ValueNull (H2 Database Engine wt-1.0.1 API)

java.lang.Object
- org.h2.value.Value
- - org.h2.value.ValueNull

```
public class ValueNull
extends Value
```
Implementation of NULL. NULL is not a regular data type.

嵌套类概要
- 从类继承的嵌套类/接口 org.h2.value.Value
  Value.ValueBlob, Value.ValueClob

字段概要

字段
限定符和类型字段和说明

static ValueNull DELETED
This special instance is used as a marker for deleted entries in a map.

static ValueNull INSTANCE
The main NULL instance.
- 从类继承的字段 org.h2.value.Value
  ARRAY, BLOB, BOOLEAN, BYTE, BYTES, CLOB, DATE, DECIMAL, DOUBLE, FLOAT, GEOMETRY, INT, JAVA_OBJECT, LONG, NULL, RESULT_SET, SHORT, STRING, STRING_FIXED, STRING_IGNORECASE, TIME, TIMESTAMP, TIMESTAMP_TZ, TYPE_COUNT, UNKNOWN, UUID

字段
限定符和类型	字段和说明
`static ValueNull`	`DELETED` This special instance is used as a marker for deleted entries in a map.
`static ValueNull`	`INSTANCE` The main NULL instance.

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`protected int`	`compareSecure(Value v, CompareMode mode)` Compare the value with another value of the same type.
`Value`	`convertTo(int type)` Compare a value to the specified type.
`boolean`	`equals(Object other)` Check if the two values have the same hash code.
`BigDecimal`	`getBigDecimal()`
`Boolean`	`getBoolean()`
`byte`	`getByte()`
`byte[]`	`getBytes()`
`Date`	`getDate()`
`int`	`getDisplaySize()` Get the display size in characters.
`double`	`getDouble()`
`float`	`getFloat()`
`InputStream`	`getInputStream()`
`int`	`getInt()`
`long`	`getLong()`
`Object`	`getObject()` Get the value as an object.
`long`	`getPrecision()` Get the precision.
`Reader`	`getReader()`
`short`	`getShort()`
`String`	`getSQL()` Get the SQL expression for this value.
`String`	`getString()` Get the value as a string.
`Time`	`getTime()`
`Timestamp`	`getTimestamp()`
`int`	`getType()` Get the value type.
`int`	`hashCode()`
`void`	`set(PreparedStatement prep, int parameterIndex)` Set the value as a parameter in a prepared statement.

从类继承的方法 org.h2.value.Value
add, checkPrecision, clearCache, compareTo, compareTypeSafe, convertPrecision, convertScale, copy, copyToResult, copyToTemp, divide, getBytesNoCopy, getDataHandler, getHigherOrder, getMemory, getResultSet, getScale, getSignum, getSmall, getTableId, getTraceSQL, isLinkedToTable, modulus, multiply, negate, remove, subtract, throwUnsupportedExceptionForType, toString

从类继承的方法 java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- 字段详细资料
  - INSTANCE
```
public static final ValueNull INSTANCE
```
    The main NULL instance.
  - DELETED
```
public static final ValueNull DELETED
```
    This special instance is used as a marker for deleted entries in a map. It should not be used anywhere else.
- 方法详细资料
  - getSQL
```
public String getSQL()
```
    从类复制的说明: Value
    
    Get the SQL expression for this value.
    
    指定者:
    
    getSQL 在类中 Value
    
    返回:
    
    the SQL expression
  - getType
```
public int getType()
```
    从类复制的说明: Value
    
    Get the value type.
    
    指定者:
    
    getType 在类中 Value
    
    返回:
    
    the type
  - getString
```
public String getString()
```
    从类复制的说明: Value
    
    Get the value as a string.
    
    指定者:
    
    getString 在类中 Value
    
    返回:
    
    the string
  - getBoolean
```
public Boolean getBoolean()
```
    覆盖:
    
    getBoolean 在类中 Value
  - getDate
```
public Date getDate()
```
    覆盖:
    
    getDate 在类中 Value
  - getTime
```
public Time getTime()
```
    覆盖:
    
    getTime 在类中 Value
  - getTimestamp
```
public Timestamp getTimestamp()
```
    覆盖:
    
    getTimestamp 在类中 Value
  - getBytes
```
public byte[] getBytes()
```
    覆盖:
    
    getBytes 在类中 Value
  - getByte
```
public byte getByte()
```
    覆盖:
    
    getByte 在类中 Value
  - getShort
```
public short getShort()
```
    覆盖:
    
    getShort 在类中 Value
  - getBigDecimal
```
public BigDecimal getBigDecimal()
```
    覆盖:
    
    getBigDecimal 在类中 Value
  - getDouble
```
public double getDouble()
```
    覆盖:
    
    getDouble 在类中 Value
  - getFloat
```
public float getFloat()
```
    覆盖:
    
    getFloat 在类中 Value
  - getInt
```
public int getInt()
```
    覆盖:
    
    getInt 在类中 Value
  - getLong
```
public long getLong()
```
    覆盖:
    
    getLong 在类中 Value
  - getInputStream
```
public InputStream getInputStream()
```
    覆盖:
    
    getInputStream 在类中 Value
  - getReader
```
public Reader getReader()
```
    覆盖:
    
    getReader 在类中 Value
  - convertTo
```
public Value convertTo(int type)
```
    从类复制的说明: Value
    
    Compare a value to the specified type.
    
    覆盖:
    
    convertTo 在类中 Value
    
    参数:
    
    type - the type of the returned value
    
    返回:
    
    the converted value
  - compareSecure
```
protected int compareSecure(Value v,
                            CompareMode mode)
```
    从类复制的说明: Value
    
    Compare the value with another value of the same type.
    
    指定者:
    
    compareSecure 在类中 Value
    
    参数:
    
    v - the other value
    
    mode - the compare mode
    
    返回:
    
    0 if both values are equal, -1 if the other value is smaller, and 1 otherwise
  - getPrecision
```
public long getPrecision()
```
    从类复制的说明: Value
    
    Get the precision.
    
    指定者:
    
    getPrecision 在类中 Value
    
    返回:
    
    the precision
  - hashCode
```
public int hashCode()
```
    指定者:
    
    hashCode 在类中 Value
  - getObject
```
public Object getObject()
```
    从类复制的说明: Value
    
    Get the value as an object.
    
    指定者:
    
    getObject 在类中 Value
    
    返回:
    
    the object
  - set
```
public void set(PreparedStatement prep,
                int parameterIndex)
         throws SQLException
```
    从类复制的说明: Value
    
    Set the value as a parameter in a prepared statement.
    
    指定者:
    
    set 在类中 Value
    
    参数:
    
    prep - the prepared statement
    
    parameterIndex - the parameter index
    
    抛出:
    
    SQLException
  - getDisplaySize
```
public int getDisplaySize()
```
    从类复制的说明: Value
    
    Get the display size in characters.
    
    指定者:
    
    getDisplaySize 在类中 Value
    
    返回:
    
    the display size
  - equals
```
public boolean equals(Object other)
```
    从类复制的说明: Value
    
    Check if the two values have the same hash code. No data conversion is made; this method returns false if the other object is not of the same class. For some values, compareTo may return 0 even if equals return false. Example: ValueDecimal 0.0 and 0.00.
    
    指定者:
    
    equals 在类中 Value
    
    参数:
    
    other - the other value
    
    返回:
    
    true if they are equal

类 ValueNull

嵌套类概要

从类继承的嵌套类/接口 org.h2.value.Value

字段概要

从类继承的字段 org.h2.value.Value

方法概要

从类继承的方法 org.h2.value.Value

从类继承的方法 java.lang.Object

字段详细资料

INSTANCE

DELETED

方法详细资料

getSQL

getType

getString

getBoolean

getDate

getTime

getTimestamp

getBytes

getByte

getShort

getBigDecimal

getDouble

getFloat

getInt

getLong

getInputStream

getReader

convertTo

compareSecure

getPrecision

hashCode

getObject

set

getDisplaySize

equals