io.delta.standalone.types

Class StructType

Object

io.delta.standalone.types.DataType

io.delta.standalone.types.StructType

public final class StructType
extends DataType

The data type representing a table's schema, consisting of a collection of fields (that is, fieldName to dataType pairs).

See Also:

StructField

Constructor Summary

Constructors

Constructor and Description
StructType()
StructType(StructField[] fields)

Method Summary

Modifier and Type	Method and Description
StructType	add(String fieldName, DataType dataType) Creates a new StructType by adding a new nullable field with no metadata.
StructType	add(String fieldName, DataType dataType, boolean nullable) Creates a new StructType by adding a new field with no metadata.
StructType	add(StructField field) Creates a new StructType by adding a new field.
Column	column(String fieldName) Creates a Column expression for the field with the given fieldName.
boolean	equals(Object o)
StructField	get(String fieldName)
String[]	getFieldNames()
StructField[]	getFields()
String	getTreeString()
int	hashCode()
boolean	isWriteCompatible(StructType newSchema) Whether a new schema can replace this existing schema in a Delta table without rewriting data files in the table.
int	length()

Methods inherited from class io.delta.standalone.types.DataType

equivalent, fromJson, getCatalogString, getSimpleString, getTypeName, toJson, toPrettyJson

Methods inherited from class Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StructType

public StructType()

StructType

public StructType(StructField[] fields)

Method Detail

add

public StructType add(StructField field)

Creates a new StructType by adding a new field.

 StructType schema = new StructType()
     .add(new StructField("a", new IntegerType(), true))
     .add(new StructField("b", new LongType(), false))
     .add(new StructField("c", new StringType(), true))
 

Parameters:

field - The new field to add.

Returns:

a StructType with the added field

add

public StructType add(String fieldName,
                      DataType dataType)

Creates a new StructType by adding a new nullable field with no metadata.

 StructType schema = new StructType()
     .add("a", new IntegerType())
     .add("b", new LongType())
     .add("c", new StringType())
 

Parameters:

fieldName - The name of the new field.

dataType - The datatype for the new field.

Returns:

a StructType with the added field

add

public StructType add(String fieldName,
                      DataType dataType,
                      boolean nullable)

Creates a new StructType by adding a new field with no metadata.

 StructType schema = new StructType()
     .add("a", new IntegerType(), true)
     .add("b", new LongType(), false)
     .add("c", new StringType(), true)
 

Parameters:

fieldName - The name of the new field.

dataType - The datatype for the new field.

nullable - Whether or not the new field is nullable.

Returns:

a StructType with the added field

getFields

public StructField[] getFields()

Returns:

array of fields

getFieldNames

public String[] getFieldNames()

Returns:

array of field names

length

public int length()

Returns:

the number of fields

get

public StructField get(String fieldName)

Parameters:

fieldName - the name of the desired StructField, not null

Returns:

the link with the given name, not null

Throws:

IllegalArgumentException - if a field with the given name does not exist

column

public Column column(String fieldName)

Creates a Column expression for the field with the given fieldName.

Parameters:

fieldName - the name of the StructField to create a column for

Returns:

a Column expression for the StructField with name fieldName

getTreeString

public String getTreeString()

Returns:

a readable indented tree representation of this StructType and all of its nested elements

equals

public boolean equals(Object o)

Overrides:

equals in class DataType

hashCode

public int hashCode()

Overrides:

hashCode in class DataType

isWriteCompatible

public boolean isWriteCompatible(StructType newSchema)

Whether a new schema can replace this existing schema in a Delta table without rewriting data files in the table.

Returns false if the new schema:

• Drops any column that is present in the current schema
• Converts nullable=true to nullable=false for any column
• Changes any datatype

Parameters:

newSchema - the new schema to update the table with

Returns:

whether the new schema is compatible with this existing schema