Package org.apache.sis.internal.sql.feature

Class Column

java.lang.Object

org.apache.sis.internal.sql.feature.Column

public final class Column
extends Object

Information (name, data type…) about a table column. It contains information extracted from database metadata, possibly completed with information about a geometry column. The aim is to describe all information about a column that is needed for mapping to feature model.

Multi-threading

Column instances shall be kept unmodified after all fields have been initialized. The same instances may be read concurrently by many threads.

Since:

1.1

Version:

1.2

Author:

Alexis Manin (Geomatys), Martin Desruisseaux (Geomatys)

See Also:

• ResultSet.getMetaData()
• DatabaseMetaData.getColumns(String, String, String, String)

Field Summary

Fields

Modifier and Type	Field	Description
final boolean	isNullable	Whether the column can have null values.
final String	label	Title to use for displays.
final String	name	Name of the column.
final int	type	Type of values as one of the constants enumerated in Types class.
final String	typeName	A name for the value type, free-text from the database engine.

Method Summary

Modifier and Type	Method	Description
final Optional<org.opengis.referencing.crs.CoordinateReferenceSystem>	getDefaultCRS()	If this column is a geometry or raster column, returns the default coordinate reference system.
final Optional<GeometryType>	getGeometryType()	If this column is a geometry column, returns the type of the geometry objects.
String	toString()	Returns a string representation for debugging purposes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

name

public final String name

Name of the column.

See Also:

• Reflection.COLUMN_NAME

label

public final String label

Title to use for displays. This is the name specified by the AS keyword in a SELECT clause. This is never null but may be identical to name if no label was specified.

type

public final int type

Type of values as one of the constants enumerated in Types class.

See Also:

• Reflection.DATA_TYPE

typeName

public final String typeName

A name for the value type, free-text from the database engine. For more information about this, see DatabaseMetaData.getColumns(String, String, String, String) and Reflection.TYPE_NAME. This value shall not be null.

See Also:

• Reflection.TYPE_NAME

isNullable

public final boolean isNullable

Whether the column can have null values.

See Also:

• Reflection.IS_NULLABLE

Method Details

getGeometryType

public final Optional<GeometryType> getGeometryType()

If this column is a geometry column, returns the type of the geometry objects. Otherwise returns empty (including the case where this is a raster column). Note that if this column is a geometry column but the geometry type was not defined, then GeometryType.GEOMETRY is returned as a fallback.

Returns:

type of geometry objects, or empty if this column is not a geometry column.

getDefaultCRS

public final Optional<org.opengis.referencing.crs.CoordinateReferenceSystem> getDefaultCRS()

If this column is a geometry or raster column, returns the default coordinate reference system. Otherwise returns empty. The CRS may also be empty even for a geometry column if it is unspecified.

Returns:

CRS of geometries or rasters in this column, or empty if unknown or not applicable.

toString

public String toString()

Returns a string representation for debugging purposes.

Overrides:

toString in class Object

Returns:

a string representation of this column.