Difference between revisions of "EXPRESSION()"
From Recital Documentation Wiki
Yvonnemilne (Talk | contribs) |
Yvonnemilne (Talk | contribs) |
||
| Line 28: | Line 28: | ||
<code lang="c"> | <code lang="c"> | ||
struct API_EXPRESSION{ | struct API_EXPRESSION{ | ||
| − | int errno; /* RECITAL error() number */ | + | int errno; /* RECITAL error() number */ |
| − | char type; | + | char type; /* data type of result */ |
| − | int width; /* width of result | + | int width; /* width of result */ |
int decimal; /* decimal places */ | int decimal; /* decimal places */ | ||
| − | char *character; /* CHARACTER result | + | char *character; /* CHARACTER result */ |
| − | double number; /* NUMERIC result | + | double number; /* NUMERIC result */ |
| − | char logical; /* LOGICAL result | + | char logical; /* LOGICAL result */ |
| − | unsigned long date; | + | unsigned long date; /* Recital DATE result */ |
| − | DATETIME datetime; /* Recital DATETIME result */ | + | DATETIME datetime; /* Recital DATETIME result */ |
| − | CURRENCY currency; /* Recital CURRENCY result */ | + | CURRENCY currency; /* Recital CURRENCY result */ |
}; | }; | ||
</code> | </code> | ||
Latest revision as of 12:07, 30 March 2009
PURPOSE
Evaluate a Recital expression
SYNONYM
api_expression()
SYNOPSIS
#include "dbapi.h" int EXPRESSION(result, exp) <input parameters> char *exp; /* Address of a buffer containing a valid Recital command */ <output parameters> API_EXPRESSION result; /* Expression result */
DESCRIPTION
The FUNCTION() function evaluates the specified Recital expression and returns the result. This function returns 0 if successful, otherwise a Recital error number.
The API Expression result structure is defined as follows:
struct API_EXPRESSION{ int errno; /* RECITAL error() number */ char type; /* data type of result */ int width; /* width of result */ int decimal; /* decimal places */ char *character; /* CHARACTER result */ double number; /* NUMERIC result */ char logical; /* LOGICAL result */ unsigned long date; /* Recital DATE result */ DATETIME datetime; /* Recital DATETIME result */ CURRENCY currency; /* Recital CURRENCY result */ };
The data type result will be any one of the following:
| RETURN VALUE | DESCRIPTION |
|---|---|
| C | character or memo data type |
| N | numeric data type |
| D | date data type |
| L | logical data type |
| T | datetime data type |
| Y | currency data type |
EXAMPLE
The following example evaluates the specified expression and returns the result.
Example Recital program:
use accounts m_result=evaluate("ord_value - paid_value") return
Example 'C' function:
#include "dbapi.h" dbapi_evaluate() { struct API_EXPRESSION result; if (_parinfo(1) == API_CTYPE) { EXPRESSION(&result, _parc(1)); if (result.errno != 0) { _retni(-1); } else { _retnd(result.number); } } else { _retni(-1); } }
