching words. Will return all rows that contain either search_termA OR search_term_B -- the search terms can be a single word or a phrase.

Example: SELECT * FROM music WHERE title RLIKE ('you') AND title RLIKE ('me') ;

Returns: id

artist

9

the beatles

20

beatles

album

title

Abbey Road

You Never Give Me Your Money

Rubber Soul

You Won't See Me

tr y ac e k ar 9

19 69

3

19 69

NOTE: In this example, we are only searching within the same column, you can search different columns if you want, and you can also add more OR or AND statements, or you can mix and match OR and AND statements to refine the search.. Example: SELECT * FROM music WHERE title RLIKE ('you') OR artist RLIKE ('the') AND track RLIKE ('1969'); SELECT * FROM table_name WHERE 1 ORDER BY RAND() LIMIT number_of_rows_to_return ; Will select random rows and limit the number of rows returned to the number specified in the LIMIT section. Example: SELECT * FROM music WHERE 1 ORDER BY RAND() LIMIT 3; Returns something similar to : (Can't be too sure here, since MySQL is picking rows randomly, but you can see that only three rows are returned :) id

25

artist

beatles

album

title

tr y ac e k ar

Rubber Soul

What Goes On

8

1 9

6 9 13

5

the beatles

the beatles

Abbey Road

She Came in Through the Bathroom Window

13 1 9 6 9 5

Abbey Road

Octopus's Garden

1 9 6 9

SELECT DISTINCT col_A FROM table_name WHERE 1; Will only return rows that have unique data in the column specified. Perhaps the best way to explain this is through example. If we do something like this: SELECT DISTINCT year FROM music WHERE 1; ... we will only get one row and one column because all the rows in our table have "1969" set as the year. MySQL will pick the first unique row, all subsequent rows that have the same data in the specified column will not be returned, because the data in the other rows is not unique. y e a r 1 9 6 9

If we do something like: SELECT DISTINCT artist FROM music WHERE 1;

We'll only get two rows: artist the beatles beatles

... because the for the first album, we used "the beatles" whereas the second album, we just used "beatles" -- so only the first row that MySQL encounters with unique data in the "artist" column will be returned... because the rest of the rows are not unique.

SELECT DISTINCT col_A,col_B FROM table_name WHERE 1 ORDER BY RAND() LIMIT number_of_rows_to_return ; You can add the DISTINCT statement to any statement. So that only unique items are returned. Or another way to think about it is that no duplicate rows are returned. For example, if you used the RLIKE statement to look for a couple key words, MySQL may return the dame row two times, you can use the DISTINCT statement to filter only unique rows. Example: SELECT DISTINCT artist,album FROM music WHERE 1 ORDER BY RAND() LIMIT 5; This example is deviating slightly from out standard "All beatles" table, in this example, we'll have to imaging that our tables contains a whole bunch of artists and albums. So, with your imagination flying, the example above would return 5 rows, where both the artist and album are unique. artist

album

beatles

Rubber Soul

the beatles

Abbey Road

Ray Lamontagne

Trouble

The Tragically Hip

Wheat kings

The Police

Outlandos d'Amour

NOTE: Yes, both "the beatles" and "beatles" albums would be returned because the entire data contained in the "artist" column is unique for both of these albums. SELECT MAX(col_A) FROM table_name ; Will return the highest value for that column. Usually you want to sue this on a column that references a number. For example, let's say you wanted to find the highest ID on your table so that you could determine the next ID to use fro a new item that you are inserting into your tables. You could use the MAX statement to find the largest ID number, then when you INSERT your new item, you can simply bump up the number by one. Example: SELECT MAX(id) FROM music; Returns: id 31

... because the highest ID in our table is 31. e.g. there are 31 items in our table as defined by the ID column. If we ran something like: SELECT MAX(track) FROM music ; ... we'd get: track 17

... because 17 is the highest number in the "track" column

DELETE STATEMENTS DELETE FROM table_name WHERE column_name='search_data'; Will remove rows that match the search data defined in the WHERE section Example: DELETE FROM music WHERE artist='the beatles'; Will remove all rows that have "the beatles" defined in the "artist" column. DELETE FROM table_name WHERE column_name IN ('search_data_A', 'search_data_B'); Will remove all rows that match the search data defined in the IN section. Example: DELETE FROM music WHERE artist IN ('the beatles', 'beatles'); ... will remove all the items from our example table