Handy Mysql Commands

 These are a few handy Mysql commands I have always used. You will find them useful particularly if you are a newbie. Please add more of them in the comments so that it becomes a really useful thread.

 

Please note that below when you see # it means from the Linux/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 "tom" 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 tom@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

or # [mysql dir]/bin/mysqldump -u root -ppassword --all-databases >/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 

• Restore all databases from backup with --all-databases option.

# [mysql dir]/bin/mysql -u root -ppassword < /tmp/alldatabases.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 Statements and clauses

ALTER DATABASE

ALTER TABLE

ALTER VIEW

ANALYZE TABLE

BACKUP TABLE

CACHE INDEX

CHANGE MASTER TO

CHECK TABLE

CHECKSUM TABLE

COMMIT

CREATE DATABASE

CREATE INDEX

CREATE TABLE

CREATE VIEW

DELETE

DESCRIBE

DO

DROP DATABASE

DROP INDEX

DROP TABLE

DROP USER

DROP VIEW

EXPLAIN

FLUSH

GRANT

HANDLER

INSERT

JOIN

KILL

LOAD DATA FROM MASTER

LOAD DATA INFILE

LOAD INDEX INTO CACHE

LOAD TABLE...FROM MASTER

LOCK TABLES

OPTIMIZE TABLE

PURGE MASTER LOGS

RENAME TABLE

REPAIR TABLE

REPLACE

RESET

RESET MASTER

RESET SLAVE

RESTORE TABLE

REVOKE

ROLLBACK

ROLLBACK TO SAVEPOINT

SAVEPOINT

SELECT

SET

SET PASSWORD

SET SQL_LOG_BIN

SET TRANSACTION

SHOW BINLOG EVENTS

SHOW CHARACTER SET

SHOW COLLATION

SHOW COLUMNS

SHOW CREATE DATABASE

SHOW CREATE TABLE

SHOW CREATE VIEW

SHOW DATABASES

SHOW ENGINES

SHOW ERRORS

SHOW GRANTS

SHOW INDEX

SHOW INNODB STATUS

SHOW LOGS

SHOW MASTER LOGS

SHOW MASTER STATUS

SHOW PRIVILEGES

SHOW PROCESSLIST

SHOW SLAVE HOSTS

SHOW SLAVE STATUS

SHOW STATUS

SHOW TABLE STATUS

SHOW TABLES

SHOW VARIABLES

SHOW WARNINGS

START SLAVE

START TRANSACTION

STOP SLAVE

TRUNCATE TABLE

UNION

UNLOCK TABLES

USE

String Functions

AES_DECRYPT

AES_ENCRYPT

ASCII

BIN

BINARY

BIT_LENGTH

CHAR

CHAR_LENGTH

CHARACTER_LENGTH

COMPRESS

CONCAT

CONCAT_WS

CONV

DECODE

DES_DECRYPT

DES_ENCRYPT

ELT

ENCODE

ENCRYPT

EXPORT_SET

FIELD

FIND_IN_SET

HEX

INET_ATON

INET_NTOA

INSERT

INSTR

LCASE

LEFT

LENGTH

LOAD_FILE

LOCATE

LOWER

LPAD

LTRIM

MAKE_SET

MATCH    AGAINST

MD5

MID

OCT

OCTET_LENGTH

OLD_PASSWORD

ORD

PASSWORD

POSITION

QUOTE

REPEAT

REPLACE

REVERSE

RIGHT

RPAD

RTRIM

SHA

SHA1

SOUNDEX

SPACE

STRCMP

SUBSTRING

SUBSTRING_INDEX

TRIM

UCASE

UNCOMPRESS

UNCOMPRESSED_LENGTH

UNHEX

UPPER

Date and Time Functions

ADDDATE

ADDTIME

CONVERT_TZ

CURDATE

CURRENT_DATE

CURRENT_TIME

CURRENT_TIMESTAMP

CURTIME

DATE

DATE_ADD

DATE_FORMAT

DATE_SUB

DATEDIFF

DAY

DAYNAME

DAYOFMONTH

DAYOFWEEK

DAYOFYEAR

EXTRACT

FROM_DAYS

FROM_UNIXTIME

GET_FORMAT

HOUR

LAST_DAY

LOCALTIME

LOCALTIMESTAMP

MAKEDATE

MAKETIME

MICROSECOND

MINUTE

MONTH

MONTHNAME

NOW

PERIOD_ADD

PERIOD_DIFF

QUARTER

SEC_TO_TIME

SECOND

STR_TO_DATE

SUBDATE

SUBTIME

SYSDATE

TIME

TIMEDIFF

TIMESTAMP

TIMESTAMPDIFF

TIMESTAMPADD

TIME_FORMAT

TIME_TO_SEC

TO_DAYS

UNIX_TIMESTAMP

UTC_DATE

UTC_TIME

UTC_TIMESTAMP

WEEK

WEEKDAY

WEEKOFYEAR

YEAR

YEARWEEK

Mathematical and Aggregate Functions

ABS

ACOS

ASIN

ATAN

ATAN2

AVG

BIT_AND

BIT_OR

BIT_XOR

CEIL

CEILING

COS

COT

COUNT

CRC32

DEGREES

EXP

FLOOR

FORMAT

GREATEST

GROUP_CONCAT

LEAST

LN

LOG

LOG2

LOG10

MAX

MIN

MOD

PI

POW

POWER

RADIANS

RAND

ROUND

SIGN

SIN

SQRT

STD

STDDEV

SUM

TAN

TRUNCATE

VARIANCE

Flow Control Functions

CASE

IF

IFNULL

NULLIF

Command-Line Utilities

comp_err

isamchk

make_binary_distribution

msql2mysql

my_print_defaults

myisamchk

myisamlog

myisampack

mysqlaccess

mysqladmin

mysqlbinlog

mysqlbug

mysqlcheck

mysqldump

mysqldumpslow

mysqlhotcopy

mysqlimport

mysqlshow

perror

Perl API - using functions and methods built into the Perl DBI with MySQL

available_drivers

begin_work

bind_col

bind_columns

bind_param

bind_param_array

bind_param_inout

can

clone

column_info

commit

connect

connect_cached

data_sources

disconnect

do

dump_results

err

errstr

execute

execute_array

execute_for_fetch

fetch

fetchall_arrayref

fetchall_hashref

fetchrow_array

fetchrow_arrayref

fetchrow_hashref

finish

foreign_key_info

func

get_info

installed_versions


last_insert_id

looks_like_number

neat

neat_list

parse_dsn

parse_trace_flag

parse_trace_flags

ping

prepare

prepare_cached

primary_key

primary_key_info

quote

quote_identifier

rollback

rows

selectall_arrayref

selectall_hashref

selectcol_arrayref

selectrow_array

selectrow_arrayref

selectrow_hashref

set_err

state

table_info

table_info_all

tables

trace

trace_msg

type_info

type_info_all

Attributes for Handles

PHP API - using functions built into PHP with MySQL

mysql_affected_rows

mysql_change_user

mysql_client_encoding

mysql_close

mysql_connect

mysql_create_db

mysql_data_seek

mysql_db_name

mysql_db_query

mysql_drop_db

mysql_errno

mysql_error

mysql_escape_string

mysql_fetch_array

mysql_fetch_assoc

mysql_fetch_field

mysql_fetch_lengths

mysql_fetch_object

mysql_fetch_row

mysql_field_flags

mysql_field_len

mysql_field_name

mysql_field_seek

mysql_field_table

mysql_field_type

mysql_free_result

mysql_get_client_info

mysql_get_host_info

mysql_get_proto_info

mysql_get_server_info

mysql_info

mysql_insert_id

mysql_list_dbs

mysql_list_fields

mysql_list_processes

mysql_list_tables

mysql_num_fields

mysql_num_rows

mysql_pconnect

mysql_ping

mysql_query

mysql_real_escape_string

mysql_result

mysql_select_db

mysql_stat

mysql_tablename

mysql_thread_id

mysql_unbuffered_query