TransformSqlReturnTypes (flink-cdc-runtime 3.3.0 API)

```
public class TransformSqlReturnTypes
extends Object
```
This is the return type definition of the call in the Transform expression, which references the class of FlinkReturnTypes in the Flink. In addition, its difference is that it is specifically referenced for FlinkCDC's Transform, and there may be new extensions here in the future.

字段
限定符和类型	字段和说明
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`ARG0_VARCHAR_FORCE_NULLABLE` Type-inference strategy whereby the result type of a call is the type of the operand #0 (0-based), with nulls always allowed.
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`ARG2_TIMESTAMP_FORCE_NULLABLE`
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`IF_NULLABLE` Determine the return type of IF functions with arguments that has the least restrictive (eg: numeric, character, binary).
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`NUMERIC_FROM_ARG1_DEFAULT1`
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`NUMERIC_FROM_ARG1_DEFAULT1_NULLABLE`
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`ROUND_FUNCTION` ROUND(num [,len]) type inference.
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`ROUND_FUNCTION_NULLABLE`
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`VARCHAR_FORCE_NULLABLE`
`static org.apache.calcite.sql.type.SqlReturnTypeInference`	`VARCHAR_NOT_NULL`

构造器
构造器和说明
`TransformSqlReturnTypes()`

public static final org.apache.calcite.sql.type.SqlReturnTypeInference ROUND_FUNCTION

ROUND(num [,len]) type inference.

ARG0_VARCHAR_FORCE_NULLABLE
```
public static final org.apache.calcite.sql.type.SqlReturnTypeInference ARG0_VARCHAR_FORCE_NULLABLE
```
Type-inference strategy whereby the result type of a call is the type of the operand #0 (0-based), with nulls always allowed.

public static final org.apache.calcite.sql.type.SqlReturnTypeInference VARCHAR_FORCE_NULLABLE

public static final org.apache.calcite.sql.type.SqlReturnTypeInference VARCHAR_NOT_NULL

public static final org.apache.calcite.sql.type.SqlReturnTypeInference ROUND_FUNCTION_NULLABLE

IF_NULLABLE
```
public static final org.apache.calcite.sql.type.SqlReturnTypeInference IF_NULLABLE
```
Determine the return type of IF functions with arguments that has the least restrictive (eg: numeric, character, binary). The return type is the type of the argument with the largest range. We start to consider the arguments from the first one. If one of the arguments is not of the type that has the least restrictive (eg: numeric, character, binary), we return the type of the first argument instead.

public static final org.apache.calcite.sql.type.SqlReturnTypeInference NUMERIC_FROM_ARG1_DEFAULT1

public static final org.apache.calcite.sql.type.SqlReturnTypeInference NUMERIC_FROM_ARG1_DEFAULT1_NULLABLE

public static final org.apache.calcite.sql.type.SqlReturnTypeInference ARG2_TIMESTAMP_FORCE_NULLABLE

类 TransformSqlReturnTypes