DbConnect: Difference between revisions
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This function opens a connection to a database and returns an element that can be used with [[dbQuery]]. To disconnect use [[destroyElement]]. | This function opens a connection to a database and returns an element that can be used with [[dbQuery]]. To disconnect use [[destroyElement]]. | ||
Connecting and disconnecting many times can have a performance impact on the server. For optimal performance it is recommended that you use dbConnect once when the resource starts. (The connection will be auto-disconnected when the resource stops) | |||
==Syntax== | ==Syntax== | ||
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This example opens a connection to a SQLite database file in the current resource | This example opens a connection to a SQLite database file in the current resource | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "sqlite", "file.db" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
This example opens a connection to a SQLite database file in another resource | This example opens a connection to a SQLite database file in another resource | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "sqlite", ":resname/file.db" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
This example opens a connection to a SQLite database file in the global databases directory | This example opens a connection to a SQLite database file in the global databases directory | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "sqlite", ":/file.db" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
This example opens a connection to a SQLite database file in a sub directory of the global databases directory | This example opens a connection to a SQLite database file in a sub directory of the global databases directory | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "sqlite", ":/example/sub/dir/file.db" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
This example opens a connection to a MySQL database called 'frank' at server ip 1.2.3.4 and allows the connection to be shared. Note that changing the database or other connection dependent settings affect all connections that are shared. | This example opens a connection to a MySQL database called 'frank' at server ip 1.2.3.4 and allows the connection to be shared. Note that changing the database or other connection dependent settings affect all connections that are shared. | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "mysql", "dbname=frank;host=1.2.3.4", "username", "password", "share=1" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
This example opens a connection to a SQLite database is disallows sharing of the connection | This example opens a connection to a SQLite database is disallows sharing of the connection | ||
<syntaxhighlight lang="lua"> | <syntaxhighlight lang="lua"> | ||
test_db = dbConnect( "sqlite", ":file.db", "", "", "share=0" ) | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Revision as of 22:26, 29 October 2011
Available only in MTA SA 1.1.1 r3328 and onwards This function opens a connection to a database and returns an element that can be used with dbQuery. To disconnect use destroyElement.
Connecting and disconnecting many times can have a performance impact on the server. For optimal performance it is recommended that you use dbConnect once when the resource starts. (The connection will be auto-disconnected when the resource stops)
Syntax
element dbConnect ( string databaseType, string host [, string username, string password, string options ] )
Required Arguments
- databaseType: The type of database. This can be either sqlite or mysql
- host: The target to connect to. The format of this depends on the database type.
- For SQLite it is a filepath to a SQLite database file. If the filepath starts with ":/" then the server's global databases directory is used.
- For MySQL it is a list of key=value pairs separated by semicolons. Supported keys are:
- dbname: Name of the database to use e.g. dbname=test
- host: Host address e.g. host=127.0.0.1
- port: Host port e.g. port=1234 (optional, defaults to standard MySQL port if not used)
- unix_socket: Unix socket or named pipe to use (optional, thankgoodness)
Optional Arguments
- username: Usually required for MySQL, ignored by SQLite
- password: Usually required for MySQL, ignored by SQLite
- options : List of key=value pairs separated by semicolons. Supported keys are:
- share which can be set to 0 or 1. When set to 1, the connection is shared and will be used by other calls to dbConnect with the same host string. This is usually a good thing for SQLite connections, but not so good for MySQL unless care is taken. Default value for SQLite is "share=1". Default value for MySQL is "share=0"
Returns
Returns a database connection element unless there are problems, in which case it return false.
Example
This example opens a connection to a SQLite database file in the current resource
test_db = dbConnect( "sqlite", "file.db" )
This example opens a connection to a SQLite database file in another resource
test_db = dbConnect( "sqlite", ":resname/file.db" )
This example opens a connection to a SQLite database file in the global databases directory
test_db = dbConnect( "sqlite", ":/file.db" )
This example opens a connection to a SQLite database file in a sub directory of the global databases directory
test_db = dbConnect( "sqlite", ":/example/sub/dir/file.db" )
This example opens a connection to a MySQL database called 'frank' at server ip 1.2.3.4 and allows the connection to be shared. Note that changing the database or other connection dependent settings affect all connections that are shared.
test_db = dbConnect( "mysql", "dbname=frank;host=1.2.3.4", "username", "password", "share=1" )
This example opens a connection to a SQLite database is disallows sharing of the connection
test_db = dbConnect( "sqlite", ":file.db", "", "", "share=0" )
Requirements
This template will be deleted.
See Also