Package | system.db |
---|---|
Inheritance | class CDbConnection » CApplicationComponent » CComponent |
Implements | IApplicationComponent |
Since | 1.0 |
Source Code | framework/db/CDbConnection.php |
$connection=new CDbConnection($dsn,$username,$password); $connection->active=true;
$command=$connection->createCommand($sqlStatement); $command->execute(); // a non-query SQL statement execution // or execute an SQL query and fetch the result set $reader=$command->query(); // each $row is an array representing a row of data foreach($reader as $row) ...
$command=$connection->createCommand($sqlStatement); $command->bindParam($name1,$value1); $command->bindParam($name2,$value2); $command->execute();
$transaction=$connection->beginTransaction(); try { $connection->createCommand($sql1)->execute(); $connection->createCommand($sql2)->execute(); //.... other SQL executions $transaction->commit(); } catch(Exception $e) { $transaction->rollback(); }
array( 'components'=>array( 'db'=>array( 'class'=>'CDbConnection', 'connectionString'=>'sqlite:path/to/dbfile', ), ), )
'db'=>array( 'class'=>'CDbConnection', 'driverName'=>'mysql', 'connectionString'=>'odbc:Driver={MySQL};Server=127.0.0.1;Database=test', 'username'=>'', 'password'=>'', ),
Property | Type | Description | Defined By |
---|---|---|---|
active | boolean | Returns whether the DB connection is established. | CDbConnection |
attributes | array | Returns the attributes that are previously explicitly set for the DB connection. | CDbConnection |
autoCommit | boolean | Returns whether creating or updating a DB record will be automatically committed. | CDbConnection |
autoConnect | boolean | whether the database connection should be automatically established the component is being initialized. | CDbConnection |
behaviors | array | the behaviors that should be attached to this component. | CApplicationComponent |
charset | string | the charset used for database connection. | CDbConnection |
clientVersion | string | Returns the version information of the DB driver. | CDbConnection |
columnCase | mixed | Returns the case of the column names | CDbConnection |
commandBuilder | CDbCommandBuilder | Returns the SQL command builder for the current DB connection. | CDbConnection |
connectionStatus | string | Returns the status of the connection. | CDbConnection |
connectionString | string | The Data Source Name, or DSN, contains the information required to connect to the database. | CDbConnection |
currentTransaction | CDbTransaction | Returns the currently active transaction. | CDbConnection |
driverMap | array | mapping between PDO driver and schema class name. | CDbConnection |
driverName | string | Returns the name of the DB driver. | CDbConnection |
emulatePrepare | boolean | whether to turn on prepare emulation. | CDbConnection |
enableParamLogging | boolean | whether to log the values that are bound to a prepare SQL statement. | CDbConnection |
enableProfiling | boolean | whether to enable profiling the SQL statements being executed. | CDbConnection |
initSQLs | array | list of SQL statements that should be executed right after the DB connection is established. | CDbConnection |
isInitialized | boolean | Checks if this application component has been initialized. | CApplicationComponent |
lastInsertID | string | Returns the ID of the last inserted row or sequence value. | CDbConnection |
nullConversion | mixed | Returns how the null and empty strings are converted. | CDbConnection |
password | string | the password for establishing DB connection. | CDbConnection |
pdoClass | string | Custom PDO wrapper class. | CDbConnection |
pdoInstance | PDO | Returns the PDO instance. | CDbConnection |
persistent | boolean | Returns whether the connection is persistent or not. | CDbConnection |
prefetch | boolean | Returns whether the connection performs data prefetching. | CDbConnection |
queryCacheID | string | the ID of the cache application component that is used for query caching. | CDbConnection |
queryCachingCount | integer | the number of SQL statements that need to be cached next. | CDbConnection |
queryCachingDependency | CCacheDependency|ICacheDependency | the dependency that will be used when saving query results into cache. | CDbConnection |
queryCachingDuration | integer | number of seconds that query results can remain valid in cache. | CDbConnection |
schema | CDbSchema | Returns the database schema for the current connection | CDbConnection |
schemaCacheID | string | the ID of the cache application component that is used to cache the table metadata. | CDbConnection |
schemaCachingDuration | integer | number of seconds that table metadata can remain valid in cache. | CDbConnection |
schemaCachingExclude | array | list of tables whose metadata should NOT be cached. | CDbConnection |
serverInfo | string | Returns the information of DBMS server. | CDbConnection |
serverVersion | string | Returns the version information of DBMS server. | CDbConnection |
stats | array | Returns the statistical results of SQL executions. | CDbConnection |
tablePrefix | string | the default prefix for table names. | CDbConnection |
timeout | integer | Returns the timeout settings for the connection. | CDbConnection |
username | string | the username for establishing DB connection. | CDbConnection |
Method | Description | Defined By |
---|---|---|
__call() | Calls the named method which is not a class method. | CComponent |
__construct() | Constructor. | CDbConnection |
__get() | Returns a property value, an event handler list or a behavior based on its name. | CComponent |
__isset() | Checks if a property value is null. | CComponent |
__set() | Sets value of a component property. | CComponent |
__sleep() | Close the connection when serializing. | CDbConnection |
__unset() | Sets a component property to be null. | CComponent |
asa() | Returns the named behavior object. | CComponent |
attachBehavior() | Attaches a behavior to this component. | CComponent |
attachBehaviors() | Attaches a list of behaviors to the component. | CComponent |
attachEventHandler() | Attaches an event handler to an event. | CComponent |
beginTransaction() | Starts a transaction. | CDbConnection |
cache() | Sets the parameters about query caching. | CDbConnection |
canGetProperty() | Determines whether a property can be read. | CComponent |
canSetProperty() | Determines whether a property can be set. | CComponent |
createCommand() | Creates a command for execution. | CDbConnection |
detachBehavior() | Detaches a behavior from the component. | CComponent |
detachBehaviors() | Detaches all behaviors from the component. | CComponent |
detachEventHandler() | Detaches an existing event handler. | CComponent |
disableBehavior() | Disables an attached behavior. | CComponent |
disableBehaviors() | Disables all behaviors attached to this component. | CComponent |
enableBehavior() | Enables an attached behavior. | CComponent |
enableBehaviors() | Enables all behaviors attached to this component. | CComponent |
evaluateExpression() | Evaluates a PHP expression or callback under the context of this component. | CComponent |
getActive() | Returns whether the DB connection is established. | CDbConnection |
getAttribute() | Obtains a specific DB connection attribute information. | CDbConnection |
getAttributes() | Returns the attributes that are previously explicitly set for the DB connection. | CDbConnection |
getAutoCommit() | Returns whether creating or updating a DB record will be automatically committed. | CDbConnection |
getAvailableDrivers() | Returns a list of available PDO drivers. | CDbConnection |
getClientVersion() | Returns the version information of the DB driver. | CDbConnection |
getColumnCase() | Returns the case of the column names | CDbConnection |
getCommandBuilder() | Returns the SQL command builder for the current DB connection. | CDbConnection |
getConnectionStatus() | Returns the status of the connection. | CDbConnection |
getCurrentTransaction() | Returns the currently active transaction. | CDbConnection |
getDriverName() | Returns the name of the DB driver. | CDbConnection |
getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
getIsInitialized() | Checks if this application component has been initialized. | CApplicationComponent |
getLastInsertID() | Returns the ID of the last inserted row or sequence value. | CDbConnection |
getNullConversion() | Returns how the null and empty strings are converted. | CDbConnection |
getPdoInstance() | Returns the PDO instance. | CDbConnection |
getPdoType() | Determines the PDO type for the specified PHP type. | CDbConnection |
getPersistent() | Returns whether the connection is persistent or not. | CDbConnection |
getPrefetch() | Returns whether the connection performs data prefetching. | CDbConnection |
getSchema() | Returns the database schema for the current connection | CDbConnection |
getServerInfo() | Returns the information of DBMS server. | CDbConnection |
getServerVersion() | Returns the version information of DBMS server. | CDbConnection |
getStats() | Returns the statistical results of SQL executions. | CDbConnection |
getTimeout() | Returns the timeout settings for the connection. | CDbConnection |
hasEvent() | Determines whether an event is defined. | CComponent |
hasEventHandler() | Checks whether the named event has attached handlers. | CComponent |
hasProperty() | Determines whether a property is defined. | CComponent |
init() | Initializes the component. | CDbConnection |
quoteColumnName() | Quotes a column name for use in a query. | CDbConnection |
quoteTableName() | Quotes a table name for use in a query. | CDbConnection |
quoteValue() | Quotes a string value for use in a query. | CDbConnection |
quoteValueWithType() | Quotes a value for use in a query using a given type. | CDbConnection |
raiseEvent() | Raises an event. | CComponent |
setActive() | Open or close the DB connection. | CDbConnection |
setAttribute() | Sets an attribute on the database connection. | CDbConnection |
setAttributes() | Sets a set of attributes on the database connection. | CDbConnection |
setAutoCommit() | Sets whether creating or updating a DB record will be automatically committed. | CDbConnection |
setColumnCase() | Sets the case of the column names. | CDbConnection |
setDriverName() | Changes the name of the DB driver. Overrides value extracted from the connectionString, | CDbConnection |
setNullConversion() | Sets how the null and empty strings are converted. | CDbConnection |
setPersistent() | Sets whether the connection is persistent or not. | CDbConnection |
Method | Description | Defined By |
---|---|---|
close() | Closes the currently active DB connection. | CDbConnection |
createPdoInstance() | Creates the PDO instance. | CDbConnection |
initConnection() | Initializes the open db connection. | CDbConnection |
open() | Opens DB connection if it is currently not | CDbConnection |
Returns whether the DB connection is established.
Returns the attributes that are previously explicitly set for the DB connection.
Returns whether creating or updating a DB record will be automatically committed. Some DBMS (such as sqlite) may not support this feature.
whether the database connection should be automatically established the component is being initialized. Defaults to true. Note, this property is only effective when the CDbConnection object is used as an application component.
the charset used for database connection. The property is only used
for MySQL, MariaDB and PostgreSQL databases. Defaults to null, meaning using default charset
as specified by the database.
Note that if you're using GBK or BIG5 then it's highly recommended to
update to PHP 5.3.6+ and to specify charset via DSN like
'mysql:dbname=mydatabase;host=127.0.0.1;charset=GBK;'.
Returns the version information of the DB driver.
Returns the case of the column names
Returns the SQL command builder for the current DB connection.
Returns the status of the connection. Some DBMS (such as sqlite) may not support this feature.
The Data Source Name, or DSN, contains the information required to connect to the database.
Returns the currently active transaction.
mapping between PDO driver and schema class name. A schema class can be specified using path alias.
Returns the name of the DB driver.
whether to turn on prepare emulation. Defaults to false, meaning PDO will use the native prepare support if available. For some databases (such as MySQL), this may need to be set true so that PDO can emulate the prepare support to bypass the buggy native prepare support. Note, this property is only effective for PHP 5.1.3 or above. The default value is null, which will not change the ATTR_EMULATE_PREPARES value of PDO.
whether to log the values that are bound to a prepare SQL statement. Defaults to false. During development, you may consider setting this property to true so that parameter values bound to SQL statements are logged for debugging purpose. You should be aware that logging parameter values could be expensive and have significant impact on the performance of your application.
whether to enable profiling the SQL statements being executed. Defaults to false. This should be mainly enabled and used during development to find out the bottleneck of SQL executions.
list of SQL statements that should be executed right after the DB connection is established.
Returns the ID of the last inserted row or sequence value.
Returns how the null and empty strings are converted.
the password for establishing DB connection. Defaults to empty string.
Custom PDO wrapper class.
Returns the PDO instance.
Returns whether the connection is persistent or not. Some DBMS (such as sqlite) may not support this feature.
Returns whether the connection performs data prefetching.
the ID of the cache application component that is used for query caching. Defaults to 'cache' which refers to the primary cache application component. Set this property to false if you want to disable query caching.
the number of SQL statements that need to be cached next. If this is 0, then even if query caching is enabled, no query will be cached. Note that each time after executing a SQL statement (whether executed on DB server or fetched from query cache), this property will be reduced by 1 until 0.
the dependency that will be used when saving query results into cache.
number of seconds that query results can remain valid in cache.
Use 0 or negative value to indicate not caching query results (the default behavior).
In order to enable query caching, this property must be a positive
integer and queryCacheID must point to a valid cache component ID.
The method cache() is provided as a convenient way of setting this property
and queryCachingDependency on the fly.
Returns the database schema for the current connection
the ID of the cache application component that is used to cache the table metadata. Defaults to 'cache' which refers to the primary cache application component. Set this property to false if you want to disable caching table metadata.
number of seconds that table metadata can remain valid in cache. Use 0 or negative value to indicate not caching schema. If greater than 0 and the primary cache is enabled, the table metadata will be cached.
list of tables whose metadata should NOT be cached. Defaults to empty array.
Returns the information of DBMS server.
Returns the version information of DBMS server.
Returns the statistical results of SQL executions. The results returned include the number of SQL statements executed and the total time spent. In order to use this method, enableProfiling has to be set true.
the default prefix for table names. Defaults to null, meaning no table prefix. By setting this property, any token like '{{tableName}}' in CDbCommand::text will be replaced by 'prefixTableName', where 'prefix' refers to this property value.
Returns the timeout settings for the connection.
the username for establishing DB connection. Defaults to empty string.
public void __construct(string $dsn='', string $username='', string $password='')
| ||
$dsn | string | The Data Source Name, or DSN, contains the information required to connect to the database. |
$username | string | The user name for the DSN string. |
$password | string | The password for the DSN string. |
public function __construct($dsn='',$username='',$password='')
{
$this->connectionString=$dsn;
$this->username=$username;
$this->password=$password;
}
Constructor. Note, the DB connection is not established when this connection instance is created. Set active property to true to establish the connection.
public array __sleep()
| ||
{return} | array |
public function __sleep()
{
$this->close();
return array_keys(get_object_vars($this));
}
Close the connection when serializing.
public CDbTransaction beginTransaction()
| ||
{return} | CDbTransaction | the transaction initiated |
public function beginTransaction()
{
Yii::trace('Starting transaction','system.db.CDbConnection');
$this->setActive(true);
$this->_pdo->beginTransaction();
return $this->_transaction=new CDbTransaction($this);
}
Starts a transaction.
public static cache(integer $duration, CCacheDependency|ICacheDependency $dependency=NULL, integer $queryCount=1)
| ||
$duration | integer | the number of seconds that query results may remain valid in cache. If this is 0, the caching will be disabled. |
$dependency | CCacheDependency|ICacheDependency | the dependency that will be used when saving the query results into cache. |
$queryCount | integer | number of SQL queries that need to be cached after calling this method. Defaults to 1, meaning that the next SQL query will be cached. |
{return} | static | the connection instance itself. |
public function cache($duration, $dependency=null, $queryCount=1)
{
$this->queryCachingDuration=$duration;
$this->queryCachingDependency=$dependency;
$this->queryCachingCount=$queryCount;
return $this;
}
Sets the parameters about query caching. This method can be used to enable or disable query caching. By setting the $duration parameter to be 0, the query caching will be disabled. Otherwise, query results of the new SQL statements executed next will be saved in cache and remain valid for the specified duration. If the same query is executed again, the result may be fetched from cache directly without actually executing the SQL statement.
protected void close()
|
protected function close()
{
Yii::trace('Closing DB connection','system.db.CDbConnection');
$this->_pdo=null;
$this->_active=false;
$this->_schema=null;
}
Closes the currently active DB connection. It does nothing if the connection is already closed.
public CDbCommand createCommand(mixed $query=NULL)
| ||
$query | mixed | the DB query to be executed. This can be either a string representing a SQL statement, or an array representing different fragments of a SQL statement. Please refer to CDbCommand::__construct for more details about how to pass an array as the query. If this parameter is not given, you will have to call query builder methods of CDbCommand to build the DB query. |
{return} | CDbCommand | the DB command |
public function createCommand($query=null)
{
$this->setActive(true);
return new CDbCommand($this,$query);
}
Creates a command for execution.
protected PDO createPdoInstance()
| ||
{return} | PDO | the pdo instance |
protected function createPdoInstance()
{
$pdoClass=$this->pdoClass;
if(($driver=$this->getDriverName())!==null)
{
if($driver==='mssql' || $driver==='dblib')
$pdoClass='CMssqlPdoAdapter';
elseif($driver==='sqlsrv')
$pdoClass='CMssqlSqlsrvPdoAdapter';
}
if(!class_exists($pdoClass))
throw new CDbException(Yii::t('yii','CDbConnection is unable to find PDO class "{className}". Make sure PDO is installed correctly.',
array('{className}'=>$pdoClass)));
@$instance=new $pdoClass($this->connectionString,$this->username,$this->password,$this->_attributes);
if(!$instance)
throw new CDbException(Yii::t('yii','CDbConnection failed to open the DB connection.'));
return $instance;
}
Creates the PDO instance. When some functionalities are missing in the pdo driver, we may use an adapter class to provide them.
public boolean getActive()
| ||
{return} | boolean | whether the DB connection is established |
public function getActive()
{
return $this->_active;
}
Returns whether the DB connection is established.
public mixed getAttribute(integer $name)
| ||
$name | integer | the attribute to be queried |
{return} | mixed | the corresponding attribute information |
public function getAttribute($name)
{
$this->setActive(true);
return $this->_pdo->getAttribute($name);
}
Obtains a specific DB connection attribute information.
public array getAttributes()
| ||
{return} | array | attributes (name=>value) that are previously explicitly set for the DB connection. |
public function getAttributes()
{
return $this->_attributes;
}
Returns the attributes that are previously explicitly set for the DB connection.
public boolean getAutoCommit()
| ||
{return} | boolean | whether creating or updating a DB record will be automatically committed. |
public function getAutoCommit()
{
return $this->getAttribute(PDO::ATTR_AUTOCOMMIT);
}
Returns whether creating or updating a DB record will be automatically committed. Some DBMS (such as sqlite) may not support this feature.
public static array getAvailableDrivers()
| ||
{return} | array | list of available PDO drivers |
public static function getAvailableDrivers()
{
return PDO::getAvailableDrivers();
}
Returns a list of available PDO drivers.
public string getClientVersion()
| ||
{return} | string | the version information of the DB driver |
public function getClientVersion()
{
return $this->getAttribute(PDO::ATTR_CLIENT_VERSION);
}
Returns the version information of the DB driver.
public mixed getColumnCase()
| ||
{return} | mixed | the case of the column names |
public function getColumnCase()
{
return $this->getAttribute(PDO::ATTR_CASE);
}
Returns the case of the column names
public CDbCommandBuilder getCommandBuilder()
| ||
{return} | CDbCommandBuilder | the command builder |
public function getCommandBuilder()
{
return $this->getSchema()->getCommandBuilder();
}
Returns the SQL command builder for the current DB connection.
public string getConnectionStatus()
| ||
{return} | string | the status of the connection |
public function getConnectionStatus()
{
return $this->getAttribute(PDO::ATTR_CONNECTION_STATUS);
}
Returns the status of the connection. Some DBMS (such as sqlite) may not support this feature.
public CDbTransaction getCurrentTransaction()
| ||
{return} | CDbTransaction | the currently active transaction. Null if no active transaction. |
public function getCurrentTransaction()
{
if($this->_transaction!==null)
{
if($this->_transaction->getActive())
return $this->_transaction;
}
return null;
}
Returns the currently active transaction.
public string getDriverName()
| ||
{return} | string | name of the DB driver. |
public function getDriverName()
{
if($this->_driverName!==null)
return $this->_driverName;
elseif(($pos=strpos($this->connectionString,':'))!==false)
return $this->_driverName=strtolower(substr($this->connectionString,0,$pos));
//return $this->getAttribute(PDO::ATTR_DRIVER_NAME);
}
Returns the name of the DB driver.
public string getLastInsertID(string $sequenceName='')
| ||
$sequenceName | string | name of the sequence object (required by some DBMS) |
{return} | string | the row ID of the last row inserted, or the last value retrieved from the sequence object |
public function getLastInsertID($sequenceName='')
{
$this->setActive(true);
return $this->_pdo->lastInsertId($sequenceName);
}
Returns the ID of the last inserted row or sequence value.
public mixed getNullConversion()
| ||
{return} | mixed | how the null and empty strings are converted |
public function getNullConversion()
{
return $this->getAttribute(PDO::ATTR_ORACLE_NULLS);
}
Returns how the null and empty strings are converted.
public PDO getPdoInstance()
| ||
{return} | PDO | the PDO instance, null if the connection is not established yet |
public function getPdoInstance()
{
return $this->_pdo;
}
Returns the PDO instance.
public integer getPdoType(string $type)
| ||
$type | string | The PHP type (obtained by gettype() call). |
{return} | integer | the corresponding PDO type |
public function getPdoType($type)
{
static $map=array
(
'boolean'=>PDO::PARAM_BOOL,
'integer'=>PDO::PARAM_INT,
'string'=>PDO::PARAM_STR,
'resource'=>PDO::PARAM_LOB,
'NULL'=>PDO::PARAM_NULL,
);
return isset($map[$type]) ? $map[$type] : PDO::PARAM_STR;
}
Determines the PDO type for the specified PHP type.
public boolean getPersistent()
| ||
{return} | boolean | whether the connection is persistent or not |
public function getPersistent()
{
return $this->getAttribute(PDO::ATTR_PERSISTENT);
}
Returns whether the connection is persistent or not. Some DBMS (such as sqlite) may not support this feature.
public boolean getPrefetch()
| ||
{return} | boolean | whether the connection performs data prefetching |
public function getPrefetch()
{
return $this->getAttribute(PDO::ATTR_PREFETCH);
}
Returns whether the connection performs data prefetching.
public CDbSchema getSchema()
| ||
{return} | CDbSchema | the database schema for the current connection |
public function getSchema()
{
if($this->_schema!==null)
return $this->_schema;
else
{
$driver=$this->getDriverName();
if(isset($this->driverMap[$driver]))
return $this->_schema=Yii::createComponent($this->driverMap[$driver], $this);
else
throw new CDbException(Yii::t('yii','CDbConnection does not support reading schema for {driver} database.',
array('{driver}'=>$driver)));
}
}
Returns the database schema for the current connection
public string getServerInfo()
| ||
{return} | string | the information of DBMS server |
public function getServerInfo()
{
return $this->getAttribute(PDO::ATTR_SERVER_INFO);
}
Returns the information of DBMS server.
public string getServerVersion()
| ||
{return} | string | the version information of DBMS server |
public function getServerVersion()
{
return $this->getAttribute(PDO::ATTR_SERVER_VERSION);
}
Returns the version information of DBMS server.
public array getStats()
| ||
{return} | array | the first element indicates the number of SQL statements executed, and the second element the total time spent in SQL execution. |
public function getStats()
{
$logger=Yii::getLogger();
$timings=$logger->getProfilingResults(null,'system.db.CDbCommand.query');
$count=count($timings);
$time=array_sum($timings);
$timings=$logger->getProfilingResults(null,'system.db.CDbCommand.execute');
$count+=count($timings);
$time+=array_sum($timings);
return array($count,$time);
}
Returns the statistical results of SQL executions. The results returned include the number of SQL statements executed and the total time spent. In order to use this method, enableProfiling has to be set true.
public integer getTimeout()
| ||
{return} | integer | timeout settings for the connection |
public function getTimeout()
{
return $this->getAttribute(PDO::ATTR_TIMEOUT);
}
Returns the timeout settings for the connection.
public void init()
|
public function init()
{
parent::init();
if($this->autoConnect)
$this->setActive(true);
}
Initializes the component. This method is required by IApplicationComponent and is invoked by application when the CDbConnection is used as an application component. If you override this method, make sure to call the parent implementation so that the component can be marked as initialized.
protected void initConnection(PDO $pdo)
| ||
$pdo | PDO | the PDO instance |
protected function initConnection($pdo)
{
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
if($this->emulatePrepare!==null && constant('PDO::ATTR_EMULATE_PREPARES'))
$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES,$this->emulatePrepare);
if($this->charset!==null)
{
$driver=strtolower($pdo->getAttribute(PDO::ATTR_DRIVER_NAME));
if(in_array($driver,array('pgsql','mysql','mysqli')))
$pdo->exec('SET NAMES '.$pdo->quote($this->charset));
}
if($this->initSQLs!==null)
{
foreach($this->initSQLs as $sql)
$pdo->exec($sql);
}
}
Initializes the open db connection. This method is invoked right after the db connection is established. The default implementation is to set the charset for MySQL, MariaDB and PostgreSQL database connections.
protected void open()
|
protected function open()
{
if($this->_pdo===null)
{
if(empty($this->connectionString))
throw new CDbException('CDbConnection.connectionString cannot be empty.');
try
{
Yii::trace('Opening DB connection','system.db.CDbConnection');
$this->_pdo=$this->createPdoInstance();
$this->initConnection($this->_pdo);
$this->_active=true;
}
catch(PDOException $e)
{
if(YII_DEBUG)
{
throw new CDbException('CDbConnection failed to open the DB connection: '.
$e->getMessage(),(int)$e->getCode(),$e->errorInfo);
}
else
{
Yii::log($e->getMessage(),CLogger::LEVEL_ERROR,'exception.CDbException');
throw new CDbException('CDbConnection failed to open the DB connection.',(int)$e->getCode(),$e->errorInfo);
}
}
}
}
Opens DB connection if it is currently not
public string quoteColumnName(string $name)
| ||
$name | string | column name |
{return} | string | the properly quoted column name |
public function quoteColumnName($name)
{
return $this->getSchema()->quoteColumnName($name);
}
Quotes a column name for use in a query. If the column name contains prefix, the prefix will also be properly quoted.
public string quoteTableName(string $name)
| ||
$name | string | table name |
{return} | string | the properly quoted table name |
public function quoteTableName($name)
{
return $this->getSchema()->quoteTableName($name);
}
Quotes a table name for use in a query. If the table name contains schema prefix, the prefix will also be properly quoted.
public string quoteValue(string $str)
| ||
$str | string | string to be quoted |
{return} | string | the properly quoted string |
public function quoteValue($str)
{
if(is_int($str) || is_float($str))
return $str;
$this->setActive(true);
if(($value=$this->_pdo->quote($str))!==false)
return $value;
else // the driver doesn't support quote (e.g. oci)
return "'" . addcslashes(str_replace("'", "''", $str), "\000\n\r\\\032") . "'";
}
Quotes a string value for use in a query.
public string quoteValueWithType(mixed $value, integer $type)
| ||
$value | mixed | the value to be quoted. |
$type | integer | The type to be used for quoting. This should be one of the `PDO::PARAM_*` constants described in PDO documentation. This parameter will be passed to the `PDO::quote()` function. |
{return} | string | the properly quoted string. |
public function quoteValueWithType($value, $type)
{
$this->setActive(true);
if(($quoted=$this->_pdo->quote($value, $type))!==false)
return $quoted;
else // the driver doesn't support quote (e.g. oci)
return "'" . addcslashes(str_replace("'", "''", $value), "\000\n\r\\\032") . "'";
}
Quotes a value for use in a query using a given type.
public void setActive(boolean $value)
| ||
$value | boolean | whether to open or close DB connection |
public function setActive($value)
{
if($value!=$this->_active)
{
if($value)
$this->open();
else
$this->close();
}
}
Open or close the DB connection.
public void setAttribute(integer $name, mixed $value)
| ||
$name | integer | the attribute to be set |
$value | mixed | the attribute value |
public function setAttribute($name,$value)
{
if($this->_pdo instanceof PDO)
$this->_pdo->setAttribute($name,$value);
else
$this->_attributes[$name]=$value;
}
Sets an attribute on the database connection.
public void setAttributes(array $values)
| ||
$values | array | attributes (name=>value) to be set. |
public function setAttributes($values)
{
foreach($values as $name=>$value)
$this->_attributes[$name]=$value;
}
Sets a set of attributes on the database connection.
public void setAutoCommit(boolean $value)
| ||
$value | boolean | whether creating or updating a DB record will be automatically committed. |
public function setAutoCommit($value)
{
$this->setAttribute(PDO::ATTR_AUTOCOMMIT,$value);
}
Sets whether creating or updating a DB record will be automatically committed. Some DBMS (such as sqlite) may not support this feature.
public void setColumnCase(mixed $value)
| ||
$value | mixed | the case of the column names |
public function setColumnCase($value)
{
$this->setAttribute(PDO::ATTR_CASE,$value);
}
Sets the case of the column names.
public void setDriverName(string $driverName)
| ||
$driverName | string | to be set. Valid values are the keys from the driverMap property. |
public function setDriverName($driverName)
{
$this->_driverName=strtolower($driverName);
}
Changes the name of the DB driver. Overrides value extracted from the connectionString, which is behavior by default.
public void setNullConversion(mixed $value)
| ||
$value | mixed | how the null and empty strings are converted |
public function setNullConversion($value)
{
$this->setAttribute(PDO::ATTR_ORACLE_NULLS,$value);
}
Sets how the null and empty strings are converted.
public void setPersistent(boolean $value)
| ||
$value | boolean | whether the connection is persistent or not |
public function setPersistent($value)
{
return $this->setAttribute(PDO::ATTR_PERSISTENT,$value);
}
Sets whether the connection is persistent or not. Some DBMS (such as sqlite) may not support this feature.
Changing the database at runtime
If you're using multiple databases for a single application with multiple instances then you will probably reach a point where you need to point the standard Yii::app()->db to a different database (i.e. applying migrations)
This is fairly easy to accomplish and here's how I did it.
The db component configuration key points
'connectionString' => 'mysql:host=localhost;dbname=%s', 'autoConnect' => false,
Load the connection string from the console.php configuration file
$config = require(Yii::app()->getBasePath() . '/config/console.php'); $connectionString = $config['components']['db']['connectionString'];
Switching to another db
// assume a foreach loop where $dbName holds the next database name on every iteration $db = Yii::app()->db; $db->active = false; $db->connectionString = sprintf($connectionString, $dbName); $db->active = true;
In my case as mentioned I needed it for the CLI interface. I extend ConsoleCommand and override the run method where I iterate through all the schemas on the server applying my migrations and other command line commands
Hope this helps a bit
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