org.apache.calcite.rel.rel2sql

Class SqlImplementor.Result

java.lang.Object

org.apache.calcite.rel.rel2sql.SqlImplementor.Result

Enclosing class:

SqlImplementor

public class SqlImplementor.Result
extends Object

Result of implementing a node.

Field Summary

Fields

Modifier and Type	Field and Description
private Map<String,RelDataType>	aliases
(package private) Expressions.FluentList<SqlImplementor.Clause>	clauses
private String	neededAlias
private RelDataType	neededType
(package private) SqlNode	node

Constructor Summary

Constructors

Constructor and Description
Result(SqlNode node, Collection<SqlImplementor.Clause> clauses, String neededAlias, RelDataType neededType, Map<String,RelDataType> aliases)

Method Summary

Modifier and Type	Method and Description
SqlNode	asFrom() Returns a node that can be included in the FROM clause or a JOIN.
SqlNode	asQueryOrValues() Converts a non-query node into a SELECT node.
SqlSelect	asSelect() Converts a non-query node into a SELECT node.
SqlNode	asStatement() Converts a non-query node into a SELECT node.
SqlImplementor.Builder	builder(RelNode rel, SqlImplementor.Clause... clauses) Once you have a Result of implementing a child relational expression, call this method to create a Builder to implement the current relational expression by adding additional clauses to the SQL query.
private boolean	hasNestedAggregations(LogicalAggregate rel)
SqlImplementor.Clause	maxClause()
SqlImplementor.Context	qualifiedContext() Returns a context that always qualifies identifiers.
SqlImplementor.Result	resetAlias() In join, when the left and right nodes have been generated, update their alias with 'neededAlias' if not null.
SqlSelect	subSelect()

Methods inherited from class java.lang.Object

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

Field Detail

node

final SqlNode node

neededAlias

private final String neededAlias

neededType

private final RelDataType neededType

aliases

private final Map<String,RelDataType> aliases

clauses

final Expressions.FluentList<SqlImplementor.Clause> clauses

Constructor Detail

Result

public Result(SqlNode node,
              Collection<SqlImplementor.Clause> clauses,
              String neededAlias,
              RelDataType neededType,
              Map<String,RelDataType> aliases)

Method Detail

builder

public SqlImplementor.Builder builder(RelNode rel,
                                      SqlImplementor.Clause... clauses)

Once you have a Result of implementing a child relational expression, call this method to create a Builder to implement the current relational expression by adding additional clauses to the SQL query.

You need to declare which clauses you intend to add. If the clauses are "later", you can add to the same query. For example, "GROUP BY" comes after "WHERE". But if they are the same or earlier, this method will start a new SELECT that wraps the previous result.

When you have called SqlImplementor.Builder.setSelect(SqlNodeList), SqlImplementor.Builder.setWhere(SqlNode) etc. call SqlImplementor.result(SqlNode, Collection, RelNode, Map) to fix the new query.

Parameters:

rel - Relational expression being implemented

clauses - Clauses that will be generated to implement current relational expression

Returns:

A builder

hasNestedAggregations

private boolean hasNestedAggregations(LogicalAggregate rel)

maxClause

public SqlImplementor.Clause maxClause()

asFrom

public SqlNode asFrom()

Returns a node that can be included in the FROM clause or a JOIN. It has an alias that is unique within the query. The alias is implicit if it can be derived using the usual rules (For example, "SELECT * FROM emp" is equivalent to "SELECT * FROM emp AS emp".)

subSelect

public SqlSelect subSelect()

asSelect

public SqlSelect asSelect()

Converts a non-query node into a SELECT node. Set operators (UNION, INTERSECT, EXCEPT) remain as is.

asStatement

public SqlNode asStatement()

Converts a non-query node into a SELECT node. Set operators (UNION, INTERSECT, EXCEPT) and DML operators (INSERT, UPDATE, DELETE, MERGE) remain as is.

asQueryOrValues

public SqlNode asQueryOrValues()

Converts a non-query node into a SELECT node. Set operators (UNION, INTERSECT, EXCEPT) and VALUES remain as is.

qualifiedContext

public SqlImplementor.Context qualifiedContext()

Returns a context that always qualifies identifiers. Useful if the Context deals with just one arm of a join, yet we wish to generate a join condition that qualifies column names to disambiguate them.

resetAlias

public SqlImplementor.Result resetAlias()

In join, when the left and right nodes have been generated, update their alias with 'neededAlias' if not null.