@PublicEvolving public abstract class Column extends Object implements Serializable
Schema.
A table column describes either a PhysicalColumn or MetadataColumn.
| 限定符和类型 | 字段和说明 |
|---|---|
protected String |
comment |
protected String |
defaultValueExpression
Save the literal value of the column's default value, For uncertain functions such as UUID(),
the value is null, For the current time function such as CURRENT_TIMESTAMP(), the value is
Unix Epoch time(1970-01-01 00:00:00).
|
protected static String |
FIELD_FORMAT_NO_DESCRIPTION_NO_DEFAULT_VALUE_EXPRESSION |
protected static String |
FIELD_FORMAT_NO_DESCRIPTION_WITH_DEFAULT_VALUE_EXPRESSION |
protected static String |
FIELD_FORMAT_WITH_DESCRIPTION_NO_DEFAULT_VALUE_EXPRESSION |
protected static String |
FIELD_FORMAT_WITH_DESCRIPTION_WITH_DEFAULT_VALUE_EXPRESSION |
protected String |
name |
protected DataType |
type |
| 限定符 | 构造器和说明 |
|---|---|
protected |
Column(String name,
DataType type,
String comment) |
protected |
Column(String name,
DataType type,
String comment,
String defaultValueExpression) |
| 限定符和类型 | 方法和说明 |
|---|---|
String |
asSummaryString()
Returns a string that summarizes this column for printing to a console.
|
abstract Column |
copy(DataType newType)
Returns a copy of the column with a replaced
DataType. |
abstract Column |
copy(String newName)
Returns a copy of the column with a replaced name.
|
boolean |
equals(Object o) |
String |
getComment() |
String |
getDefaultValueExpression() |
String |
getName()
Returns the name of this column.
|
DataType |
getType()
Returns the data type of this column.
|
int |
hashCode() |
abstract boolean |
isPhysical()
Returns whether the given column is a physical column of a table or metadata column.
|
static MetadataColumn |
metadataColumn(String name,
DataType type)
Creates a metadata column.
|
static MetadataColumn |
metadataColumn(String name,
DataType type,
String metadataKey)
Creates a metadata column.
|
static MetadataColumn |
metadataColumn(String name,
DataType type,
String metadataKey,
String comment)
Creates a metadata column.
|
static PhysicalColumn |
physicalColumn(String name,
DataType type)
Creates a physical column.
|
static PhysicalColumn |
physicalColumn(String name,
DataType type,
String comment)
Creates a physical column.
|
static PhysicalColumn |
physicalColumn(String name,
DataType type,
String comment,
String defaultValueExpression)
Creates a physical column.
|
String |
toString() |
protected static final String FIELD_FORMAT_WITH_DESCRIPTION_NO_DEFAULT_VALUE_EXPRESSION
protected static final String FIELD_FORMAT_NO_DESCRIPTION_WITH_DEFAULT_VALUE_EXPRESSION
protected static final String FIELD_FORMAT_WITH_DESCRIPTION_WITH_DEFAULT_VALUE_EXPRESSION
protected static final String FIELD_FORMAT_NO_DESCRIPTION_NO_DEFAULT_VALUE_EXPRESSION
protected final String name
protected final DataType type
@Nullable protected final String defaultValueExpression
public String getName()
public DataType getType()
public String asSummaryString()
public abstract boolean isPhysical()
public abstract Column copy(DataType newType)
DataType.public static PhysicalColumn physicalColumn(String name, DataType type, @Nullable String comment, @Nullable String defaultValueExpression)
public static PhysicalColumn physicalColumn(String name, DataType type, @Nullable String comment)
public static PhysicalColumn physicalColumn(String name, DataType type)
public static MetadataColumn metadataColumn(String name, DataType type, @Nullable String metadataKey, @Nullable String comment)
public static MetadataColumn metadataColumn(String name, DataType type, @Nullable String metadataKey)
public static MetadataColumn metadataColumn(String name, DataType type)
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