Value (H2 Database Engine wt-1.0.1 API)

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

直接已知子类:

ValueArray, ValueBoolean, ValueByte, ValueBytes, ValueDate, ValueDecimal, ValueDouble, ValueFloat, ValueGeometry, ValueInt, ValueLob, ValueLobDb, ValueLong, ValueNull, ValueResultSet, ValueShort, ValueString, ValueTime, ValueTimestamp, ValueTimestampTimeZone, ValueUuid
```
public abstract class Value
extends Object
```
This is the base class for all value classes. It provides conversion and comparison methods.

作者:

Thomas Mueller, Noel Grandin, Nicolas Fortin, Atelier SIG, IRSTV FR CNRS 24888

嵌套类概要

嵌套类
限定符和类型类和说明

static interface Value.ValueBlob
A "character large object".

static interface Value.ValueClob
A "binary large object".

嵌套类
限定符和类型	类和说明
`static interface`	`Value.ValueBlob` A "character large object".
`static interface`	`Value.ValueClob` A "binary large object".

字段概要

字段
限定符和类型	字段和说明
`static int`	`ARRAY` The value type for ARRAY values.
`static int`	`BLOB` The value type for BLOB values.
`static int`	`BOOLEAN` The value type for BOOLEAN values.
`static int`	`BYTE` The value type for BYTE values.
`static int`	`BYTES` The value type for BYTES values.
`static int`	`CLOB` The value type for CLOB values.
`static int`	`DATE` The value type for DATE values.
`static int`	`DECIMAL` The value type for DECIMAL values.
`static int`	`DOUBLE` The value type for DOUBLE values.
`static int`	`FLOAT` The value type for FLOAT values.
`static int`	`GEOMETRY` The value type for string values with a fixed size.
`static int`	`INT` The value type for INT values.
`static int`	`JAVA_OBJECT` The value type for JAVA_OBJECT values.
`static int`	`LONG` The value type for LONG values.
`static int`	`NULL` The value type for NULL.
`static int`	`RESULT_SET` The value type for RESULT_SET values.
`static int`	`SHORT` The value type for SHORT values.
`static int`	`STRING` The value type for STRING values.
`static int`	`STRING_FIXED` The value type for string values with a fixed size.
`static int`	`STRING_IGNORECASE` The value type for case insensitive STRING values.
`static int`	`TIME` The value type for TIME values.
`static int`	`TIMESTAMP` The value type for TIMESTAMP values.
`static int`	`TIMESTAMP_TZ` The value type for TIMESTAMP WITH TIMEZONE values.
`static int`	`TYPE_COUNT` The number of value types.
`static int`	`UNKNOWN` The data type is unknown at this time.
`static int`	`UUID` The value type for UUID values.

构造器概要

构造器
构造器和说明

Value()

构造器
构造器和说明
`Value()`

方法概要

所有方法静态方法实例方法抽象方法具体方法
限定符和类型	方法和说明
`Value`	`add(Value v)` Add a value and return the result.
`boolean`	`checkPrecision(long precision)` Check if the precision is smaller or equal than the given precision.
`static void`	`clearCache()` Clear the value cache.
`protected abstract int`	`compareSecure(Value v, CompareMode mode)` Compare the value with another value of the same type.
`int`	`compareTo(Value v, CompareMode mode)` Compare this value against another value using the specified compare mode.
`int`	`compareTypeSafe(Value v, CompareMode mode)` Compare this value against another value given that the values are of the same data type.
`Value`	`convertPrecision(long precision, boolean force)` Convert the precision to the requested value.
`Value`	`convertScale(boolean onlyToSmallerScale, int targetScale)` Convert the scale.
`Value`	`convertTo(int targetType)` Compare a value to the specified type.
`Value`	`copy(DataHandler handler, int tableId)` Copy a large value, to be used in the given table.
`Value`	`copyToResult()` Create an independent copy of this value if needed, that will be bound to a result.
`Value`	`copyToTemp()` Copy this value to a temporary file if necessary.
`Value`	`divide(Value v)` Divide by a value and return the result.
`abstract boolean`	`equals(Object other)` Check if the two values have the same hash code.
`BigDecimal`	`getBigDecimal()`
`Boolean`	`getBoolean()`
`byte`	`getByte()`
`byte[]`	`getBytes()`
`byte[]`	`getBytesNoCopy()`
`protected DataHandler`	`getDataHandler()` Return the data handler for the values that support it (actually only Java objects).
`Date`	`getDate()`
`abstract int`	`getDisplaySize()` Get the display size in characters.
`double`	`getDouble()`
`float`	`getFloat()`
`static int`	`getHigherOrder(int t1, int t2)` Get the higher value order type of two value types.
`InputStream`	`getInputStream()`
`int`	`getInt()`
`long`	`getLong()`
`int`	`getMemory()` Get the memory used by this object.
`abstract Object`	`getObject()` Get the value as an object.
`abstract long`	`getPrecision()` Get the precision.
`Reader`	`getReader()`
`ResultSet`	`getResultSet()`
`int`	`getScale()`
`short`	`getShort()`
`int`	`getSignum()`
`byte[]`	`getSmall()` Get the byte array.
`abstract String`	`getSQL()` Get the SQL expression for this value.
`abstract String`	`getString()` Get the value as a string.
`int`	`getTableId()` Get the table (only for LOB object).
`Time`	`getTime()`
`Timestamp`	`getTimestamp()`
`String`	`getTraceSQL()` Get a medium size SQL expression for debugging or tracing.
`abstract int`	`getType()` Get the value type.
`abstract int`	`hashCode()`
`boolean`	`isLinkedToTable()` Check if this value is linked to a specific table.
`Value`	`modulus(Value v)` Take the modulus with a value and return the result.
`Value`	`multiply(Value v)` Multiply with a value and return the result.
`Value`	`negate()` Return -value if this value support arithmetic operations.
`void`	`remove()` Remove the underlying resource, if any.
`abstract void`	`set(PreparedStatement prep, int parameterIndex)` Set the value as a parameter in a prepared statement.
`Value`	`subtract(Value v)` Subtract a value and return the result.
`protected DbException`	`throwUnsupportedExceptionForType(String op)` Throw the exception that the feature is not support for the given data type.
`String`	`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
  - UNKNOWN
```
public static final int UNKNOWN
```
    The data type is unknown at this time.
    
    另请参阅:
    
    常量字段值
  - NULL
```
public static final int NULL
```
    The value type for NULL.
    
    另请参阅:
    
    常量字段值
  - BOOLEAN
```
public static final int BOOLEAN
```
    The value type for BOOLEAN values.
    
    另请参阅:
    
    常量字段值
  - BYTE
```
public static final int BYTE
```
    The value type for BYTE values.
    
    另请参阅:
    
    常量字段值
  - SHORT
```
public static final int SHORT
```
    The value type for SHORT values.
    
    另请参阅:
    
    常量字段值
  - INT
```
public static final int INT
```
    The value type for INT values.
    
    另请参阅:
    
    常量字段值
  - LONG
```
public static final int LONG
```
    The value type for LONG values.
    
    另请参阅:
    
    常量字段值
  - DECIMAL
```
public static final int DECIMAL
```
    The value type for DECIMAL values.
    
    另请参阅:
    
    常量字段值
  - DOUBLE
```
public static final int DOUBLE
```
    The value type for DOUBLE values.
    
    另请参阅:
    
    常量字段值
  - FLOAT
```
public static final int FLOAT
```
    The value type for FLOAT values.
    
    另请参阅:
    
    常量字段值
  - TIME
```
public static final int TIME
```
    The value type for TIME values.
    
    另请参阅:
    
    常量字段值
  - DATE
```
public static final int DATE
```
    The value type for DATE values.
    
    另请参阅:
    
    常量字段值
  - TIMESTAMP
```
public static final int TIMESTAMP
```
    The value type for TIMESTAMP values.
    
    另请参阅:
    
    常量字段值
  - BYTES
```
public static final int BYTES
```
    The value type for BYTES values.
    
    另请参阅:
    
    常量字段值
  - STRING
```
public static final int STRING
```
    The value type for STRING values.
    
    另请参阅:
    
    常量字段值
  - STRING_IGNORECASE
```
public static final int STRING_IGNORECASE
```
    The value type for case insensitive STRING values.
    
    另请参阅:
    
    常量字段值
  - BLOB
```
public static final int BLOB
```
    The value type for BLOB values.
    
    另请参阅:
    
    常量字段值
  - CLOB
```
public static final int CLOB
```
    The value type for CLOB values.
    
    另请参阅:
    
    常量字段值
  - ARRAY
```
public static final int ARRAY
```
    The value type for ARRAY values.
    
    另请参阅:
    
    常量字段值
  - RESULT_SET
```
public static final int RESULT_SET
```
    The value type for RESULT_SET values.
    
    另请参阅:
    
    常量字段值
  - JAVA_OBJECT
```
public static final int JAVA_OBJECT
```
    The value type for JAVA_OBJECT values.
    
    另请参阅:
    
    常量字段值
  - UUID
```
public static final int UUID
```
    The value type for UUID values.
    
    另请参阅:
    
    常量字段值
  - STRING_FIXED
```
public static final int STRING_FIXED
```
    The value type for string values with a fixed size.
    
    另请参阅:
    
    常量字段值
  - GEOMETRY
```
public static final int GEOMETRY
```
    The value type for string values with a fixed size.
    
    另请参阅:
    
    常量字段值
  - TIMESTAMP_TZ
```
public static final int TIMESTAMP_TZ
```
    The value type for TIMESTAMP WITH TIMEZONE values.
    
    另请参阅:
    
    常量字段值
  - TYPE_COUNT
```
public static final int TYPE_COUNT
```
    The number of value types.
    
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - Value
```
public Value()
```
- 方法详细资料
  - getSQL
```
public abstract String getSQL()
```
    Get the SQL expression for this value.
    
    返回:
    
    the SQL expression
  - getType
```
public abstract int getType()
```
    Get the value type.
    
    返回:
    
    the type
  - getPrecision
```
public abstract long getPrecision()
```
    Get the precision.
    
    返回:
    
    the precision
  - getDisplaySize
```
public abstract int getDisplaySize()
```
    Get the display size in characters.
    
    返回:
    
    the display size
  - getMemory
```
public int getMemory()
```
    Get the memory used by this object.
    
    返回:
    
    the memory used in bytes
  - getString
```
public abstract String getString()
```
    Get the value as a string.
    
    返回:
    
    the string
  - getObject
```
public abstract Object getObject()
```
    Get the value as an object.
    
    返回:
    
    the object
  - set
```
public abstract void set(PreparedStatement prep,
                         int parameterIndex)
                  throws SQLException
```
    Set the value as a parameter in a prepared statement.
    
    参数:
    
    prep - the prepared statement
    
    parameterIndex - the parameter index
    
    抛出:
    
    SQLException
  - compareSecure
```
protected abstract int compareSecure(Value v,
                                     CompareMode mode)
```
    Compare the value with another value of the same type.
    
    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
  - hashCode
```
public abstract int hashCode()
```
    覆盖:
    
    hashCode 在类中 Object
  - equals
```
public abstract boolean equals(Object other)
```
    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.
    
    覆盖:
    
    equals 在类中 Object
    
    参数:
    
    other - the other value
    
    返回:
    
    true if they are equal
  - getHigherOrder
```
public static int getHigherOrder(int t1,
                                 int t2)
```
    Get the higher value order type of two value types. If values need to be converted to match the other operands value type, the value with the lower order is converted to the value with the higher order.
    
    参数:
    
    t1 - the first value type
    
    t2 - the second value type
    
    返回:
    
    the higher value type of the two
  - clearCache
```
public static void clearCache()
```
    Clear the value cache. Used for testing.
  - getBoolean
```
public Boolean getBoolean()
```
  - getDate
```
public Date getDate()
```
  - getTime
```
public Time getTime()
```
  - getTimestamp
```
public Timestamp getTimestamp()
```
  - getBytes
```
public byte[] getBytes()
```
  - getBytesNoCopy
```
public byte[] getBytesNoCopy()
```
  - getByte
```
public byte getByte()
```
  - getShort
```
public short getShort()
```
  - getBigDecimal
```
public BigDecimal getBigDecimal()
```
  - getDouble
```
public double getDouble()
```
  - getFloat
```
public float getFloat()
```
  - getInt
```
public int getInt()
```
  - getLong
```
public long getLong()
```
  - getInputStream
```
public InputStream getInputStream()
```
  - getReader
```
public Reader getReader()
```
  - add
```
public Value add(Value v)
```
    Add a value and return the result.
    
    参数:
    
    v - the value to add
    
    返回:
    
    the result
  - getSignum
```
public int getSignum()
```
  - negate
```
public Value negate()
```
    Return -value if this value support arithmetic operations.
    
    返回:
    
    the negative
  - subtract
```
public Value subtract(Value v)
```
    Subtract a value and return the result.
    
    参数:
    
    v - the value to subtract
    
    返回:
    
    the result
  - divide
```
public Value divide(Value v)
```
    Divide by a value and return the result.
    
    参数:
    
    v - the value to divide by
    
    返回:
    
    the result
  - multiply
```
public Value multiply(Value v)
```
    Multiply with a value and return the result.
    
    参数:
    
    v - the value to multiply with
    
    返回:
    
    the result
  - modulus
```
public Value modulus(Value v)
```
    Take the modulus with a value and return the result.
    
    参数:
    
    v - the value to take the modulus with
    
    返回:
    
    the result
  - convertTo
```
public Value convertTo(int targetType)
```
    Compare a value to the specified type.
    
    参数:
    
    targetType - the type of the returned value
    
    返回:
    
    the converted value
  - compareTypeSafe
```
public final int compareTypeSafe(Value v,
                                 CompareMode mode)
```
    Compare this value against another value given that the values are of the same data type.
    
    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
  - compareTo
```
public final int compareTo(Value v,
                           CompareMode mode)
```
    Compare this value against another value using the specified compare mode.
    
    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
  - getScale
```
public int getScale()
```
  - convertScale
```
public Value convertScale(boolean onlyToSmallerScale,
                          int targetScale)
```
    Convert the scale.
    
    参数:
    
    onlyToSmallerScale - if the scale should not reduced
    
    targetScale - the requested scale
    
    返回:
    
    the value
  - convertPrecision
```
public Value convertPrecision(long precision,
                              boolean force)
```
    Convert the precision to the requested value. The precision of the returned value may be somewhat larger than requested, because values with a fixed precision are not truncated.
    
    参数:
    
    precision - the new precision
    
    force - true if losing numeric precision is allowed
    
    返回:
    
    the new value
  - copy
```
public Value copy(DataHandler handler,
                  int tableId)
```
    Copy a large value, to be used in the given table. For values that are kept fully in memory this method has no effect.
    
    参数:
    
    handler - the data handler
    
    tableId - the table where this object is used
    
    返回:
    
    the new value or itself
  - isLinkedToTable
```
public boolean isLinkedToTable()
```
    Check if this value is linked to a specific table. For values that are kept fully in memory, this method returns false.
    
    返回:
    
    true if it is
  - remove
```
public void remove()
```
    Remove the underlying resource, if any. For values that are kept fully in memory this method has no effect.
  - checkPrecision
```
public boolean checkPrecision(long precision)
```
    Check if the precision is smaller or equal than the given precision.
    
    参数:
    
    precision - the maximum precision
    
    返回:
    
    true if the precision of this value is smaller or equal to the given precision
  - getTraceSQL
```
public String getTraceSQL()
```
    Get a medium size SQL expression for debugging or tracing. If the precision is too large, only a subset of the value is returned.
    
    返回:
    
    the SQL expression
  - toString
```
public String toString()
```
    覆盖:
    
    toString 在类中 Object
  - throwUnsupportedExceptionForType
```
protected DbException throwUnsupportedExceptionForType(String op)
```
    Throw the exception that the feature is not support for the given data type.
    
    参数:
    
    op - the operation
    
    返回:
    
    never returns normally
    
    抛出:
    
    DbException - the exception
  - getTableId
```
public int getTableId()
```
    Get the table (only for LOB object).
    
    返回:
    
    the table id
  - getSmall
```
public byte[] getSmall()
```
    Get the byte array.
    
    返回:
    
    the byte array
  - copyToTemp
```
public Value copyToTemp()
```
    Copy this value to a temporary file if necessary.
    
    返回:
    
    the new value
  - copyToResult
```
public Value copyToResult()
```
    Create an independent copy of this value if needed, that will be bound to a result. If the original row is removed, this copy is still readable.
    
    返回:
    
    the value (this for small objects)
  - getResultSet
```
public ResultSet getResultSet()
```
  - getDataHandler
```
protected DataHandler getDataHandler()
```
    Return the data handler for the values that support it (actually only Java objects).
    
    返回:
    
    the data handler

类 Value

嵌套类概要

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

UNKNOWN

NULL

BOOLEAN

BYTE

SHORT

INT

LONG

DECIMAL

DOUBLE

FLOAT

TIME

DATE

TIMESTAMP

BYTES

STRING

STRING_IGNORECASE

BLOB

CLOB

ARRAY

RESULT_SET

JAVA_OBJECT

UUID

STRING_FIXED

GEOMETRY

TIMESTAMP_TZ

TYPE_COUNT

构造器详细资料

Value

方法详细资料

getSQL

getType

getPrecision

getDisplaySize

getMemory

getString

getObject

set

compareSecure

hashCode

equals

getHigherOrder

clearCache

getBoolean

getDate

getTime

getTimestamp

getBytes

getBytesNoCopy

getByte

getShort

getBigDecimal

getDouble

getFloat

getInt

getLong

getInputStream

getReader

add

getSignum

negate

subtract

divide

multiply

modulus

convertTo

compareTypeSafe

compareTo

getScale

convertScale

convertPrecision

copy

isLinkedToTable

remove