ColumnSchema

API reference › yii › db › mysql › ColumnSchema

class	`yii\db\mysql\ColumnSchema`
Extends	`yii\db\ColumnSchema` » `yii\base\BaseObject`
Implements	`yii\base\Configurable`
Since	2.0.14.1
Source	`framework/db/mysql/ColumnSchema.php`

Represents the metadata of a column in a MySQL database table.

Properties

Property	Type	Description	Defined by
`$allowNull`	`bool`	Whether this column can be null. Default: `false`.	`yii\db\ColumnSchema`
`$autoIncrement`	`bool`	Whether this column is auto-incremental Default: `false`.	`yii\db\ColumnSchema`
`$comment`	`string\|null`	Comment of this column. Default: `null`.	`yii\db\ColumnSchema`
`$dbType`	`string`	The DB type of this column. Default: `''`.	`yii\db\ColumnSchema`
`$defaultValue`	`mixed`	Default value of this column Default: `null`.	`yii\db\ColumnSchema`
`$enumValues`	`array\|null`	Enumerable values. Default: `null`.	`yii\db\ColumnSchema`
`$isDefaultExpression`	`bool`	Whether MySQL reports the column default as an expression (`DEFAULT_GENERATED`). Default: `false`. Available since 22.0.	`ColumnSchema`
`$isPrimaryKey`	`bool\|null`	Whether this column is a primary key Default: `null`.	`yii\db\ColumnSchema`
`$name`	`string`	Name of this column (without quotes). Default: `''`.	`yii\db\ColumnSchema`
`$phpType`	`string`	The PHP type of this column. Default: `''`.	`yii\db\ColumnSchema`
`$precision`	`int\|null`	Precision of the column data, if it is numeric. Default: `null`.	`yii\db\ColumnSchema`
`$scale`	`int\|null`	Scale of the column data, if it is numeric. Default: `null`.	`yii\db\ColumnSchema`
`$size`	`int\|null`	Display size of the column. Default: `null`.	`yii\db\ColumnSchema`
`$type`	`string`	Abstract type of this column. Default: `''`.	`yii\db\ColumnSchema`
`$unsigned`	`bool`	Whether this column is unsigned. Default: `false`.	`yii\db\ColumnSchema`

Methods

Method	Description	Defined by
`__construct()`	Constructor.	`yii\base\BaseObject`
`__call()`	Calls the named method which is not a class method.	`yii\base\BaseObject`
`__get()`	Returns the value of an object property.	`yii\base\BaseObject`
`__isset()`	Checks if a property is set, i.e. defined and not null.	`yii\base\BaseObject`
`__set()`	Sets value of an object property.	`yii\base\BaseObject`
`__unset()`	Sets an object property to null.	`yii\base\BaseObject`
`canGetProperty()`	Returns a value indicating whether a property can be read.	`yii\base\BaseObject`
`canSetProperty()`	Returns a value indicating whether a property can be set.	`yii\base\BaseObject`
`className()` static	Returns the fully qualified name of this class.	`yii\base\BaseObject`
`dbTypecast()`	Converts the input value according to `$type` and `$dbType` for use in a db query.	`ColumnSchema`
`defaultPhpTypecast()`	Converts a MySQL column default value to its PHP representation.	`ColumnSchema`
`hasMethod()`	Returns a value indicating whether a method is defined.	`yii\base\BaseObject`
`hasProperty()`	Returns a value indicating whether a property is defined.	`yii\base\BaseObject`
`init()`	Initializes the object.	`yii\base\BaseObject`
`isType()`	Returns whether this column uses the given abstract type.	`yii\db\ColumnSchema`
`phpTypecast()`	Converts the input value according to `$phpType` after retrieval from the database.	`ColumnSchema`
`typecast()` protected	Converts the input value according to `$phpType` after retrieval from the database.	`yii\db\ColumnSchema`

Method details

dbTypecast()

public function dbTypecast(mixed $value): mixed

Converts the input value according to $type and $dbType for use in a db query.

If the value is null or an Expression, it will not be converted.

Parameters

Parameter	Type	Description
`$value`	`mixed`	Input value

Returns

mixed: Converted value. This may also be an array containing the value as the first element and the PDO type as the second element.

defaultPhpTypecast()

public function defaultPhpTypecast(mixed $value): mixed

Converts a MySQL column default value to its PHP representation.

Handles MySQL-specific default value formats:

null to null.
CURRENT_TIMESTAMP / current_timestamp() on temporal columns (timestamp, datetime, date, time) to an Expression, preserving any declared fractional-seconds precision such as CURRENT_TIMESTAMP(3).
quoted string literals on text and blob columns, and on any column flagged through $isDefaultExpression, to their PHP value: the character-set introducer MySQL prepends is discarded and the escape sequences in \yii\db\mysql\DEFAULT_LITERAL_ESCAPES are resolved. json columns are exempt.
remaining expression defaults flagged through $isDefaultExpression to an Expression.
json defaults without the flag to their decoded value when the string is valid JSON, or to an Expression otherwise; MariaDB reports expression-form defaults without metadata.
remaining text defaults without the flag to an Expression, preserving MariaDB’s expression-form SQL.
bit defaults (b'...') when $dbType starts with bit to their integer value via bindec().
everything else delegates to phpTypecast().

Branch order is significant: MySQL also flags plain CURRENT_TIMESTAMP defaults as DEFAULT_GENERATED, so the normalization above must win over the generic expression wrapping. Flagged defaults carry an extra metadata escape layer (\', \\) that is removed before literal parsing; MariaDB reports the expression verbatim.

Parameters

Parameter	Type	Description
`$value`	`mixed`	Default value in the format reported by `SHOW FULL COLUMNS`.

Returns

mixed: Converted value.

Since

22.0

phpTypecast()

public function phpTypecast(mixed $value): mixed

Converts the input value according to $phpType after retrieval from the database.

If the value is null or an Expression, it will not be converted.

Parameters

Parameter	Type	Description
`$value`	`mixed`	Input value

Returns

mixed: Converted value