ifx_int8sub() 函数将两个 int8 类型值相减。
语法
mint ifx_int8sub(n1, n2, difference)
ifx_int8_t *n1;
ifx_int8_t *n2;
ifx_int8_t *difference;
n1
指向包含第一个运算对象的 int8 结构的指针。
n2
指向包含第二个运算对象的 int8 结构的指针。
difference
指向包含 n1 与 n2 的差(n1 - n2)的 int8 结构的指针。
用法
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 744 -
difference 可与 n1 或 n2 相同。
返回代码
0
减法成功。
-1284
减法导致溢出或下溢。
示例
demo 目录中的文件 int8sub.ec 包含下列样例程序。
/*
*int8sub.ec *
The following program obtains the difference of two INT8 type values.
*/
#include
EXEC SQL include "int8.h";
char string1[] = "6";
char string2[] = "9,223,372,036,854,775";
char string3[] = "999,999,999,999,999.5";
char result[41];
main()
{
mint x;
ifx_int8_t num1, num2, num3, sum;
printf("IFX_INT8SUB Sample ESQL Program running.\n\n");
if (x = ifx_int8cvasc(string1, strlen(string1), &num1))
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 745 -
{
printf("Error %d in converting string1 to INT8\n", x);
exit(1);
}
if (x = ifx_int8cvasc(string2, strlen(string2), &num2))
{
printf("Error %d in converting string2 to INT8\n", x);
exit(1);
}
/* subtract num2 from num1 */
if (x = ifx_int8sub(&num1, &num2, ∑))
{
printf("Error %d in subtracting INT8s\n", x);
exit(1);
}
if (x = ifx_int8soasc(∑, result, sizeof(result)))
{
printf("Error %d in converting INT8 result to string\n", x);
exit(1);
}
result[40] = '\0';
printf("\t%s - %s = %s\n", string1, string2, result);
/* display result */
if (x = ifx_int8cvasc(string3, strlen(string3), &num3))
{
printf("Error %d in converting string3 to INT8\n", x);
exit(1);
}
/* notice that digits right of the decimal are truncated. */
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 746 -
if (x = ifx_int8sub(&num2, &num3, ∑))
{
printf("Error %d in subtracting INT8s\n", x);
exit (1);
}
if (x = ifx_int8soasc(∑, result, sizeof(result)))
{
printf("Error %d in converting INT8 result to string\n", x);
exit(1);
}
result[40] = '\0';
printf("\t%s - %s = %s\n", string2, string3, result);
/* display result */
printf("\nIFX_INT8SUB Sample Program over.\n\n");
exit(0);
}
输出
IFX_INT8SUB Sample ESQL Program running.
6 - 9,223,372,036,854,775 = -9223372036854769
9,223,372,036,854,775 - 999,999,999,999,999.5
= 8223372036854776
IFX_INT8SUB Sample Program over.