SqlExtendOperator (Apache Calcite API)

java.lang.Object
- org.apache.calcite.sql.SqlOperator
- - org.apache.calcite.sql.SqlSpecialOperator
  - - org.apache.calcite.sql.SqlInternalOperator
    - - org.apache.calcite.sql.fun.SqlExtendOperator

```
class SqlExtendOperator
extends SqlInternalOperator
```
EXTEND operator.
Adds columns to a table's schema, as in SELECT ... FROM emp EXTEND (horoscope VARCHAR(100)).
Not standard SQL. Added to Calcite to support Phoenix, but can be used to achieve schema-on-query against other adapters.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.calcite.sql.SqlSpecialOperator
  SqlSpecialOperator.ReduceResult, SqlSpecialOperator.TokenSequence

Field Summary
- Fields inherited from class org.apache.calcite.sql.SqlOperator
  kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors
Constructor Description

SqlExtendOperator()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`unparse(SqlWriter writer, SqlCall call, int leftPrec, int rightPrec)`	Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.

Methods inherited from class org.apache.calcite.sql.SqlInternalOperator
deriveType, getSyntax

Methods inherited from class org.apache.calcite.sql.SqlSpecialOperator
reduceExpr

Methods inherited from class org.apache.calcite.sql.SqlOperator
acceptCall, acceptCall, adjustType, allowsFraming, argumentMustBeScalar, checkOperandCount, checkOperandTypes, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getNameAsId, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, leftPrec, preValidateCall, requiresDecimalExpansion, requiresOrder, requiresOver, rewriteCall, rightPrec, toString, unparseListClause, unparseListClause, validateCall, validateOperands, validRexOperands

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

- Constructor Detail
  - SqlExtendOperator
```
SqlExtendOperator()
```
- Method Detail
  - unparse
```
public void unparse(SqlWriter writer,
                    SqlCall call,
                    int leftPrec,
                    int rightPrec)
```
    Description copied from class: SqlOperator
    
    Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.
    The default implementation of this method delegates to SqlSyntax.unparse(org.apache.calcite.sql.SqlWriter, org.apache.calcite.sql.SqlOperator, org.apache.calcite.sql.SqlCall, int, int).
    
    Overrides:
    
    unparse in class SqlOperator