SqlToRelConverter.AggConverter (Flink : 2.0-preview1 API)

java.lang.Object
- org.apache.calcite.sql2rel.SqlToRelConverter.AggConverter

All Implemented Interfaces:

org.apache.calcite.sql.util.SqlVisitor<Void>

Enclosing class:

SqlToRelConverter
```
protected class SqlToRelConverter.AggConverter
extends Object
implements org.apache.calcite.sql.util.SqlVisitor<Void>
```
Converts expressions to aggregates.
Consider the expression
SELECT deptno, SUM(2 * sal) FROM emp GROUP BY deptno

Then:
- groupExprs = {SqlIdentifier(deptno)}
- convertedInputExprs = {RexInputRef(deptno), 2 * RefInputRef(sal)}
- inputRefs = {RefInputRef(#0), RexInputRef(#1)}
- aggCalls = {AggCall(SUM, {1})}

Field Summary

Fields
Modifier and Type Field Description

@Nullable org.apache.calcite.sql.validate.AggregatingSelectScope aggregatingSelectScope

Constructor Summary

Constructors
Constructor Description

AggConverter(SqlToRelConverter.Blackboard bb, org.apache.calcite.sql.SqlSelect select)
Creates an AggConverter.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`addGroupExpr(org.apache.calcite.sql.SqlNode expr)`
`List<org.apache.calcite.rel.core.AggregateCall>`	`getAggCalls()`
`List<org.apache.calcite.util.Pair<org.apache.calcite.rex.RexNode,@Nullable String>>`	`getPreExprs()`
`org.apache.calcite.rel.type.RelDataTypeFactory`	`getTypeFactory()`
`@Nullable org.apache.calcite.rex.RexNode`	`lookupAggregates(org.apache.calcite.sql.SqlCall call)`
`int`	`lookupGroupExpr(org.apache.calcite.sql.SqlNode expr)`	If an expression is structurally identical to one of the group-by expressions, returns a reference to the expression, otherwise returns null.
`Void`	`visit(org.apache.calcite.sql.SqlCall call)`
`Void`	`visit(org.apache.calcite.sql.SqlDataTypeSpec type)`
`Void`	`visit(org.apache.calcite.sql.SqlDynamicParam param)`
`Void`	`visit(org.apache.calcite.sql.SqlIdentifier id)`
`Void`	`visit(org.apache.calcite.sql.SqlIntervalQualifier intervalQualifier)`
`Void`	`visit(org.apache.calcite.sql.SqlLiteral lit)`
`Void`	`visit(org.apache.calcite.sql.SqlNodeList nodeList)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

aggregatingSelectScope

public final @Nullable org.apache.calcite.sql.validate.AggregatingSelectScope aggregatingSelectScope

Constructor Detail
- AggConverter
```
public AggConverter(SqlToRelConverter.Blackboard bb,
                    org.apache.calcite.sql.SqlSelect select)
```
  Creates an AggConverter.
  The select parameter provides enough context to name aggregate calls which are top-level select list items.
  
  Parameters:
  
  bb - Blackboard
  
  select - Query being translated; provides context to give

Method Detail

addGroupExpr

public int addGroupExpr(org.apache.calcite.sql.SqlNode expr)

visit
```
public Void visit(org.apache.calcite.sql.SqlIdentifier id)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit
```
public Void visit(org.apache.calcite.sql.SqlNodeList nodeList)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit
```
public Void visit(org.apache.calcite.sql.SqlLiteral lit)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit
```
public Void visit(org.apache.calcite.sql.SqlDataTypeSpec type)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit
```
public Void visit(org.apache.calcite.sql.SqlDynamicParam param)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit

public Void visit(org.apache.calcite.sql.SqlIntervalQualifier intervalQualifier)

Specified by:: visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

visit
```
public Void visit(org.apache.calcite.sql.SqlCall call)
```
Specified by:

visit in interface org.apache.calcite.sql.util.SqlVisitor<Void>

lookupGroupExpr
```
public int lookupGroupExpr(org.apache.calcite.sql.SqlNode expr)
```
If an expression is structurally identical to one of the group-by expressions, returns a reference to the expression, otherwise returns null.

lookupAggregates

public @Nullable org.apache.calcite.rex.RexNode lookupAggregates(org.apache.calcite.sql.SqlCall call)

getPreExprs

public List<org.apache.calcite.util.Pair<org.apache.calcite.rex.RexNode,@Nullable String>> getPreExprs()

getAggCalls

public List<org.apache.calcite.rel.core.AggregateCall> getAggCalls()

getTypeFactory

public org.apache.calcite.rel.type.RelDataTypeFactory getTypeFactory()