Class: QgsField¶
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class
qgis.core.
QgsField
(name: str = '', type: QVariant.Type = QVariant.Invalid, typeName: str = '', len: int = 0, prec: int = 0, comment: str = '', subType: QVariant.Type = QVariant.Invalid)¶ Bases:
sip.wrapper
Constructor. Constructs a new QgsField object.
- Parameters
name – Field name
type – Field variant type, currently supported: String / Int / Double
typeName – Field type (e.g., char, varchar, text, int, serial, double). Field types are usually unique to the source and are stored exactly as returned from the data store.
len – Field length
prec – Field precision. Usually decimal places but may also be used in conjunction with other fields types (e.g., variable character fields)
comment – Comment for the field
subType – If the field is a collection, its element’s type. When all the elements don’t need to have the same type, leave this to QVariant.Invalid.
QgsField(other: QgsField) Copy constructor
Encapsulate a field in an attribute table or data source. QgsField stores metadata about an attribute field, including name, type length, and if applicable, precision.
Note
QgsField objects are implicitly shared.
Enums
Methods
Returns the alias for the field (the friendly displayed name of the field ), or an empty string if there is no alias.
Returns the field comment
Returns constraints which are present for the field.
Converts the provided variant to a compatible format
Returns the expression used when calculating the default value for the field.
Returns the name to use when displaying this field.
Formats string for display
Gets the editor widget setup for the field.
Returns if this field is a date and/or time type.
Returns if this field is numeric.
Gets the length of the field.
Returns the name of the field.
Gets the precision of the field.
Sets the alias for the field (the friendly displayed name of the field ).
Set the field comment
Sets constraints which are present for the field.
Sets an expression to use when calculating the default value for the field.
Set the editor widget setup for the field.
Set the field length.
Set the field name.
Set the field precision.
If the field is a collection, set its element’s type.
Set variant type.
Set the field type.
If the field is a collection, gets its element’s type.
Gets variant type of the field as it will be retrieved from data source
Gets the field type.
Signals
Attributes
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alias
(self) → str¶ Returns the alias for the field (the friendly displayed name of the field ), or an empty string if there is no alias.
See also
New in version 3.0.
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comment
(self) → str¶ Returns the field comment
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constraints
(self) → QgsFieldConstraints¶ Returns constraints which are present for the field.
See also
New in version 3.0.
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convertCompatible
(self, v: Any) → bool¶ Converts the provided variant to a compatible format
- Parameters
v – The value to convert
- Returns
True
if the conversion was successful
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defaultValueDefinition
(self) → QgsDefaultValue¶ Returns the expression used when calculating the default value for the field.
- Returns
expression evaluated when calculating default values for field, or an empty string if no default is set
See also
New in version 3.0.
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displayName
(self) → str¶ Returns the name to use when displaying this field. This will be the field alias if set, otherwise the field name.
See also
See also
New in version 3.0.
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displayString
(self, v: Any) → str¶ Formats string for display
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editorWidgetSetup
(self) → QgsEditorWidgetSetup¶ Gets the editor widget setup for the field.
Defaults may be set by the provider and can be overridden by manual field configuration.
- Returns
the value
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isDateOrTime
(self) → bool¶ Returns if this field is a date and/or time type.
New in version 3.6.
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isNumeric
(self) → bool¶ Returns if this field is numeric. Any integer or floating point type will return
True
for this.New in version 2.18.
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length
(self) → int¶ Gets the length of the field.
- Returns
int containing the length of the field
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name
(self) → str¶ Returns the name of the field.
See also
See also
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precision
(self) → int¶ Gets the precision of the field. Not all field types have a related precision.
- Returns
int containing the precision or zero if not applicable to the field type.
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setAlias
(self, alias: str)¶ Sets the alias for the field (the friendly displayed name of the field ).
- Parameters
alias – field alias, or empty string to remove an existing alias
See also
New in version 3.0.
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setComment
(self, comment: str)¶ Set the field comment
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setConstraints
(self, constraints: QgsFieldConstraints)¶ Sets constraints which are present for the field.
See also
New in version 3.0.
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setDefaultValueDefinition
(self, defaultValueDefinition: QgsDefaultValue)¶ Sets an expression to use when calculating the default value for the field.
- Parameters
defaultValueDefinition – expression to evaluate when calculating default values for field. Pass a default constructed :py:class:`QgsDefaultValue`() to reset.
See also
New in version 3.0.
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setEditorWidgetSetup
(self, v: QgsEditorWidgetSetup)¶ Set the editor widget setup for the field.
- Parameters
v – The value to set
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setLength
(self, len: int)¶ Set the field length.
- Parameters
len – Length of the field
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setName
(self, name: str)¶ Set the field name.
- Parameters
name – Name of the field
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setPrecision
(self, precision: int)¶ Set the field precision.
- Parameters
precision – Precision of the field
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setSubType
(self, subType: QVariant.Type)¶ If the field is a collection, set its element’s type. When all the elements don’t need to have the same type, set this to QVariant.Invalid.
New in version 3.0.
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setType
(self, type: QVariant.Type)¶ Set variant type.
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setTypeName
(self, typeName: str)¶ Set the field type.
- Parameters
typeName – Field type
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staticMetaObject
= <PyQt5.QtCore.QMetaObject object>¶
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subType
(self) → QVariant.Type¶ If the field is a collection, gets its element’s type. When all the elements don’t need to have the same type, this returns QVariant.Invalid.
New in version 3.0.
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type
(self) → QVariant.Type¶ Gets variant type of the field as it will be retrieved from data source
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typeName
(self) → str¶ Gets the field type. Field types vary depending on the data source. Examples are char, int, double, blob, geometry, etc. The type is stored exactly as the data store reports it, with no attempt to standardize the value.
- Returns
QString containing the field type