org.apache.gravitino.rel

Interface Column

All Known Implementing Classes:

Column.ColumnImpl, ColumnDTO

@Evolving
public interface Column

An interface representing a column of a Table. It defines basic properties of a column, such as name and data type.

Catalog implementation needs to implement it. They should consume it in APIs like TableCatalog.createTable(NameIdentifier, Column[], String, Map), and report it in Table.columns() a default value and a generation expression.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Column.ColumnImpl The implementation of Column for users to use API.

Field Summary

Fields

Modifier and Type	Field and Description
static Expression	DEFAULT_VALUE_NOT_SET A default value that indicates the default value is not set.
static Expression	DEFAULT_VALUE_OF_CURRENT_TIMESTAMP A default value that indicates the default value will be set to the current timestamp.

Method Summary

Modifier and Type	Method and Description
boolean	autoIncrement()
java.lang.String	comment()
Type	dataType()
Expression	defaultValue()
java.lang.String	name()
boolean	nullable()
static Column.ColumnImpl	of(java.lang.String name, Type dataType) Create a Column instance.
static Column.ColumnImpl	of(java.lang.String name, Type dataType, java.lang.String comment) Create a Column instance.
static Column.ColumnImpl	of(java.lang.String name, Type dataType, java.lang.String comment, boolean nullable, boolean autoIncrement, Expression defaultValue) Create a Column instance.
static Column.ColumnImpl	of(java.lang.String name, Type dataType, java.lang.String comment, Expression defaultValue) Create a Column instance.

Field Detail

DEFAULT_VALUE_NOT_SET

static final Expression DEFAULT_VALUE_NOT_SET

A default value that indicates the default value is not set. This is used in defaultValue().

DEFAULT_VALUE_OF_CURRENT_TIMESTAMP

static final Expression DEFAULT_VALUE_OF_CURRENT_TIMESTAMP

A default value that indicates the default value will be set to the current timestamp. This is used in defaultValue().

Method Detail

name

java.lang.String name()

Returns:

The name of this column.

dataType

Type dataType()

Returns:

The data type of this column.

comment

java.lang.String comment()

Returns:

The comment of this column, null if not specified.

nullable

boolean nullable()

Returns:

True if this column may produce null values. Default is true.

autoIncrement

boolean autoIncrement()

Returns:

True if this column is an auto-increment column. Default is false.

defaultValue

Expression defaultValue()

Returns:

The default value of this column, DEFAULT_VALUE_NOT_SET if not specified

of

static Column.ColumnImpl of(java.lang.String name,
                            Type dataType,
                            java.lang.String comment,
                            Expression defaultValue)

Create a Column instance.

Parameters:

name - The name of the column.

dataType - The data type of the column.

comment - The comment of the column.

defaultValue - The default value of the column. DEFAULT_VALUE_NOT_SET if null.

Returns:

A Column instance.

of

static Column.ColumnImpl of(java.lang.String name,
                            Type dataType,
                            java.lang.String comment)

Create a Column instance.

Parameters:

name - The name of the column.

dataType - The data type of the column.

comment - The comment of the column.

Returns:

A Column instance.

of

static Column.ColumnImpl of(java.lang.String name,
                            Type dataType)

Create a Column instance.

Parameters:

name - The name of the column.

dataType - The data type of the column.

Returns:

A Column instance.

of

static Column.ColumnImpl of(java.lang.String name,
                            Type dataType,
                            java.lang.String comment,
                            boolean nullable,
                            boolean autoIncrement,
                            Expression defaultValue)

Create a Column instance.

Parameters:

name - The name of the column.

dataType - The data type of the column.

comment - The comment of the column.

nullable - True if the column may produce null values.

autoIncrement - True if the column is an auto-increment column.

defaultValue - The default value of the column. DEFAULT_VALUE_NOT_SET if null.

Returns:

A Column instance.