org.apache.spark.sql

Class Column

Object

org.apache.spark.sql.Column

Direct Known Subclasses:

ColumnName

public class Column
extends Object

:: Experimental :: A column in a DataFrame.

Constructor Summary

Constructors

Constructor and Description
Column(org.apache.spark.sql.catalyst.expressions.Expression expr)
Column(String name)

Method Summary

Methods

Modifier and Type	Method and Description
Column	and(Column other) Boolean AND.
static Column	apply(org.apache.spark.sql.catalyst.expressions.Expression expr)
static Column	apply(String colName)
Column	as(String alias) Gives the column an alias.
Column	as(scala.Symbol alias) Gives the column an alias.
Column	asc() Returns an ordering used in sorting.
Column	cast(org.apache.spark.sql.types.DataType to) Casts the column to a different data type.
Column	cast(String to) Casts the column to a different data type, using the canonical string representation of the type.
Column	contains(Object other) Contains the other element.
Column	desc() Returns an ordering used in sorting.
Column	divide(Object other) Division this expression by another expression.
Column	endsWith(Column other) String ends with.
Column	endsWith(String literal) String ends with another string literal.
Column	eqNullSafe(Object other) Equality test that is safe for null values.
boolean	equals(Object that)
Column	equalTo(Object other) Equality test.
void	explain(boolean extended) Prints the expression to the console for debugging purpose.
Column	geq(Object other) Greater than or equal to an expression.
Column	getField(String fieldName) An expression that gets a field by name in a StructField.
Column	getItem(int ordinal) An expression that gets an item at position ordinal out of an array.
Column	gt(Object other) Greater than.
int	hashCode()
Column	in(Column... list) A boolean expression that is evaluated to true if the value of this expression is contained by the evaluated values of the arguments.
Column	in(scala.collection.Seq<Column> list) A boolean expression that is evaluated to true if the value of this expression is contained by the evaluated values of the arguments.
Column	isNotNull() True if the current expression is NOT null.
Column	isNull() True if the current expression is null.
Column	leq(Object other) Less than or equal to.
Column	like(String literal) SQL like expression.
Column	lt(Object other) Less than.
Column	minus(Object other) Subtraction.
Column	mod(Object other) Modulo (a.k.a.
Column	multiply(Object other) Multiplication of this expression and another expression.
Column	notEqual(Object other) Inequality test.
Column	or(Column other) Boolean OR.
Column	plus(Object other) Sum of this expression and another expression.
Column	rlike(String literal) SQL RLIKE expression (LIKE with Regex).
Column	startsWith(Column other) String starts with.
Column	startsWith(String literal) String starts with another string literal.
Column	substr(Column startPos, Column len) An expression that returns a substring.
Column	substr(int startPos, int len) An expression that returns a substring.
String	toString()
static scala.Option<org.apache.spark.sql.catalyst.expressions.Expression>	unapply(Column col)

Methods inherited from class Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Column

public Column(org.apache.spark.sql.catalyst.expressions.Expression expr)

Column

public Column(String name)

Method Detail

apply

public static Column apply(String colName)

apply

public static Column apply(org.apache.spark.sql.catalyst.expressions.Expression expr)

unapply

public static scala.Option<org.apache.spark.sql.catalyst.expressions.Expression> unapply(Column col)

in

public Column in(Column... list)

A boolean expression that is evaluated to true if the value of this expression is contained by the evaluated values of the arguments.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object that)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equalTo

public Column equalTo(Object other)

Equality test.

   // Scala:
   df.filter( df("colA") === df("colB") )

   // Java
   import static org.apache.spark.sql.functions.*;
   df.filter( col("colA").equalTo(col("colB")) );
 

notEqual

public Column notEqual(Object other)

Inequality test.

   // Scala:
   df.select( df("colA") !== df("colB") )
   df.select( !(df("colA") === df("colB")) )

   // Java:
   import static org.apache.spark.sql.functions.*;
   df.filter( col("colA").notEqual(col("colB")) );
 

gt

public Column gt(Object other)

Greater than.

   // Scala: The following selects people older than 21.
   people.select( people("age") > lit(21) )

   // Java:
   import static org.apache.spark.sql.functions.*;
   people.select( people("age").gt(21) );
 

lt

public Column lt(Object other)

Less than.

   // Scala: The following selects people younger than 21.
   people.select( people("age") < 21 )

   // Java:
   people.select( people("age").lt(21) );
 

leq

public Column leq(Object other)

Less than or equal to.

   // Scala: The following selects people age 21 or younger than 21.
   people.select( people("age") <= 21 )

   // Java:
   people.select( people("age").leq(21) );
 

geq

public Column geq(Object other)

Greater than or equal to an expression.

   // Scala: The following selects people age 21 or older than 21.
   people.select( people("age") >= 21 )

   // Java:
   people.select( people("age").geq(21) )
 

eqNullSafe

public Column eqNullSafe(Object other)

Equality test that is safe for null values.

isNull

public Column isNull()

True if the current expression is null.

isNotNull

public Column isNotNull()

True if the current expression is NOT null.

or

public Column or(Column other)

Boolean OR.

   // Scala: The following selects people that are in school or employed.
   people.filter( people("inSchool") || people("isEmployed") )

   // Java:
   people.filter( people("inSchool").or(people("isEmployed")) );
 

and

public Column and(Column other)

Boolean AND.

   // Scala: The following selects people that are in school and employed at the same time.
   people.select( people("inSchool") && people("isEmployed") )

   // Java:
   people.select( people("inSchool").and(people("isEmployed")) );
 

plus

public Column plus(Object other)

Sum of this expression and another expression.

   // Scala: The following selects the sum of a person's height and weight.
   people.select( people("height") + people("weight") )

   // Java:
   people.select( people("height").plus(people("weight")) );
 

minus

public Column minus(Object other)

Subtraction. Subtract the other expression from this expression.

   // Scala: The following selects the difference between people's height and their weight.
   people.select( people("height") - people("weight") )

   // Java:
   people.select( people("height").minus(people("weight")) );
 

multiply

public Column multiply(Object other)

Multiplication of this expression and another expression.

   // Scala: The following multiplies a person's height by their weight.
   people.select( people("height") * people("weight") )

   // Java:
   people.select( people("height").multiply(people("weight")) );
 

divide

public Column divide(Object other)

Division this expression by another expression.

   // Scala: The following divides a person's height by their weight.
   people.select( people("height") / people("weight") )

   // Java:
   people.select( people("height").divide(people("weight")) );
 

mod

public Column mod(Object other)

Modulo (a.k.a. remainder) expression.

in

public Column in(scala.collection.Seq<Column> list)

A boolean expression that is evaluated to true if the value of this expression is contained by the evaluated values of the arguments.

like

public Column like(String literal)

SQL like expression.

rlike

public Column rlike(String literal)

SQL RLIKE expression (LIKE with Regex).

getItem

public Column getItem(int ordinal)

An expression that gets an item at position ordinal out of an array.

getField

public Column getField(String fieldName)

An expression that gets a field by name in a StructField.

substr

public Column substr(Column startPos,
            Column len)

An expression that returns a substring.

Parameters:

startPos - expression for the starting position.

len - expression for the length of the substring.

substr

public Column substr(int startPos,
            int len)

An expression that returns a substring.

Parameters:

startPos - starting position.

len - length of the substring.

contains

public Column contains(Object other)

Contains the other element.

startsWith

public Column startsWith(Column other)

String starts with.

startsWith

public Column startsWith(String literal)

String starts with another string literal.

endsWith

public Column endsWith(Column other)

String ends with.

endsWith

public Column endsWith(String literal)

String ends with another string literal.

as

public Column as(String alias)

Gives the column an alias.

   // Renames colA to colB in select output.
   df.select($"colA".as("colB"))
 

as

public Column as(scala.Symbol alias)

Gives the column an alias.

   // Renames colA to colB in select output.
   df.select($"colA".as('colB))
 

cast

public Column cast(org.apache.spark.sql.types.DataType to)

Casts the column to a different data type.

   // Casts colA to IntegerType.
   import org.apache.spark.sql.types.IntegerType
   df.select(df("colA").cast(IntegerType))

   // equivalent to
   df.select(df("colA").cast("int"))
 

cast

public Column cast(String to)

Casts the column to a different data type, using the canonical string representation of the type. The supported types are: string, boolean, byte, short, int, long, float, double, decimal, date, timestamp.

   // Casts colA to integer.
   df.select(df("colA").cast("int"))
 

desc

public Column desc()

Returns an ordering used in sorting.

   // Scala: sort a DataFrame by age column in descending order.
   df.sort(df("age").desc)

   // Java
   df.sort(df.col("age").desc());
 

asc

public Column asc()

Returns an ordering used in sorting.

   // Scala: sort a DataFrame by age column in ascending order.
   df.sort(df("age").asc)

   // Java
   df.sort(df.col("age").asc());
 

explain

public void explain(boolean extended)

Prints the expression to the console for debugging purpose.