org.apache.calcite.sql

Class SqlUnpivot

java.lang.Object

org.apache.calcite.sql.SqlNode

org.apache.calcite.sql.SqlCall

org.apache.calcite.sql.SqlUnpivot

All Implemented Interfaces:

Cloneable

public class SqlUnpivot
extends SqlCall

Parse tree node that represents UNPIVOT applied to a table reference (or sub-query).

Syntax:

 SELECT *
 FROM query
 UNPIVOT [ { INCLUDE | EXCLUDE } NULLS ] (
   columns FOR columns IN ( columns [ AS values ], ...))

 where:

 columns: column
        | '(' column, ... ')'
 values:  value
        | '(' value, ... ')'
 

Field Summary

Fields

Modifier and Type	Field and Description
SqlNodeList	axisList
boolean	includeNulls
SqlNodeList	inList
SqlNodeList	measureList
SqlNode	query

Fields inherited from class org.apache.calcite.sql.SqlNode

EMPTY_ARRAY, pos

Constructor Summary

Constructors

Constructor and Description
SqlUnpivot(SqlParserPos pos, SqlNode query, boolean includeNulls, SqlNodeList measureList, SqlNodeList axisList, SqlNodeList inList)

Method Summary

Modifier and Type	Method and Description
static String	aliasValue(SqlNodeList aliasList) Computes an alias.
void	forEachMeasure(Consumer<SqlIdentifier> consumer) Returns the measure list as SqlIdentifiers.
void	forEachNameValues(BiConsumer<SqlNodeList,SqlNodeList> consumer) Returns contents of the IN clause (nodeList, valueList) pairs.
List<SqlNode>	getOperandList() Returns the list of operands.
SqlOperator	getOperator()
void	setOperand(int i, @Nullable SqlNode operand) Changes the value of an operand.
void	unparse(SqlWriter writer, int leftPrec, int rightPrec) Writes a SQL representation of this node to a writer.
Set<String>	usedColumnNames() Returns the set of columns that are referenced in the FOR clause.

Methods inherited from class org.apache.calcite.sql.SqlCall

accept, clone, equalsDeep, findValidOptions, getCallSignature, getFunctionQuantifier, getKind, getMonotonicity, isCountStar, isExpanded, operand, operandCount, validate

Methods inherited from class org.apache.calcite.sql.SqlNode

clone, clone, cloneArray, equalDeep, equalDeep, equalsDeep, getParserPosition, isA, toList, toList, toSqlString, toSqlString, toSqlString, toString, unparseWithParentheses, validateExpr

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

query

public SqlNode query

includeNulls

public final boolean includeNulls

measureList

public final SqlNodeList measureList

axisList

public final SqlNodeList axisList

inList

public final SqlNodeList inList

Constructor Detail

SqlUnpivot

public SqlUnpivot(SqlParserPos pos,
                  SqlNode query,
                  boolean includeNulls,
                  SqlNodeList measureList,
                  SqlNodeList axisList,
                  SqlNodeList inList)

Method Detail

getOperator

public SqlOperator getOperator()

Specified by:

getOperator in class SqlCall

getOperandList

public List<SqlNode> getOperandList()

Description copied from class: SqlCall

Returns the list of operands. The set and order of operands is call-specific.

Note: the proper type would be List<@Nullable SqlNode>, however, it would trigger too many changes to the current codebase.

Specified by:

getOperandList in class SqlCall

Returns:

the list of call operands, never null, the operands can be null

setOperand

public void setOperand(int i,
                       @Nullable SqlNode operand)

Description copied from class: SqlCall

Changes the value of an operand. Allows some rewrite by SqlValidator; use sparingly.

Overrides:

setOperand in class SqlCall

Parameters:

i - Operand index

operand - Operand value

unparse

public void unparse(SqlWriter writer,
                    int leftPrec,
                    int rightPrec)

Description copied from class: SqlNode

Writes a SQL representation of this node to a writer.

The leftPrec and rightPrec parameters give us enough context to decide whether we need to enclose the expression in parentheses. For example, we need parentheses around "2 + 3" if preceded by "5 *". This is because the precedence of the "*" operator is greater than the precedence of the "+" operator.

The algorithm handles left- and right-associative operators by giving them slightly different left- and right-precedence.

If SqlWriter.isAlwaysUseParentheses() is true, we use parentheses even when they are not required by the precedence rules.

For the details of this algorithm, see SqlCall.unparse(org.apache.calcite.sql.SqlWriter, int, int).

Overrides:

unparse in class SqlCall

Parameters:

writer - Target writer

leftPrec - The precedence of the SqlNode immediately preceding this node in a depth-first scan of the parse tree

rightPrec - The precedence of the SqlNode immediately

forEachMeasure

public void forEachMeasure(Consumer<SqlIdentifier> consumer)

Returns the measure list as SqlIdentifiers.

forEachNameValues

public void forEachNameValues(BiConsumer<SqlNodeList,SqlNodeList> consumer)

Returns contents of the IN clause (nodeList, valueList) pairs. valueList is null if the entry has no AS clause.

usedColumnNames

public Set<String> usedColumnNames()

Returns the set of columns that are referenced in the FOR clause. All columns that are not used will be part of the returned row.

aliasValue

public static String aliasValue(SqlNodeList aliasList)

Computes an alias. In the query fragment

UNPIVOT ... FOR ... IN ((c1, c2) AS 'c1_c2', (c3, c4))

note that (c3, c4) has no AS. The computed alias is 'C3_C4'.