org.apache.calcite.adapter.jdbc

Class JdbcImplementor.Result

java.lang.Object

org.apache.calcite.adapter.jdbc.JdbcImplementor.Result

Enclosing class:

JdbcImplementor

public class JdbcImplementor.Result
extends Object

Result of implementing a node.

Method Summary

Methods

Modifier and Type	Method and Description
SqlNode	asFrom() Returns a node that can be included in the FROM clause or a JOIN.
SqlNode	asQuery() Converts a non-query node into a SELECT node.
JdbcImplementor.Builder	builder(JdbcRel rel, org.apache.calcite.adapter.jdbc.JdbcImplementor.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.
org.apache.calcite.adapter.jdbc.JdbcImplementor.Clause	maxClause()
JdbcImplementor.Context	qualifiedContext() Returns a context that always qualifies identifiers.
SqlSelect	subSelect()

Methods inherited from class java.lang.Object

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

Method Detail

builder

public JdbcImplementor.Builder builder(JdbcRel rel,
                              org.apache.calcite.adapter.jdbc.JdbcImplementor.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 JdbcImplementor.Builder.setSelect(org.apache.calcite.sql.SqlNodeList), JdbcImplementor.Builder.setWhere(org.apache.calcite.sql.SqlNode) etc. call JdbcImplementor.result(org.apache.calcite.sql.SqlNode, java.util.Collection, org.apache.calcite.rel.RelNode) 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

maxClause

public org.apache.calcite.adapter.jdbc.JdbcImplementor.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()

asQuery

public SqlNode asQuery()

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

qualifiedContext

public JdbcImplementor.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.