InferTypes (Apache Calcite API)

java.lang.Object
- org.apache.calcite.sql.type.InferTypes

```
public abstract class InferTypes
extends java.lang.Object
```
Strategies for inferring operand types.

See Also:

SqlOperandTypeInference, ReturnTypes

Field Summary

Fields
Modifier and Type	Field	Description
`static SqlOperandTypeInference`	`BOOLEAN`	Operand type-inference strategy where an unknown operand type is assumed to be boolean.
`static SqlOperandTypeInference`	`FIRST_KNOWN`	Operand type-inference strategy where an unknown operand type is derived from the first operand with a known type.
`static SqlOperandTypeInference`	`RETURN_TYPE`	Operand type-inference strategy where an unknown operand type is derived from the call's return type.
`static SqlOperandTypeInference`	`VARCHAR_1024`	Operand type-inference strategy where an unknown operand type is assumed to be VARCHAR(1024).

Constructor Summary

Constructors
Modifier Constructor Description

private InferTypes()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static SqlOperandTypeInference`	`explicit(java.util.List<RelDataType> types)`	Returns an `SqlOperandTypeInference` that returns a given list of types.

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

- Field Detail
  - FIRST_KNOWN
```
public static final SqlOperandTypeInference FIRST_KNOWN
```
    Operand type-inference strategy where an unknown operand type is derived from the first operand with a known type.
  - RETURN_TYPE
```
public static final SqlOperandTypeInference RETURN_TYPE
```
    Operand type-inference strategy where an unknown operand type is derived from the call's return type. If the return type is a record, it must have the same number of fields as the number of operands.
  - BOOLEAN
```
public static final SqlOperandTypeInference BOOLEAN
```
    Operand type-inference strategy where an unknown operand type is assumed to be boolean.
  - VARCHAR_1024
```
public static final SqlOperandTypeInference VARCHAR_1024
```
    Operand type-inference strategy where an unknown operand type is assumed to be VARCHAR(1024). This is not something which should be used in most cases (especially since the precision is arbitrary), but for IS [NOT] NULL, we don't really care about the type at all, so it's reasonable to use something that every other type can be cast to.
- Constructor Detail
  - InferTypes
```
private InferTypes()
```
- Method Detail
  - explicit
```
public static SqlOperandTypeInference explicit(java.util.List<RelDataType> types)
```
    Returns an SqlOperandTypeInference that returns a given list of types.