MYSQL(CLASS 8)

Create, List, Use and Delete Databases Commands
create databaseThis command is used to create a Database on the sql server..Syntax: create [db name];Eg:create employees; show databases This command id used to list all databases on the sql server.Syntax: show databases;use database This command is used to switch to a database.Syntax: use [db name];
drop databaseThis command is used to delete a database. Syntax: drop [db name];
Creating tables and working with it
create tabeThis command is used to create tables in a database.Eg: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));show tablesThis command is see all the tables in the database.describe tableTo see database's field formats.describe [table name];
drop tableTo delete a table.drop table [table name];
Show all data in a table.SELECT * FROM [table name];
Returns the columns and column information pertaining to the designated table.show columns from [table name];
Show certain selected rows with the value "something".SELECT * FROM [table name] WHERE [field name] = "something";
Show all records containing the name "Telson" AND the phone number '2255'.SELECT * FROM [table name] WHERE name = "Telson" AND phone_number = '2255';
Show all records not containing the name "Telson" AND the phone number '2255' order by the phone_number field.SELECT * FROM [table name] WHERE name != "Telson" AND phone_number = '2255' order by phone_number;
Show all records starting with the letters 'Tel' AND the phone number '2255'.SELECT * FROM [table name] WHERE name like "Tel%" AND phone_number = '2255';
Use a regular expression to find records. Use "REGEXP BINARY" to force case-sensitivity. This finds any record beginning with a. SELECT * FROM [table name] WHERE rec RLIKE "^a$";
Show unique records.SELECT DISTINCT [column name] FROM [table name];
Show selected records sorted in an ascending (asc) or descending (desc).SELECT [column1],[column2] FROM [table name] ORDER BY [column2] DESC;
Return number of rows.SELECT COUNT(*) FROM [table name];
Sum column.SELECT SUM(*) FROM [table name];
Join tables on common columns.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 Mysql databse Users and changing Password
Switch to the mysql db. Create a new user.INSERT INTO [table name] (Host,User,Password) VALUES('%','user',PASSWORD('password'));
Change a users password.(from unix shell).[mysql dir] mysqladmin -u root -h hostname.blah.org -p password 'new-password'
Change a users password.(from MySQL prompt).SET PASSWORD FOR 'user'@'hostname' = PASSWORD('passwordhere');
Allow the user "telson" to connect to the server from localhost using the password "passwd"grant usage on *.* to telson@localhost identified by 'passwd';
Switch to mysql db.Give user privilages for a db.INSERT INTO [table name] (Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv) VALUES ('%','databasename','username','Y','Y','Y','Y','Y','N');
or
grant all privileges on databasename.* to username@localhost;
Modifying and Updating tables in MySQL
To update info already in a table.UPDATE [table name] SET Select_priv = 'Y',Insert_priv = 'Y',Update_priv = 'Y' where [field name] = 'user';
Delete a row(s) from a table.DELETE from [table name] where [field name] = 'something';
Update database permissions/privilages.FLUSH PRIVILEGES;
Delete a column.
alter table [table name] drop column [column name];
Add a new column to db.alter table [table name] add column [new column name] varchar (20);
Change column name.alter table [table name] change [old column name] [new column name] varchar (50);
Make a unique column so you get no dupes.alter table [table name] add unique ([column name]);
Make a column bigger.alter table [table name] modify [column name] VARCHAR(4);
Delete unique from table.alter table [table name] drop index [colmn name];
Load a CSV file into a table.LOAD DATA INFILE '/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' (field1,field2,field3);
Creating MySQL Database backup’s and Restoring Databases
Dump all databases for backup. Backup file is sql commands to recreate all db's.[mysql dir] mysqldump -u root -ppassword --opt >/tmp/alldatabases.sql
Dump one database for backup.[mysql dir] mysqldump -u username -ppassword --databases databasename >/tmp/databasename.sql
Dump a table from a database.[mysql dir] mysqldump -c -u username -ppassword databasename tablename > /tmp/databasename.tablename.sql
Restore database (or database table) from backup.[mysql dir] mysql -u username -ppassword databasename < /tmp/databasename.sql
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