org.h2.value

Class DataType

java.lang.Object

org.h2.value.DataType

public class DataType
extends java.lang.Object

This class contains meta data information about data types, and can convert between Java objects and Values.

Field Summary

Fields

Modifier and Type	Field and Description
boolean	caseSensitive If this data type is case sensitive.
long	defaultPrecision The default precision.
int	defaultScale The default scale.
long	maxPrecision The maximum supported precision.
int	maxScale The highest possible scale.
long	minPrecision The minimum supported precision.
int	minScale The lowest possible scale.
java.lang.String	params The list of parameters used in the column definition.
java.lang.String	prefix The prefix required for the SQL literal representation.
boolean	specialPrecisionScale If precision and scale have non-standard default values.
int	sqlType The SQL type.
java.lang.String	suffix The suffix required for the SQL literal representation.
boolean	supportsPrecision If the precision parameter is supported.
boolean	supportsScale If the scale parameter is supported.
int	type The value type of this data type.

Constructor Summary

Constructors

Constructor and Description
DataType()

Method Summary

Modifier and Type	Method and Description
static long	addPrecision(long p1, long p2) Performs saturated addition of precision values.
static boolean	areStableComparable(TypeInfo type1, TypeInfo type2) Returns whether values of the specified data types have session-independent compare results.
static int	convertSQLTypeToValueType(int sqlType) Convert a SQL type to a value type.
static int	convertSQLTypeToValueType(int sqlType, java.lang.String sqlTypeName) Convert a SQL type to a value type using SQL type name, in order to manage SQL type extension mechanism.
static int	convertSQLTypeToValueType(java.sql.SQLType sqlType) Convert a SQL type to a value type.
static int	convertTypeToSQLType(TypeInfo type) Convert a value type to a SQL type.
static DataType	createDate(int maxPrecision, int precision, java.lang.String prefix, boolean supportsScale, int scale, int maxScale) Create a date-time data type.
static DataType	createNumeric(int precision, int scale) Create a numeric data type without parameters.
static DataType	getDataType(int type) Get the data type object for the given value type.
static java.lang.Object	getDefaultForPrimitiveType(java.lang.Class<?> clazz) Get the default value in the form of a Java object for the given Java class.
static DataType	getTypeByName(java.lang.String s, Mode mode) Get a data type object from a type name.
static int	getValueTypeFromResultSet(java.sql.ResultSetMetaData meta, int columnIndex) Get the SQL type from the result set meta data for the given column.
static boolean	hasTotalOrdering(int type) Check if the given type has total ordering.
static boolean	isBinaryColumn(java.sql.ResultSetMetaData meta, int column) Check whether the specified column needs the binary representation.
static boolean	isBinaryStringOrSpecialBinaryType(int type) Check if the given value type is a binary string type or a compatible special data type such as Java object, UUID, geometry object, or JSON.
static boolean	isBinaryStringType(int type) Check if the given value type is a binary string type.
static boolean	isCharacterStringType(int type) Check if the given value type is a character string type.
static boolean	isDateTimeType(int type) Check if the given value type is a date-time type (TIME, DATE, TIMESTAMP, TIMESTAMP_TZ).
static boolean	isIndexable(TypeInfo type) Returns whether columns with the specified data type may have an index.
static boolean	isIntervalType(int type) Check if the given value type is an interval type.
static boolean	isLargeObject(int type) Check if the given value type is a large object (BLOB or CLOB).
static boolean	isNumericType(int type) Check if the given value type is a numeric type.
static boolean	isStringType(int type) Check if the given value type is a String (VARCHAR,...).
static boolean	isYearMonthIntervalType(int type) Check if the given value type is a year-month interval type.
static java.lang.String	sqlTypeToString(java.sql.SQLType sqlType) Convert a SQL type to a debug string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

type

public int type

The value type of this data type.

sqlType

public int sqlType

The SQL type.

minPrecision

public long minPrecision

The minimum supported precision.

maxPrecision

public long maxPrecision

The maximum supported precision.

minScale

public int minScale

The lowest possible scale.

maxScale

public int maxScale

The highest possible scale.

prefix

public java.lang.String prefix

The prefix required for the SQL literal representation.

suffix

public java.lang.String suffix

The suffix required for the SQL literal representation.

params

public java.lang.String params

The list of parameters used in the column definition.

caseSensitive

public boolean caseSensitive

If this data type is case sensitive.

supportsPrecision

public boolean supportsPrecision

If the precision parameter is supported.

supportsScale

public boolean supportsScale

If the scale parameter is supported.

defaultPrecision

public long defaultPrecision

The default precision.

defaultScale

public int defaultScale

The default scale.

specialPrecisionScale

public boolean specialPrecisionScale

If precision and scale have non-standard default values.

Constructor Detail

DataType

public DataType()

Method Detail

createNumeric

public static DataType createNumeric(int precision,
                                     int scale)

Create a numeric data type without parameters.

Parameters:

precision - precision

scale - scale

Returns:

data type

createDate

public static DataType createDate(int maxPrecision,
                                  int precision,
                                  java.lang.String prefix,
                                  boolean supportsScale,
                                  int scale,
                                  int maxScale)

Create a date-time data type.

Parameters:

maxPrecision - maximum supported precision

precision - default precision

prefix - the prefix for SQL literal representation

supportsScale - whether the scale parameter is supported

scale - default scale

maxScale - highest possible scale

Returns:

data type

getDataType

public static DataType getDataType(int type)

Get the data type object for the given value type.

Parameters:

type - the value type

Returns:

the data type object

convertTypeToSQLType

public static int convertTypeToSQLType(TypeInfo type)

Convert a value type to a SQL type.

Parameters:

type - the type

Returns:

the SQL type

convertSQLTypeToValueType

public static int convertSQLTypeToValueType(int sqlType,
                                            java.lang.String sqlTypeName)

Convert a SQL type to a value type using SQL type name, in order to manage SQL type extension mechanism.

Parameters:

sqlType - the SQL type

sqlTypeName - the SQL type name

Returns:

the value type

getValueTypeFromResultSet

public static int getValueTypeFromResultSet(java.sql.ResultSetMetaData meta,
                                            int columnIndex)
                                     throws java.sql.SQLException

Get the SQL type from the result set meta data for the given column. This method uses the SQL type and type name.

Parameters:

meta - the meta data

columnIndex - the column index (1, 2,...)

Returns:

the value type

Throws:

java.sql.SQLException - on failure

isBinaryColumn

public static boolean isBinaryColumn(java.sql.ResultSetMetaData meta,
                                     int column)
                              throws java.sql.SQLException

Check whether the specified column needs the binary representation.

Parameters:

meta - metadata

column - column index

Returns:

true if column needs the binary representation, false otherwise

Throws:

java.sql.SQLException - on SQL exception

convertSQLTypeToValueType

public static int convertSQLTypeToValueType(java.sql.SQLType sqlType)

Convert a SQL type to a value type.

Parameters:

sqlType - the SQL type

Returns:

the value type

convertSQLTypeToValueType

public static int convertSQLTypeToValueType(int sqlType)

Convert a SQL type to a value type.

Parameters:

sqlType - the SQL type

Returns:

the value type

sqlTypeToString

public static java.lang.String sqlTypeToString(java.sql.SQLType sqlType)

Convert a SQL type to a debug string.

Parameters:

sqlType - the SQL type

Returns:

the textual representation

getTypeByName

public static DataType getTypeByName(java.lang.String s,
                                     Mode mode)

Get a data type object from a type name.

Parameters:

s - the type name

mode - database mode

Returns:

the data type object

isIndexable

public static boolean isIndexable(TypeInfo type)

Returns whether columns with the specified data type may have an index.

Parameters:

type - the data type

Returns:

whether an index is allowed

areStableComparable

public static boolean areStableComparable(TypeInfo type1,
                                          TypeInfo type2)

Returns whether values of the specified data types have session-independent compare results.

Parameters:

type1 - the first data type

type2 - the second data type

Returns:

are values have session-independent compare results

isDateTimeType

public static boolean isDateTimeType(int type)

Check if the given value type is a date-time type (TIME, DATE, TIMESTAMP, TIMESTAMP_TZ).

Parameters:

type - the value type

Returns:

true if the value type is a date-time type

isIntervalType

public static boolean isIntervalType(int type)

Check if the given value type is an interval type.

Parameters:

type - the value type

Returns:

true if the value type is an interval type

isYearMonthIntervalType

public static boolean isYearMonthIntervalType(int type)

Check if the given value type is a year-month interval type.

Parameters:

type - the value type

Returns:

true if the value type is a year-month interval type

isLargeObject

public static boolean isLargeObject(int type)

Check if the given value type is a large object (BLOB or CLOB).

Parameters:

type - the value type

Returns:

true if the value type is a lob type

isNumericType

public static boolean isNumericType(int type)

Check if the given value type is a numeric type.

Parameters:

type - the value type

Returns:

true if the value type is a numeric type

isBinaryStringType

public static boolean isBinaryStringType(int type)

Check if the given value type is a binary string type.

Parameters:

type - the value type

Returns:

true if the value type is a binary string type

isCharacterStringType

public static boolean isCharacterStringType(int type)

Check if the given value type is a character string type.

Parameters:

type - the value type

Returns:

true if the value type is a character string type

isStringType

public static boolean isStringType(int type)

Check if the given value type is a String (VARCHAR,...).

Parameters:

type - the value type

Returns:

true if the value type is a String type

isBinaryStringOrSpecialBinaryType

public static boolean isBinaryStringOrSpecialBinaryType(int type)

Check if the given value type is a binary string type or a compatible special data type such as Java object, UUID, geometry object, or JSON.

Parameters:

type - the value type

Returns:

true if the value type is a binary string type or a compatible special data type

hasTotalOrdering

public static boolean hasTotalOrdering(int type)

Check if the given type has total ordering.

Parameters:

type - the value type

Returns:

true if the value type has total ordering

addPrecision

public static long addPrecision(long p1,
                                long p2)

Performs saturated addition of precision values.

Parameters:

p1 - the first summand

p2 - the second summand

Returns:

the sum of summands, or Long.MAX_VALUE if either argument is negative or sum is out of range

getDefaultForPrimitiveType

public static java.lang.Object getDefaultForPrimitiveType(java.lang.Class<?> clazz)

Get the default value in the form of a Java object for the given Java class.

Parameters:

clazz - the Java class

Returns:

the default object