Class Comparison
A Comparison is a type of query expression that represents an operation involving a field an operator and a value. In its most common form the string representation of a comparison is field = value
- Cake\Database\Expression\Comparison implements Cake\Database\ExpressionInterface, Cake\Database\Expression\FieldInterface uses Cake\Database\Type\ExpressionTypeCasterTrait , Cake\Database\Expression\FieldTrait
Direct Subclasses
Properties summary
-
$_isMultiple
protectedboolean
-
$_operator
protectedstring
-
$_type
protectedstring|array
-
$_value
protectedmixed
-
$_valueExpressions
protectedA cached list of ExpressionInterface objects that were found in the value for this expression.
Inherited Properties
Method Summary
-
__clone() publicCreate a deep clone.
-
__construct() publicConstructor
-
_bindValue() protectedRegisters a value in the placeholder generator and returns the generated placeholder
-
_collectExpressions() protected
Returns an array with the original $values in the first position and all ExpressionInterface objects that could be found in the second position.
-
_flattenValue() protected
Converts a traversable value into a set of placeholders generated by $generator and separated by
,
-
_stringExpression() protected
Returns a template and a placeholder for the value after registering it with the placeholder $generator
-
getOperator() publicReturns the operator used for comparison
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getValue() publicReturns the value used for comparison
-
setOperator() publicSets the operator to use for the comparison
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setValue() publicSets the value
-
sql() publicConvert the expression into a SQL fragment.
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traverse() public
Iterates over each part of the expression recursively for every level of the expressions tree and executes the $visitor callable passing as first parameter the instance of the expression currently being iterated.
Method Detail
__clone()source public
__clone( )
Create a deep clone.
Clones the field and value if they are expression objects.
__construct()source public
__construct( string|Cake\Database\ExpressionInterface $field , mixed $value , string $type , string $operator )
Constructor
Parameters
-
string|
Cake\Database\ExpressionInterface
$field
- the field name to compare to a value
-
mixed
$value
- The value to be used in comparison
-
string
$type
- the type name used to cast the value
-
string
$operator
- the operator used for comparing field and value
_bindValue()source protected
_bindValue( mixed $value , Cake\Database\ValueBinder $generator , string $type )
Registers a value in the placeholder generator and returns the generated placeholder
Parameters
-
mixed
$value
- The value to bind
-
Cake\Database\ValueBinder
$generator
- The value binder to use
-
string
$type
- The type of $value
Returns
stringgenerated placeholder
_collectExpressions()source protected
_collectExpressions( array|Traversable $values )
Returns an array with the original $values in the first position and all ExpressionInterface objects that could be found in the second position.
Parameters
-
array|Traversable
$values
- The rows to insert
Returns
array_flattenValue()source protected
_flattenValue( array|Traversable $value , Cake\Database\ValueBinder $generator , string|array|null $type = 'string' )
Converts a traversable value into a set of placeholders generated by $generator and separated by ,
Parameters
-
array|Traversable
$value
- the value to flatten
-
Cake\Database\ValueBinder
$generator
- The value binder to use
-
string|array|null
$type
optional 'string' - the type to cast values to
Returns
string_stringExpression()source protected
_stringExpression( Cake\Database\ValueBinder $generator )
Returns a template and a placeholder for the value after registering it with the placeholder $generator
Parameters
-
Cake\Database\ValueBinder
$generator
- The value binder to use.
Returns
arrayFirst position containing the template and the second a placeholder
setOperator()source public
setOperator( string $operator )
Sets the operator to use for the comparison
Parameters
-
string
$operator
- The operator to be used for the comparison.
setValue()source public
setValue( mixed $value )
Sets the value
Parameters
-
mixed
$value
- The value to compare
sql()source public
sql( Cake\Database\ValueBinder $generator )
Convert the expression into a SQL fragment.
Parameters
-
Cake\Database\ValueBinder
$generator
- Placeholder generator object
Returns
stringImplementation of
Cake\Database\ExpressionInterface::sql()
traverse()source public
traverse( callable $callable )
Iterates over each part of the expression recursively for every level of the expressions tree and executes the $visitor callable passing as first parameter the instance of the expression currently being iterated.
Parameters
-
callable
$callable
- $visitor The callable to apply to all nodes.
Implementation of
Cake\Database\ExpressionInterface::traverse()
Methods used from Cake\Database\Type\ExpressionTypeCasterTrait
_castToExpression()source protected
_castToExpression( mixed $value , string $type )
Conditionally converts the passed value to an ExpressionInterface object if the type class implements the ExpressionTypeInterface. Otherwise, returns the value unmodified.
Parameters
-
mixed
$value
- The value to converto to ExpressionInterface
-
string
$type
- The type name
Returns
mixed_requiresToExpressionCasting()source protected
_requiresToExpressionCasting( array $types )
Returns an array with the types that require values to be casted to expressions, out of the list of type names passed as parameter.
Parameters
-
array
$types
- List of type names
Returns
arrayMethods used from Cake\Database\Expression\FieldTrait
getField()source public
getField( )
Returns the field name
Returns
string|Cake\Database\ExpressionInterface
setField()source public
setField( string|Cake\Database\ExpressionInterface $field )
Sets the field name
Parameters
-
string|
Cake\Database\ExpressionInterface
$field
- The field to compare with.
Properties detail
$_isMultiplesource
protected boolean
Whether or not the value in this expression is a traversable
false
$_typesource
protected string|array
The type to be used for casting the value to a database representation
$_valueExpressionssource
protected Cake\Database\ExpressionInterface[]
A cached list of ExpressionInterface objects that were found in the value for this expression.
[]
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https://api.cakephp.org/3.7/class-Cake.Database.Expression.Comparison.html