Sybase 12.4.2 manual Data conversions in IQ, 205

		CHAPTER 5 Moving Data In and Out of Databases
	Adaptive Server IQ
Option	Datatypes	Action
ASCII	CHAR, VARCHAR	By default, Adaptive Server IQ assumes same column width
		between source and destination columns, which may cause it to
		read input file incorrectly. This option lets you specify a different
		width for the input column.
DATE	DATE	Converts ASCII date input of a fixed format to binary.
DATETIME	TIMESTAMP (or DATETIME)	Converts ASCII time or date/time input of a fixed format to
	or TIME	binary. The input specification is based on either a 12-hour or 24-
		hour clock.
TIME	TIME	Converts ASCII time input of a fixed format to binary.
NULL	all	Lets you specify which input data values to convert to NULL on
		insert.

Note When loading from a flat file, use binary data if you have a choice of using binary or character data. Using binary input can improve performance by eliminating conversion costs.

Data conversions in IQ

When you use the INSERT statement to insert data directly from a database rather than from a flat file, you cannot use the load conversion options. If the data requires explicit conversion, you must use one of the conversion functions, CAST or CONVERT, in the SELECT statement where you specify the data to be inserted. If the data is converted implicitly, Adaptive Server IQ handles the conversion automatically.

An implicit or explicit conversion is required whenever data types in a SELECT statement need to match, but do not. This occurs when you do an INSERT SELECT from one data type to another, but it also occurs whenever you compare or compute values for differing data types.

The following tables show:

•Which conversions Adaptive Server IQ does implicitly (I)

•Which conversions you must do explicitly (E)

•Which conversions are unsupported (U)

These conversions apply to data within an Adaptive Server IQ database, or coming from an Adaptive Server Anywhere database, or any other database connected as a Specialty Data Store.

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