Difference between revisions of "SQL"
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To fix a crashed table just use '''repair TABLENAME''' from the MySQL command line, or to automatically scan all tables and fix them run the following from the shell. | To fix a crashed table just use '''repair TABLENAME''' from the MySQL command line, or to automatically scan all tables and fix them run the following from the shell. | ||
<source lang="bash"> | <source lang="bash"> | ||
| − | mysqlcheck --auto-repair DBNAME -u USER -p | + | mysqlcheck -vvvv --auto-repair DBNAME -u USER -p |
</source> | </source> | ||
== Database procedures == | == Database procedures == | ||
| + | *[[MediaWiki SQL queries]] | ||
*[[Reset MySQL root password]] | *[[Reset MySQL root password]] | ||
*[[Renaming MySQL tables and databases]] | *[[Renaming MySQL tables and databases]] | ||
| Line 26: | Line 27: | ||
*[[Manually backup a wiki]] | *[[Manually backup a wiki]] | ||
*[[Add a wiki database]] | *[[Add a wiki database]] | ||
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| + | == Character sets == | ||
| + | *[http://tlug.dnho.net/?q=node/276 Convert a MySQL DB from latin1 to UTF8] | ||
| + | *[https://mathiasbynens.be/notes/mysql-utf8mb4 MySQL and utf8mb4] | ||
== See also == | == See also == | ||
*[[MariaDB]] | *[[MariaDB]] | ||
*[https://stackoverflow.com/questions/5836623/getting-lock-wait-timeout-exceeded-try-restarting-transaction-even-though-im Good thread on table lock problems and solutions] | *[https://stackoverflow.com/questions/5836623/getting-lock-wait-timeout-exceeded-try-restarting-transaction-even-though-im Good thread on table lock problems and solutions] | ||
| − | |||
*[http://www.sql-tutorial.com/ SQL Tutorial] ''- A nice tutorial on SQL'' | *[http://www.sql-tutorial.com/ SQL Tutorial] ''- A nice tutorial on SQL'' | ||
*[http://dev.mysql.com/doc/index.html Official MySQL Documentation] | *[http://dev.mysql.com/doc/index.html Official MySQL Documentation] | ||
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*[https://www.databasestar.com/sql-joins/ Introduction to SQL joins] | *[https://www.databasestar.com/sql-joins/ Introduction to SQL joins] | ||
*[http://www.x7media.com/resources/SQL_Differences_Between_Microsoft_SQL_Server_and_MySQL.asp List of common differences between MySQL and MSSQL] | *[http://www.x7media.com/resources/SQL_Differences_Between_Microsoft_SQL_Server_and_MySQL.asp List of common differences between MySQL and MSSQL] | ||
| + | *[https://www.heidisql.com/screenshots.php HeidiSQL] ''- see and edit data and structures from MariaDB, MySQL, Microsoft SQL or PostgreSQL databases'' | ||
| + | *[https://edgedb.com/blog/we-can-do-better-than-sql/ We can do better than SQL] | ||
Latest revision as of 00:35, 23 September 2019
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SQL (Structured Query Language) is a computer language used to create, retrieve, update and delete data from relational database management systems. SQL has been standardised by both ANSI and ISO.
SQL is commonly spoken either as the names of the letters ess-cue-el, or like the word sequel. The official pronunciation of SQL according to ANSI is ess-cue-el. However, each of the major database products (or projects) containing the letters SQL has its own convention: MySQL is officially and commonly pronounced "My Ess Cue El"; PostgreSQL is expediently pronounced postgres (being the name of the predecessor to PostgreSQL); and Microsoft SQL Server is commonly spoken as Microsoft-sequel-server. See MediaWikiLite for information about SQLite support in MediaWiki, or MSSQL for information about Microsoft SQL Server support. We're now using MariaDB for our SQL server which is a drop-in replacement for MySQL but is fully open source and more efficient too.
Contents
Backup & restore
See backup for details about this as it's doesn't outside the SQL environment so doesn't belong in this article. But don't forget to set the default character set to the same as the dump used when you import the data!
To restore only a single database from a full dump use the following:
mysql -D DBNAME -o DBNAME < dump.sqlFixing crashed tables
To fix a crashed table just use repair TABLENAME from the MySQL command line, or to automatically scan all tables and fix them run the following from the shell.
mysqlcheck -vvvv --auto-repair DBNAME -u USER -pDatabase procedures
- MediaWiki SQL queries
- Reset MySQL root password
- Renaming MySQL tables and databases
- Rename a MediaWiki database
- Reset a wiki user password
- Set a user preference
- Manually backup a wiki
- Add a wiki database
Character sets
See also
- MariaDB
- Good thread on table lock problems and solutions
- SQL Tutorial - A nice tutorial on SQL
- Official MySQL Documentation
- W3C SQL Tutorial (QuickRef)
- Introduction to SQL joins
- List of common differences between MySQL and MSSQL
- HeidiSQL - see and edit data and structures from MariaDB, MySQL, Microsoft SQL or PostgreSQL databases
- We can do better than SQL
