tmudr::TypeInfo Class Reference

Data types in the UDR interface. More...

#include <sqludr.h>

Inherits tmudr::TMUDRSerializableObject.

Public Types
enum	SQLTypeCode { ,   SMALLINT, INT, LARGEINT, NUMERIC,   DECIMAL_LSE, SMALLINT_UNSIGNED, INT_UNSIGNED, NUMERIC_UNSIGNED,   DECIMAL_UNSIGNED, REAL, DOUBLE_PRECISION, CHAR,   VARCHAR, DATE, TIME, TIMESTAMP,   INTERVAL, BLOB, CLOB }
enum	SQLTypeClassCode {   CHARACTER_TYPE, NUMERIC_TYPE, DATETIME_TYPE, INTERVAL_TYPE,   LOB_TYPE, UNDEFINED_TYPE_CLASS }
enum	SQLTypeSubClassCode {   FIXED_CHAR_TYPE, VAR_CHAR_TYPE, EXACT_NUMERIC_TYPE, APPROXIMATE_NUMERIC_TYPE,   DATE_TYPE, TIME_TYPE, TIMESTAMP_TYPE, YEAR_MONTH_INTERVAL_TYPE,   DAY_SECOND_INTERVAL_TYPE, LOB_SUB_CLASS, UNDEFINED_TYPE_SUB_CLASS }
enum	SQLCharsetCode { , CHARSET_ISO88591, CHARSET_UTF8, CHARSET_UCS2 }
enum	SQLCollationCode { UNDEFINED_COLLATION, SYSTEM_COLLATION }
enum	SQLIntervalCode
Public Member Functions
	TypeInfo (const TypeInfo &type)
	TypeInfo (SQLTypeCode sqltype=UNDEFINED_SQL_TYPE, int length=0, bool nullable=false, int scale=0, SQLCharsetCode charset=CHARSET_UTF8, SQLIntervalCode intervalCode=UNDEFINED_INTERVAL_CODE, int precision=0, SQLCollationCode collation=SYSTEM_COLLATION)
SQLTypeCode	getSQLType () const
SQLTypeClassCode	getSQLTypeClass () const
SQLTypeSubClassCode	getSQLTypeSubClass () const
bool	getIsNullable () const
int	getScale () const
SQLCharsetCode	getCharset () const
SQLIntervalCode	getIntervalCode () const
int	getPrecision () const
SQLCollationCode	getCollation () const
int	getByteLength () const
int	getMaxCharLength () const
void	setNullable (bool nullable)

---

Detailed Description

Data types in the UDR interface.

Describes an SQL data type and the corresponding C/C++ type, used for scalar parameters, columns of input rows and columns of result rows.

---

Member Enumeration Documentation

enum tmudr::TypeInfo::SQLCharsetCode

Character sets

Enumerator:

CHARSET_ISO88591	ISO 8859-1, single byte western European characters.
CHARSET_UTF8	UTF-8, 1-4 byte Unicode encoding, length is in bytes.
CHARSET_UCS2	UCS-2, 16 bit Unicode encoding, tolerates UTF-16.

enum tmudr::TypeInfo::SQLCollationCode

Collations

Enumerator:

UNDEFINED_COLLATION	undefined value
SYSTEM_COLLATION	System collation, which is a binary collation, except that it ignores trailing blanks

enum tmudr::TypeInfo::SQLIntervalCode

Start and end fields of interval columns

enum tmudr::TypeInfo::SQLTypeClassCode

Classes of types defined in the SQL standard

Enumerator:

CHARACTER_TYPE	char and varchar types
NUMERIC_TYPE	exact and approximate numerics
DATETIME_TYPE	date/time/timestamp
INTERVAL_TYPE	day/month or hour/second intervals
LOB_TYPE	BLOBs and CLOBs.
UNDEFINED_TYPE_CLASS	undefined value

enum tmudr::TypeInfo::SQLTypeCode

SQL data types

Enumerator:

SMALLINT	16 bit integer
INT	32 bit integer
LARGEINT	64 bit integer
NUMERIC	Numeric with decimal precision.
DECIMAL_LSE	Decimal, leading sign embedded.
SMALLINT_UNSIGNED	unsigned 16 bit integer
INT_UNSIGNED	unsigned 32 bit integer
NUMERIC_UNSIGNED	unsigned numeric
DECIMAL_UNSIGNED	unsigned decimal
REAL	4 byte floating point number
DOUBLE_PRECISION	8 byte floating point number
CHAR	fixed length character types.
VARCHAR	varying length character types.
DATE	date
TIME	time
TIMESTAMP	timestamp
INTERVAL	interval
BLOB	Binary Large Object.
CLOB	Character Large Object.

enum tmudr::TypeInfo::SQLTypeSubClassCode

More detailed type information, but not as detailed as the actual type

Enumerator:

FIXED_CHAR_TYPE	CHAR types.
VAR_CHAR_TYPE	VARCHAR type.
EXACT_NUMERIC_TYPE	Exact numeric.
APPROXIMATE_NUMERIC_TYPE	Approximate numeric (floating point).
DATE_TYPE	Date.
TIME_TYPE	Time.
TIMESTAMP_TYPE	Timestamp (date + time + optional fractional seconds)
YEAR_MONTH_INTERVAL_TYPE	Intervals involving year and month.
DAY_SECOND_INTERVAL_TYPE	Intervals involving days/hours/minutes/seconds
LOB_SUB_CLASS	LOBs.
UNDEFINED_TYPE_SUB_CLASS	undefined value

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Constructor & Destructor Documentation

TypeInfo::TypeInfo

(

const TypeInfo &

type

)

Copy constructor

TypeInfo::TypeInfo	(	SQLTypeCode	sqlType = UNDEFINED_SQL_TYPE,
		int	length = 0,
		bool	nullable = false,
		int	scale = 0,
		SQLCharsetCode	charset = CHARSET_UTF8,
		SQLIntervalCode	intervalCode = UNDEFINED_INTERVAL_CODE,
		int	precision = 0,
		SQLCollationCode	collation = SYSTEM_COLLATION
	)

Default constructor, with optional arguments

Construct a TypeInfo object from an SQL type, with several optional arguments (including the SQL type). This is mostly used to create formal parameters or output columns in the compiler interface, if a more complex data type is required that is not covered by the TupleInfo::addXXXColumn() methods.

Parameters:

	sqlType	SQL type enum to construct the type from.
	length	Length of CHAR/VARCHAR types, not needed for other types. Note that the length for UTF-8 types is in bytes, not characters, so this is equivalent to [VAR]CHAR (length BYTES) CHARACTER SET UTF8
	nullable	Determines the NULL / NOT NULL attribute of the type Default: false (that means NOT NULL)
	scale	Scale for numeric type, fraction precision for fractional seconds, not needed for other types.
	charset	Character set enum for CHAR/VARCHAR types, not needed for other types.
	intervalCode	Interval code enum for intervals, not needed otherwise.
	precision	Precision for numeric types and leading precision for interval data types.
	collation	Collation enum for CHAR/VARCHAR types, not needed for other types. Note that only one type of collation is currently supported.

Exceptions:

UDRException

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Member Function Documentation

int TypeInfo::getByteLength

(

)

const

Get the length of a value of the type.

Getting the length is useful for CHAR/VARCHAR data types but probably not as useful for other types that may have an internal representation unknown to a UDR writer. This returns the length in bytes, not in characters.

See also:

getCharLength()

Returns:

Length in bytes.

TypeInfo::SQLCharsetCode TypeInfo::getCharset

(

)

const

Get the character set of the data type.

Returns:

Character set enum.

TypeInfo::SQLCollationCode TypeInfo::getCollation

(

)

const

Get the collation for char/varchar data types.

Note that, currently, only one collation is supported. This default collation is a binary collation, except that trailing blanks are ignored.

Returns:

Collation enum.

TypeInfo::SQLIntervalCode TypeInfo::getIntervalCode

(

)

const

Get the interval code for start/end fields.

Returns:

Interval code enum, indicating start and end fields of an interval type.

bool TypeInfo::getIsNullable

(

)

const

Get whether the type is nullable.

Returns:

True for nullable types, false for non-nullable types.

int TypeInfo::getMaxCharLength

(

)

const

Get the maximum number of characters that can be stored in this type.

This method should be used only for character types that have a fixed-width encoding. For variable-length encoding, like UTF-8, the method returns the highest possible number of characters (assuming single byte characters in the case of UTF-8). Right now, UTF-8 data types all have byte semantics, meaning there is no limit for the number of characters stored in a type, it is only limited by the number of bytes. The method returns 0 for numeric types. It returns the length of the string representation for types that are represented by a string, like datetime types.

See also:

getByteLength()

Returns:

Length in bytes.

Exceptions:

UDRException

int TypeInfo::getPrecision

(

)

const

Get the precision (max. number of significant digits).

The precision is the maximum number of digits before the decimal point a value can have. For interval types, this is the "leading precision". For example, an INTEGER value can range from -2,147,483,648 to 2,147,483,647. It's precision is 10, since the longest number has 10 digits. Note that not all 10 digit numbers can be represented in an integer. This is called binary precision. NUMERIC and DECIMAL types have decimal precision, meaning that a NUMERIC(10,0) type can represent values from -9,999,999,999 to +9,999,999,999.

Returns:

Precision of numeric types or interval types.

int TypeInfo::getScale

(

)

const

Get the scale of the data type.

For integer, largeint, etc. types the scale is 0, since these are integer data types. For NUMERIC and DECIMAL types, a scale can be specified. Timestamp and some interval data types have a "fraction precision" value, which is the number of digits allowed after the decimal point for seconds. This fraction precision is returned as the scale, since can be considered the scale of the seconds part. For other data types like CHAR, the scale value is meaningless.

Returns:

Scale (digits after the decimal point) for numeric types, fraction precision (digits of fractional seconds) for intervals.

TypeInfo::SQLTypeCode TypeInfo::getSQLType

(

)

const

Get the SQL type.

Returns:

SQL type enum.

TypeInfo::SQLTypeClassCode TypeInfo::getSQLTypeClass

(

)

const

Get the SQL type class.

Determine whether this is a numeric character, datetime or interval type.

Returns:

SQL type class enum.

TypeInfo::SQLTypeSubClassCode TypeInfo::getSQLTypeSubClass

(

)

const

Get the SQL type subclass.

This goes to one more level of detail beyond the type class, like exact/approximate numeric, char/varchar, etc.

Returns:

SQL type subclass enum.

void TypeInfo::setNullable

(

bool

nullable

)

Set the nullable attribute of a type

Use this method to set types created locally in the UDF to be nullable or not nullable.

Parameters:

nullable

true to set the type to nullable, false to give the type the NOT NULL attibute.

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The documentation for this class was generated from the following files:

• sqludr.h
• sqludr.cpp