org.apache.spark.sql.util

Class SchemaUtils

Object

org.apache.spark.sql.util.SchemaUtils

public class SchemaUtils
extends Object

Utils for handling schemas.

TODO: Merge this file with SchemaUtils.

Constructor Summary

Constructors

Constructor and Description
SchemaUtils()

Method Summary

Modifier and Type	Method and Description
static void	checkColumnNameDuplication(scala.collection.Seq<String> columnNames, boolean caseSensitiveAnalysis) Checks if input column names have duplicate identifiers.
static void	checkColumnNameDuplication(scala.collection.Seq<String> columnNames, scala.Function2<String,String,Object> resolver) Checks if input column names have duplicate identifiers.
static void	checkSchemaColumnNameDuplication(DataType schema, boolean caseSensitiveAnalysis) Checks if an input schema has duplicate column names.
static void	checkSchemaColumnNameDuplication(StructType schema, scala.Function2<String,String,Object> resolver) Checks if an input schema has duplicate column names.
static void	checkTransformDuplication(scala.collection.Seq<Transform> transforms, String checkType, boolean isCaseSensitive) Checks if the partitioning transforms are being duplicated or not.
static String	escapeMetaCharacters(String str)
static scala.collection.Seq<String>	explodeNestedFieldNames(StructType schema) Returns all column names in this schema as a flat list.
static scala.collection.Seq<Object>	findColumnPosition(scala.collection.Seq<String> column, StructType schema, scala.Function2<String,String,Object> resolver) Returns the given column's ordinal within the given schema.
static scala.collection.Seq<String>	getColumnName(scala.collection.Seq<Object> position, StructType schema) Gets the name of the column in the given position.
static scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.NamedExpression>	restoreOriginalOutputNames(scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.NamedExpression> projectList, scala.collection.Seq<String> originalNames)

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SchemaUtils

public SchemaUtils()

Method Detail

checkSchemaColumnNameDuplication

public static void checkSchemaColumnNameDuplication(DataType schema,
                                                    boolean caseSensitiveAnalysis)

Checks if an input schema has duplicate column names. This throws an exception if the duplication exists.

Parameters:

schema - schema to check

caseSensitiveAnalysis - whether duplication checks should be case sensitive or not

checkSchemaColumnNameDuplication

public static void checkSchemaColumnNameDuplication(StructType schema,
                                                    scala.Function2<String,String,Object> resolver)

Checks if an input schema has duplicate column names. This throws an exception if the duplication exists.

Parameters:

schema - schema to check

resolver - resolver used to determine if two identifiers are equal

checkColumnNameDuplication

public static void checkColumnNameDuplication(scala.collection.Seq<String> columnNames,
                                              scala.Function2<String,String,Object> resolver)

Checks if input column names have duplicate identifiers. This throws an exception if the duplication exists.

Parameters:

columnNames - column names to check

resolver - resolver used to determine if two identifiers are equal

checkColumnNameDuplication

public static void checkColumnNameDuplication(scala.collection.Seq<String> columnNames,
                                              boolean caseSensitiveAnalysis)

Checks if input column names have duplicate identifiers. This throws an exception if the duplication exists.

Parameters:

columnNames - column names to check

caseSensitiveAnalysis - whether duplication checks should be case sensitive or not

explodeNestedFieldNames

public static scala.collection.Seq<String> explodeNestedFieldNames(StructType schema)

Returns all column names in this schema as a flat list. For example, a schema like: | - a | | - 1 | | - 2 | - b | - c | | - nest | | - 3 will get flattened to: "a", "a.1", "a.2", "b", "c", "c.nest", "c.nest.3"

Parameters:

schema - (undocumented)

Returns:

(undocumented)

checkTransformDuplication

public static void checkTransformDuplication(scala.collection.Seq<Transform> transforms,
                                             String checkType,
                                             boolean isCaseSensitive)

Checks if the partitioning transforms are being duplicated or not. Throws an exception if duplication exists.

Parameters:

transforms - the schema to check for duplicates

checkType - contextual information around the check, used in an exception message

isCaseSensitive - Whether to be case sensitive when comparing column names

findColumnPosition

public static scala.collection.Seq<Object> findColumnPosition(scala.collection.Seq<String> column,
                                                              StructType schema,
                                                              scala.Function2<String,String,Object> resolver)

Returns the given column's ordinal within the given schema. The length of the returned position will be as long as how nested the column is.

Parameters:

column - The column to search for in the given struct. If the length of column is greater than 1, we expect to enter a nested field.

schema - The current struct we are looking at.

resolver - The resolver to find the column.

Returns:

(undocumented)

getColumnName

public static scala.collection.Seq<String> getColumnName(scala.collection.Seq<Object> position,
                                                         StructType schema)

Gets the name of the column in the given position.

Parameters:

position - (undocumented)

schema - (undocumented)

Returns:

(undocumented)

restoreOriginalOutputNames

public static scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.NamedExpression> restoreOriginalOutputNames(scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.NamedExpression> projectList,
                                                                                                                         scala.collection.Seq<String> originalNames)

escapeMetaCharacters

public static String escapeMetaCharacters(String str)

Parameters:

str - The string to be escaped.

Returns:

The escaped string.