Class Connection

Represents a connection with a database server.

Properties summary

$_config protected

array

Contains the configuration params for this connection.
$_driver protected

\Cake\Database\DriverInterface

Driver object, responsible for creating the real connection and provide specific SQL dialect.
$_logQueries protected

bool

Whether to log queries generated during this connection.
$_logger protected

\Psr\Log\LoggerInterface|null

Logger object instance.
$_schemaCollection protected

\Cake\Database\Schema\CollectionInterface|null

The schema collection object
$_transactionLevel protected

int

Contains how many nested transactions have been started.
$_transactionStarted protected

bool

Whether a transaction is active in this connection.
$_useSavePoints protected

bool

Whether this connection can and should use savepoints for nested transactions.
$cacher protected

\Psr\SimpleCache\CacheInterface|null

Cacher object instance.
$nestedTransactionRollbackException protected

\Cake\Database\Exception\NestedTransactionRollbackException|null

NestedTransactionRollbackException object instance, will be stored if the rollback method is called in some nested transaction.

Method Summary

__construct() public

Constructor.
__debugInfo() public

Returns an array that can be used to describe the internal state of this object.
__destruct() public

Destructor
_newLogger() protected

Returns a new statement object that will log the activity for the passed original statement instance.
begin() public

Starts a new transaction.
cacheMetadata() public

Enables or disables metadata caching for this connection
cast() public

Converts a give value to a suitable database value based on type and return relevant internal statement type
commit() public

Commits current transaction.
compileQuery() public

Compiles a Query object into a SQL string according to the dialect for this connection's driver
config() public

Get the configuration data used to create the connection.
configName() public

Get the configuration name for this connection.
connect() public

Connects to the configured database.
createSavePoint() public

Creates a new save point for nested transactions.
delete() public

Executes a DELETE statement on the specified table.
disableConstraints() public

Run an operation with constraints disabled.
disableForeignKeys() public

Run driver specific SQL to disable foreign key checks.
disableQueryLogging() public

Disable query logging
disableSavePoints() public

Disables the usage of savepoints.
disconnect() public

Disconnects from database server.
enableForeignKeys() public

Run driver specific SQL to enable foreign key checks.
enableQueryLogging() public

Enable/disable query logging
enableSavePoints() public

Enables/disables the usage of savepoints, enables only if driver the allows it.
execute() public

Executes a query using $params for interpolating values and $types as a hint for each those params.
getCacher() public

Get a cacher.
getDisconnectRetry() public

Get the retry wrapper object that is allows recovery from server disconnects while performing certain database actions, such as executing a query.
getDriver() public

Gets the driver instance.
getLogger() public

Gets the logger object
getSchemaCollection() public

Gets a Schema\Collection object for this connection.
inTransaction() public

Checks if a transaction is running.
insert() public

Executes an INSERT query on the specified table.
isConnected() public

Returns whether connection to database server was already established.
isQueryLoggingEnabled() public

Check if query logging is enabled.
isSavePointsEnabled() public

Returns whether this connection is using savepoints for nested transactions
log() public

Logs a Query string using the configured logger object.
matchTypes() public

Matches columns to corresponding types
newQuery() public

Create a new Query instance for this connection.
prepare() public

Prepares a SQL statement to be executed.
query() public

Executes a SQL statement and returns the Statement object as result.
quote() public

Quotes value to be used safely in database query.
quoteIdentifier() public

Quotes a database identifier (a column name, table name, etc..) to be used safely in queries without the risk of using reserved words.
releaseSavePoint() public

Releases a save point by its name.
rollback() public

Rollback current transaction.
rollbackSavepoint() public

Rollback a save point by its name.
run() public

Executes the provided query after compiling it for the specific driver dialect and returns the executed Statement object.
setCacher() public

Set a cacher.
setDriver() public

Sets the driver instance. If a string is passed it will be treated as a class name and will be instantiated.
setLogger() public

Sets a logger
setSchemaCollection() public

Sets a Schema\Collection object for this connection.
supportsDynamicConstraints() public

Returns whether the driver supports adding or dropping constraints to already created tables.
supportsQuoting() public

Checks if the driver supports quoting.
transactional() public

Executes a callable function inside a transaction, if any exception occurs while executing the passed callable, the transaction will be rolled back If the result of the callable function is false, the transaction will also be rolled back. Otherwise the transaction is committed after executing the callback.
update() public

Executes an UPDATE statement on the specified table.
wasNestedTransactionRolledback() protected

Returns whether some nested transaction has been already rolled back.

Method Detail

__construct() public

__construct(array $config)

Constructor.

Available options:

driver Sort name or FCQN for driver.
log Boolean indicating whether to use query logging.
name Connection name.
cacheMetaData Boolean indicating whether metadata (datasource schemas) should be cached. If set to a string it will be used as the name of cache config to use.
cacheKeyPrefix Custom prefix to use when generation cache keys. Defaults to connection name.

Parameters

array $config: Configuration array.

__debugInfo() public

__debugInfo()

Returns an array that can be used to describe the internal state of this object.

Returns

array

__destruct() public

__destruct()

Destructor

Disconnects the driver to release the connection.

_newLogger() protected

_newLogger(\Cake\Database\StatementInterface $statement)

Returns a new statement object that will log the activity for the passed original statement instance.

Parameters

\Cake\Database\StatementInterface $statement: the instance to be decorated

Returns

\Cake\Database\Log\LoggingStatement

begin() public

begin()

Starts a new transaction.

cacheMetadata() public

cacheMetadata(mixed $cache)

Enables or disables metadata caching for this connection

Changing this setting will not modify existing schema collections objects.

Parameters

bool|string $cache: Either boolean false to disable metadata caching, or true to use _cake_model_ or the name of the cache config to use.

cast() public

cast(mixed $value, mixed $type)

Converts a give value to a suitable database value based on type and return relevant internal statement type

Parameters

mixed $value: The value to cast
\Cake\Database\TypeInterface|string|int $type optional: The type name or type instance to use.

Returns

array

list containing converted value and internal type

commit() public

commit()

Commits current transaction.

Returns

bool

true on success, false otherwise

compileQuery() public

compileQuery(\Cake\Database\Query $query, \Cake\Database\ValueBinder $generator)

Compiles a Query object into a SQL string according to the dialect for this connection's driver

Parameters

\Cake\Database\Query $query: The query to be compiled
\Cake\Database\ValueBinder $generator: The placeholder generator to use

Returns

string

config() public

config()

Get the configuration data used to create the connection.

Returns

array

configName() public

configName()

Get the configuration name for this connection.

Returns

string

connect() public

connect()

Connects to the configured database.

Returns

bool

true, if the connection was already established or the attempt was successful.

Throws

Cake\Database\Exception\MissingConnectionException
If database connection could not be established.

createSavePoint() public

createSavePoint(mixed $name)

Creates a new save point for nested transactions.

Parameters

string|int $name: The save point name.

delete() public

delete(string $table, array $conditions, array $types)

Executes a DELETE statement on the specified table.

Parameters

string $table: the table to delete rows from
array $conditions optional: conditions to be set for delete statement
array $types optional: list of associative array containing the types to be used for casting

Returns

\Cake\Database\StatementInterface

disableConstraints() public

disableConstraints(callable $operation)

Run an operation with constraints disabled.

Constraints should be re-enabled after the callback succeeds/fails.

Example:

$connection->disableConstraints(function ($connection) {
  $connection->newQuery()->delete('users')->execute();
});

Parameters

callable $operation: The callback to execute within a transaction.

Returns

mixed

The return value of the callback.

Throws

Exception
Will re-throw any exception raised in $callback after rolling back the transaction.

disableForeignKeys() public

disableForeignKeys()

Run driver specific SQL to disable foreign key checks.

disableQueryLogging() public

disableQueryLogging()

Disable query logging

Returns

$this

disableSavePoints() public

disableSavePoints()

Disables the usage of savepoints.

Returns

$this

disconnect() public

disconnect()

Disconnects from database server.

enableForeignKeys() public

enableForeignKeys()

Run driver specific SQL to enable foreign key checks.

enableQueryLogging() public

enableQueryLogging(bool $value)

Enable/disable query logging

Parameters

bool $value optional: Enable/disable query logging

Returns

$this

enableSavePoints() public

enableSavePoints(bool $enable)

Enables/disables the usage of savepoints, enables only if driver the allows it.

If you are trying to enable this feature, make sure you check the return value of this function to verify it was enabled successfully.

Example:

$connection->enableSavePoints(true) Returns true if drivers supports save points, false otherwise $connection->enableSavePoints(false) Disables usage of savepoints and returns false

Parameters

bool $enable optional: Whether or not save points should be used.

Returns

$this

execute() public

execute(string $query, array $params, array $types)

Executes a query using $params for interpolating values and $types as a hint for each those params.

Parameters

string $query: SQL to be executed and interpolated with $params
array $params optional: list or associative array of params to be interpolated in $query as values
array $types optional: list or associative array of types to be used for casting values in query

Returns

\Cake\Database\StatementInterface

executed statement

getCacher() public

getCacher()

Get a cacher.

Returns

\Psr\SimpleCache\CacheInterface

$cacher Cacher object

getDisconnectRetry() public

getDisconnectRetry()

Get the retry wrapper object that is allows recovery from server disconnects while performing certain database actions, such as executing a query.

Returns

\Cake\Core\Retry\CommandRetry

The retry wrapper

getDriver() public

getDriver()

Gets the driver instance.

Returns

\Cake\Database\DriverInterface

getLogger() public

getLogger()

Gets the logger object

Returns

\Psr\Log\LoggerInterface

logger instance

getSchemaCollection() public

getSchemaCollection()

Gets a Schema\Collection object for this connection.

Returns

\Cake\Database\Schema\CollectionInterface

inTransaction() public

inTransaction()

Checks if a transaction is running.

Returns

bool

True if a transaction is running else false.

insert() public

insert(string $table, array $data, array $types)

Executes an INSERT query on the specified table.

Parameters

string $table: the table to insert values in
array $data: values to be inserted
array $types optional: list of associative array containing the types to be used for casting

Returns

\Cake\Database\StatementInterface

isConnected() public

isConnected()

Returns whether connection to database server was already established.

Returns

bool

isQueryLoggingEnabled() public

isQueryLoggingEnabled()

Check if query logging is enabled.

Returns

bool

isSavePointsEnabled() public

isSavePointsEnabled()

Returns whether this connection is using savepoints for nested transactions

Returns

bool

true if enabled, false otherwise

log() public

log(string $sql)

Logs a Query string using the configured logger object.

Parameters

string $sql: string to be logged

matchTypes() public

matchTypes(array $columns, array $types)

Matches columns to corresponding types

Both $columns and $types should either be numeric based or string key based at the same time.

Parameters

array $columns: list or associative array of columns and parameters to be bound with types
array $types: list or associative array of types

Returns

array

newQuery() public

newQuery()

Create a new Query instance for this connection.

Returns

\Cake\Database\Query

prepare() public

prepare(mixed $sql)

Prepares a SQL statement to be executed.

Parameters

string|\Cake\Database\Query $sql: The SQL to convert into a prepared statement.

Returns

\Cake\Database\StatementInterface

query() public

query(string $sql)

Executes a SQL statement and returns the Statement object as result.

Parameters

string $sql: The SQL query to execute.

Returns

\Cake\Database\StatementInterface

quote() public

quote(mixed $value, mixed $type)

Quotes value to be used safely in database query.

Parameters

mixed $value: The value to quote.
string|int|\Cake\Database\TypeInterface $type optional: Type to be used for determining kind of quoting to perform

Returns

string

Quoted value

quoteIdentifier() public

quoteIdentifier(string $identifier)

Quotes a database identifier (a column name, table name, etc..) to be used safely in queries without the risk of using reserved words.

Parameters

string $identifier: The identifier to quote.

Returns

string

releaseSavePoint() public

releaseSavePoint(mixed $name)

Releases a save point by its name.

Parameters

string|int $name: The save point name.

rollback() public

rollback(?bool $toBeginning)

Rollback current transaction.

Parameters

bool|null $toBeginning optional: Whether or not the transaction should be rolled back to the beginning of it. Defaults to false if using savepoints, or true if not.

Returns

bool

rollbackSavepoint() public

rollbackSavepoint(mixed $name)

Rollback a save point by its name.

Parameters

string|int $name: The save point name.

run() public

run(\Cake\Database\Query $query)

Executes the provided query after compiling it for the specific driver dialect and returns the executed Statement object.

Parameters

\Cake\Database\Query $query: The query to be executed

Returns

\Cake\Database\StatementInterface

executed statement

setCacher() public

setCacher(\Psr\SimpleCache\CacheInterface $cacher)

Set a cacher.

Parameters

\Psr\SimpleCache\CacheInterface $cacher: Cacher object

Returns

$this

setDriver() public

setDriver(mixed $driver, mixed $config)

Sets the driver instance. If a string is passed it will be treated as a class name and will be instantiated.

Parameters

\Cake\Database\DriverInterface|string $driver: The driver instance to use.
array $config optional: Config for a new driver.

Returns

$this

Throws

Cake\Database\Exception\MissingDriverException
When a driver class is missing.
Cake\Database\Exception\MissingExtensionException
When a driver's PHP extension is missing.

setLogger() public

setLogger(\Psr\Log\LoggerInterface $logger)

Sets a logger

Parameters

\Psr\Log\LoggerInterface $logger: Logger object

Returns

$this

setSchemaCollection() public

setSchemaCollection(\Cake\Database\Schema\CollectionInterface $collection)

Sets a Schema\Collection object for this connection.

Parameters

\Cake\Database\Schema\CollectionInterface $collection: The schema collection object

Returns

$this

supportsDynamicConstraints() public

supportsDynamicConstraints()

Returns whether the driver supports adding or dropping constraints to already created tables.

Returns

bool

true if driver supports dynamic constraints

supportsQuoting() public

supportsQuoting()

Checks if the driver supports quoting.

Returns

bool

transactional() public

transactional(callable $transaction)

Executes a callable function inside a transaction, if any exception occurs while executing the passed callable, the transaction will be rolled back If the result of the callable function is false, the transaction will also be rolled back. Otherwise the transaction is committed after executing the callback.

The callback will receive the connection instance as its first argument.

Example:

$connection->transactional(function ($connection) {
  $connection->newQuery()->delete('users')->execute();
});

Parameters

callable $transaction: The callback to execute within a transaction.

Returns

mixed

The return value of the callback.

Throws

Exception
Will re-throw any exception raised in $callback after rolling back the transaction.

update() public

update(string $table, array $data, array $conditions, array $types)

Executes an UPDATE statement on the specified table.

Parameters

string $table: the table to update rows from
array $data: values to be updated
array $conditions optional: conditions to be set for update statement
array $types optional: list of associative array containing the types to be used for casting

Returns

\Cake\Database\StatementInterface

wasNestedTransactionRolledback() protected

wasNestedTransactionRolledback()

Returns whether some nested transaction has been already rolled back.

Returns

bool

Property Detail

`$_config` protected

Contains the configuration params for this connection.

Type

array

`$_driver` protected

Driver object, responsible for creating the real connection and provide specific SQL dialect.

Type

\Cake\Database\DriverInterface

`$_logQueries` protected

Whether to log queries generated during this connection.

Type

bool

`$_logger` protected

Logger object instance.

Type

\Psr\Log\LoggerInterface|null

`$_schemaCollection` protected

The schema collection object

Type

\Cake\Database\Schema\CollectionInterface|null

`$_transactionLevel` protected

Contains how many nested transactions have been started.

Type

int

`$_transactionStarted` protected

Whether a transaction is active in this connection.

Type

bool

`$_useSavePoints` protected

Whether this connection can and should use savepoints for nested transactions.

Type

bool

`$cacher` protected

Cacher object instance.

Type

\Psr\SimpleCache\CacheInterface|null

`$nestedTransactionRollbackException` protected

NestedTransactionRollbackException object instance, will be stored if the rollback method is called in some nested transaction.

Type

\Cake\Database\Exception\NestedTransactionRollbackException|null

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https://api.cakephp.org/4.0/class-Cake.Database.Connection.html