org.apache.calcite.rel.rel2sql

Class SqlImplementor

java.lang.Object

org.apache.calcite.rel.rel2sql.SqlImplementor

Direct Known Subclasses:

RelToSqlConverter

public abstract class SqlImplementor
extends Object

State for generating a SQL statement.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	SqlImplementor.AliasContext Implementation of Context that precedes field references with their "table alias" based on the current sub-query's FROM clause.
protected class	SqlImplementor.BaseContext Implementation of SqlImplementor.Context that has an enclosing SqlImplementor and can therefore do non-trivial expressions.
class	SqlImplementor.Builder Builder.
static class	SqlImplementor.Clause Clauses in a SQL query.
static class	SqlImplementor.Context Context for translating a RexNode expression (within a RelNode) into a SqlNode expression (within a SQL parse tree).
class	SqlImplementor.MatchRecognizeContext Context for translating MATCH_RECOGNIZE clause.
class	SqlImplementor.Result Result of implementing a node.
static class	SqlImplementor.SimpleContext Simple implementation of SqlImplementor.Context that cannot handle sub-queries or correlations.

Field Summary

Fields

Modifier and Type	Field and Description
protected Set<String>	aliasSet
protected Map<CorrelationId,SqlImplementor.Context>	correlTableMap
SqlDialect	dialect
static SqlParserPos	POS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SqlImplementor(SqlDialect dialect)

Method Summary

Modifier and Type	Method and Description
void	addSelect(List<SqlNode> selectList, SqlNode node, RelDataType rowType)
SqlImplementor.Context	aliasContext(Map<String,RelDataType> aliases, boolean qualified)
protected SqlCall	as(SqlNode e, String alias, String... fieldNames) Convenience method for creating column and table aliases.
static SqlNode	convertConditionToSqlNode(RexNode node, SqlImplementor.Context leftContext, SqlImplementor.Context rightContext) Converts a RexNode condition into a SqlNode.
protected boolean	isAnon() Returns whether to remove trivial aliases such as "EXPR$0" when converting the current relational expression into a SELECT.
static boolean	isStar(List<RexNode> exps, RelDataType inputRowType, RelDataType projectRowType) Returns whether a list of expressions projects all fields, in order, from the input, with the same names.
static boolean	isStar(RexProgram program)
SqlImplementor.Context	joinContext(SqlImplementor.Context leftContext, SqlImplementor.Context rightContext)
static JoinType	joinType(JoinRelType joinType)
SqlImplementor.Context	matchRecognizeContext(SqlImplementor.Context context)
SqlImplementor.Result	result(SqlNode node, Collection<SqlImplementor.Clause> clauses, RelNode rel, @Nullable Map<String,RelDataType> aliases) Creates a result based on a single relational expression.
protected SqlImplementor.Result	result(SqlNode node, Collection<SqlImplementor.Clause> clauses, @Nullable String neededAlias, @Nullable RelDataType neededType, Map<String,RelDataType> aliases) Factory method for SqlImplementor.Result.
SqlImplementor.Result	result(SqlNode join, SqlImplementor.Result leftResult, SqlImplementor.Result rightResult) Creates a result based on a join.
SqlImplementor.Result	setOpToSql(SqlSetOperator operator, RelNode rel)
SqlImplementor.Context	tableFunctionScanContext(List<SqlNode> inputSqlNodes)
static SqlNode	toSql(RexLiteral literal) Converts a RexLiteral to a SqlLiteral.
static SqlNode	toSql(@Nullable RexProgram program, RexLiteral literal) Converts a RexLiteral in the context of a RexProgram to a SqlNode.
SqlImplementor.Result	visitChild(int i, RelNode e) Deprecated. Use either visitRoot(RelNode) or visitInput(RelNode, int).
SqlImplementor.Result	visitInput(RelNode e, int i) Visits an input of the current relational expression, deducing anon using isAnon().
abstract SqlImplementor.Result	visitInput(RelNode e, int i, boolean anon, boolean ignoreClauses, Set<SqlImplementor.Clause> expectedClauses) Visits the ith input of e, the current relational expression.
SqlImplementor.Result	visitInput(RelNode e, int i, Set<SqlImplementor.Clause> clauses) Visits an input of the current relational expression, deducing anon using isAnon().
SqlImplementor.Result	visitInput(RelNode e, int i, SqlImplementor.Clause... clauses) Visits an input of the current relational expression, with the given expected clauses.
SqlImplementor.Result	visitRoot(RelNode r) Visits a relational expression that has no parent.

Methods inherited from class java.lang.Object

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

Field Detail

POS

public static final SqlParserPos POS

dialect

public final SqlDialect dialect

aliasSet

protected final Set<String> aliasSet

correlTableMap

protected final Map<CorrelationId,SqlImplementor.Context> correlTableMap

Constructor Detail

SqlImplementor

protected SqlImplementor(SqlDialect dialect)

Method Detail

visitRoot

public final SqlImplementor.Result visitRoot(RelNode r)

Visits a relational expression that has no parent.

visitChild

@Deprecated
public final SqlImplementor.Result visitChild(int i,
                                                          RelNode e)

Deprecated. Use either visitRoot(RelNode) or visitInput(RelNode, int).

visitInput

public final SqlImplementor.Result visitInput(RelNode e,
                                              int i)

Visits an input of the current relational expression, deducing anon using isAnon().

visitInput

public final SqlImplementor.Result visitInput(RelNode e,
                                              int i,
                                              SqlImplementor.Clause... clauses)

Visits an input of the current relational expression, with the given expected clauses.

visitInput

public final SqlImplementor.Result visitInput(RelNode e,
                                              int i,
                                              Set<SqlImplementor.Clause> clauses)

Visits an input of the current relational expression, deducing anon using isAnon().

visitInput

public abstract SqlImplementor.Result visitInput(RelNode e,
                                                 int i,
                                                 boolean anon,
                                                 boolean ignoreClauses,
                                                 Set<SqlImplementor.Clause> expectedClauses)

Visits the ith input of e, the current relational expression.

Parameters:

e - Current relational expression

i - Ordinal of input within e

anon - Whether to remove trivial aliases such as "EXPR$0"

ignoreClauses - Whether to ignore the expected clauses when deciding whether a sub-query is required

expectedClauses - Set of clauses that we expect the builder that consumes this result will create

Returns:

Result

See Also:

isAnon()

addSelect

public void addSelect(List<SqlNode> selectList,
                      SqlNode node,
                      RelDataType rowType)

as

protected SqlCall as(SqlNode e,
                     String alias,
                     String... fieldNames)

Convenience method for creating column and table aliases.

AS(e, "c") creates "e AS c"; AS(e, "t", "c1", "c2" creates "e AS t (c1, c2)".

isStar

public static boolean isStar(List<RexNode> exps,
                             RelDataType inputRowType,
                             RelDataType projectRowType)

Returns whether a list of expressions projects all fields, in order, from the input, with the same names.

isStar

public static boolean isStar(RexProgram program)

setOpToSql

public SqlImplementor.Result setOpToSql(SqlSetOperator operator,
                                        RelNode rel)

convertConditionToSqlNode

public static SqlNode convertConditionToSqlNode(RexNode node,
                                                SqlImplementor.Context leftContext,
                                                SqlImplementor.Context rightContext)

Converts a RexNode condition into a SqlNode.

Parameters:

node - Join condition

leftContext - Left context

rightContext - Right context

Returns:

SqlNode that represents the condition

joinType

public static JoinType joinType(JoinRelType joinType)

result

public SqlImplementor.Result result(SqlNode node,
                                    Collection<SqlImplementor.Clause> clauses,
                                    RelNode rel,
                                    @Nullable Map<String,RelDataType> aliases)

Creates a result based on a single relational expression.

result

protected SqlImplementor.Result result(SqlNode node,
                                       Collection<SqlImplementor.Clause> clauses,
                                       @Nullable String neededAlias,
                                       @Nullable RelDataType neededType,
                                       Map<String,RelDataType> aliases)

Factory method for SqlImplementor.Result.

Call this method rather than creating a Result directly, because sub-classes may override.

result

public SqlImplementor.Result result(SqlNode join,
                                    SqlImplementor.Result leftResult,
                                    SqlImplementor.Result rightResult)

Creates a result based on a join. (Each join could contain one or more relational expressions.)

isAnon

protected boolean isAnon()

Returns whether to remove trivial aliases such as "EXPR$0" when converting the current relational expression into a SELECT.

For example, INSERT does not care about field names; we would prefer to generate without the "EXPR$0" alias:

 INSERT INTO t1 SELECT x, y + 1 FROM t2

rather than with it:

 INSERT INTO t1 SELECT x, y + 1 AS EXPR$0 FROM t2

But JOIN does care about field names; we have to generate the "EXPR$0" alias:

 SELECT *
 FROM emp AS e
 JOIN (SELECT x, y + 1 AS EXPR$0) AS d
 ON e.deptno = d.EXPR$0
 

because if we omit "AS EXPR$0" we do not know the field we are joining to, and the following is invalid:

 SELECT *
 FROM emp AS e
 JOIN (SELECT x, y + 1) AS d
 ON e.deptno = d.EXPR$0
 

toSql

public static SqlNode toSql(@Nullable RexProgram program,
                            RexLiteral literal)

Converts a RexLiteral in the context of a RexProgram to a SqlNode.

toSql

public static SqlNode toSql(RexLiteral literal)

Converts a RexLiteral to a SqlLiteral.

aliasContext

public SqlImplementor.Context aliasContext(Map<String,RelDataType> aliases,
                                           boolean qualified)

joinContext

public SqlImplementor.Context joinContext(SqlImplementor.Context leftContext,
                                          SqlImplementor.Context rightContext)

matchRecognizeContext

public SqlImplementor.Context matchRecognizeContext(SqlImplementor.Context context)

tableFunctionScanContext

public SqlImplementor.Context tableFunctionScanContext(List<SqlNode> inputSqlNodes)