ഡാറ്റാബേസ് അഡ്മിനിസ്ട്രേറ്റർമാർക്കുള്ള 15 അടിസ്ഥാന MySQL അഭിമുഖ ചോദ്യങ്ങൾ
ഈ ലേഖനത്തിന് മുമ്പ്, 'ലിനക്സ് ഇന്റർവ്യൂ' വിഭാഗത്തിൽ മൂന്ന് ലേഖനങ്ങൾ ഇതിനകം പ്രസിദ്ധീകരിച്ചിട്ടുണ്ട്, അവയെല്ലാം ഞങ്ങളുടെ ശ്രദ്ധേയരായ വായനക്കാർ വളരെയധികം അഭിനന്ദിച്ചു, എന്നിരുന്നാലും ഈ സംവേദനാത്മക പഠന പ്രക്രിയ, വിഭാഗം തിരിച്ചുള്ളതാക്കുന്നതിനുള്ള ഫീഡ്uബാക്ക് ഞങ്ങൾക്ക് ലഭിച്ചുകൊണ്ടിരുന്നു. ആശയം മുതൽ പ്രവർത്തനം വരെ, ഞങ്ങൾ നിങ്ങൾക്ക് 15 MySQL അഭിമുഖ ചോദ്യങ്ങൾ നൽകുന്നു.
[email :/home/avi# service mysql status /usr/bin/mysqladmin Ver 8.42 Distrib 5.1.72, for debian-linux-gnu on i486 Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Server version 5.1.72-2 Protocol version 10 Connection Localhost via UNIX socket UNIX socket /var/run/mysqld/mysqld.sock Uptime: 1 hour 22 min 49 sec Threads: 1 Questions: 112138 Slow queries: 1 Opens: 1485 Flush tables: 1 Open tables: 64 Queries per second avg: 22.567.
[email :/home/avi# service mysql stop Stopping MySQL database server: mysqld. [email :/home/avi# service mysql start Starting MySQL database server: mysqld. Checking for corrupt, not cleanly closed and upgrade needing tables..
[email :/home/avi# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 207 Server version: 5.1.72-2 (Debian) Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | a1 | | cloud | | mysql | | phpmyadmin | | playsms | | sisso | | test | | ukolovnik | | wordpress | +--------------------+ 10 rows in set (0.14 sec)
mysql> use cloud; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql>
mysql> show tables; +----------------------------+ | Tables_in_cloud | +----------------------------+ | oc_appconfig | | oc_calendar_calendars | | oc_calendar_objects | | oc_calendar_repeat | | oc_calendar_share_calendar | | oc_calendar_share_event | | oc_contacts_addressbooks | | oc_contacts_cards | | oc_fscache | | oc_gallery_sharing | +----------------------------+ 10 rows in set (0.00 sec)
mysql> describe oc_users; +----------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------+------+-----+---------+-------+ | uid | varchar(64) | NO | PRI | | | | password | varchar(255) | NO | | | | +----------+--------------+------+-----+---------+-------+ 2 rows in set (0.00 sec)
mysql> drop table lookup; Query OK, 0 rows affected (0.00 sec)
mysql> drop database a1; Query OK, 11 rows affected (0.07 sec)
mysql> select * from engines; +------------+---------+----------------------------------------------------------------+--------------+------+------------+ | ENGINE | SUPPORT | COMMENT | TRANSACTIONS | XA | SAVEPOINTS | +------------+---------+----------------------------------------------------------------+--------------+------+------------+ | InnoDB | YES | Supports transactions, row-level locking, and foreign keys | YES | YES | YES | | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO | | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO | | CSV | YES | CSV storage engine | NO | NO | NO | | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO | | FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL | | ARCHIVE | YES | Archive storage engine | NO | NO | NO | | MyISAM | DEFAULT | Default engine as of MySQL 3.23 with great performance | NO | NO | NO | +------------+---------+----------------------------------------------------------------+--------------+------+------------+ 8 rows in set (0.00 sec)
mysql> select uid from oc_users; +-----+ | uid | +-----+ | avi | +-----+ 1 row in set (0.03 sec)
12. mysql> select create_time, engine from xyz where engine="MyIsam"; +---------------------+--------+ | create_time | engine | +---------------------+--------+ | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-12-15 13:43:27 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | | 2013-10-23 14:56:38 | MyISAM | +---------------------+--------+ 132 rows in set (0.29 sec)
mysql> select * from xrt where name = "tecmint" and web_address = “linux-console.net”; +---------------+---------------------+---------------+ | Id | name | web_address | +---------------+---------------------+----------------+ | 13 | tecmint | linux-console.net | +---------------+---------------------+----------------+ | 41 | tecmint | linux-console.net | +---------------+---------------------+----------------+
mysql> select * from xrt where name != ”tecmint” and web_address = ”linux-console.net”; +---------------+---------------------+---------------+ | Id | name | web_address | +---------------+---------------------+----------------+ | 1173 | tecmint | linux-console.net | +---------------+---------------------+----------------+
mysql> select count(*) from Tables; +----------+ | count(*) | +----------+ | 282 | +----------+ 1 row in set (0.01 sec)
ഇപ്പോഴത്തേക്ക് ഇത്രമാത്രം. ഈ 'ലിനക്സ് അഭിമുഖ ചോദ്യം' വിഭാഗത്തെക്കുറിച്ച് നിങ്ങൾക്ക് എന്തു തോന്നുന്നു. ഞങ്ങളുടെ അഭിപ്രായ വിഭാഗത്തിൽ നിങ്ങളുടെ വിലയേറിയ ഫീഡ്uബാക്ക് ഞങ്ങൾക്ക് നൽകാൻ മറക്കരുത്.