Conversion and formatting with Informix GLS
The library provides functions that allow you to perform the conversion and formatting tasks on locale-specific data.
- Conversion
- Changes a string that contains locale-specific formats to the
internal representation of its value.
You usually perform conversion on a locale-specific string to prepare it for storage in a program variable or a database column.
- Formatting
- Changes the internal representation of a value to a locale-specific
string.
You usually perform formatting of a locale-specific string to prepare the internal representation of a value for display or printing to the end user.
The internal representation of a value is one that can be stored
directly in a database column. The following table lists the SQL data
types for the internal representations along with the ESQL/C and DataBlade®
API data
types that hold these internal representations.
| Type of data | SQL data type | ESQL/C data type | DataBlade API data type |
|---|---|---|---|
| Numeric | DECIMAL SMALLINT, INTEGER, INT8, FLOAT, SMALLFLOAT |
decimal (dec_t) | mi_decimal |
| Monetary | MONEY | decimal (dec_t) | mi_decimal |
| Date | DATE | date (long int) | mi_date |
| Date and time | DATETIME | datetime (dtime_t) | mi_datetime |
Numeric data types: Numeric data includes
integer, floating-point, and fixed-point numbers. The conversion
and formatting functions represent all these numeric data types with
the decimal (or mi_decimal) data type. To convert the decimal (or
mi_decimal) representation to an integer or floating-point value,
use a library function such as dectoint(), dectolong(),
or dectodbl(). For more information about these
decimal-conversion functions, see the
Informix® ESQL/C Programmer's Manual.
The following table lists the functions that the library
provides for the conversion and formatting of locale-specific data.
| Locale-specific data | Conversion | Formatting |
|---|---|---|
| Numeric | ifx_gl_convert_number() | ifx_gl_format_number() |
| Monetary | ifx_gl_convert_money() | ifx_gl_format_money() |
| Date | ifx_gl_convert_date() | ifx_gl_format_date() |
| Date/time | ifx_gl_convert_datetime() | ifx_gl_format_datetime() |
The conversion and formatting functions in the preceding table
accept a format string to indicate how to handle a locale-specific
string. A format string is composed of white spaces, ordinary characters,
and one or more formatting directives. A formatting directive
consists of the following characters:
- A percent symbol (%)
- Optional format modifiers
- A type-specifier character, which determines the type of conversion
For example, the ifx_gl_convert_number() function
supports the following formatting directive: %0x
In the preceding formatting directive, 0 is a format modifier that indicates padding, and x is a type specifier that indicates the hexadecimal format of a number.