更新日期:2024年09月11日
rtypname() 函数返回包含指定的 SQL 数据类型的名称的以空终止的字符串。
语法
char *rtypname(sqltype)
mint sqltype;
sqltype
SQL 数据类型之一的整数代码。
rtypname() 函数将
(sqltypes.h 定义的)
GBase 8s SQL 数据类型的常量转换为字符串。
返回代码
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 918 -
rtypname() 函数返回指向包含 sqltype 指定的数据类型的名称的字符串的指针。如果
sqltype 是无效的值,则 rtypname() 返回空字符串(" ")。
示例
此样例程序在 demo 目录中的 rtypname.ec 文件中。
/*
* rtypname.ec *
This program displays the name and the data type of each column in the 'orders' table.
*/
#include
EXEC SQL include sqltypes;
#define WARNNOTIFY 1
#define NOWARNNOTIFY 0
main(argc, argv)
int argc;
char *argv[];
{
mint i;
int4 err_chk();
char db_stmnt[50];
char *rtypname();
struct sqlda *sql_desc;
struct sqlvar_struct *col;
EXEC SQL BEGIN DECLARE SECTION;
char db_name[20];
EXEC SQL END DECLARE SECTION;
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 919 -
printf("RTYPNAME Sample ESQL Program running.\n\n");
if (argc > 2) /* correct no. of args? */
{
printf("\nUsage: %s [database]\nIncorrect no. of argument(s)\n",
argv[0]);
exit(1);
}
strcpy(db_name, "stores7");
if (argc == 2)
strcpy(db_name, argv[1]);
EXEC SQL connect to :db_name;
sprintf(db_stmnt, "CONNECT TO %s", argv[1]);
exp_chk(db_stmnt, NOWARNNOTIFY);
printf("Connected to '%s' database.", db_name);
EXEC SQL prepare query_1 from 'select * from orders';
/* prepare select */
if(exp_chk("Prepare", WARNNOTIFY) == 1)
exit(1);
/* initialize sqlda */
EXEC SQL describe query_1 into sql_desc;
if(exp_chk("Describe", WARNNOTIFY) == 1)
exit(1);
printf("\n\tColumn Name \t\tSQL type\n\n");
/*
* For each column in the orders table display the column name and the name
of the SQL data type
*/
for (i = 0, col = sql_desc->sqlvar; i < sql_desc->sqld; i++, col++)
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 920 -
printf("\t%-15s\t\t%s\n",col->sqlname, rtypname(col->sqltype));
printf("\nRTYPNAME Sample Program over.\n\n");
}
/*
* The exp_chk() file contains the exception handling functions to check the
SQLSTATE status variable to see if an error has occurred following an SQL statement. If a
warning or an error has occurred, exp_chk() executes the GET DIAGNOSTICS statement and
prints the detail for each exception that is returned.
*/
EXEC SQL include exp_chk.ec
输出
RTYPNAME Sample ESQL Program running.
Connected to stores7 database
Column Name SQL type
order_num serial
order_date date
customer_num integer
ship_instruct char
backlog char
po_num char
ship_date date
ship_weight decimal
ship_charge money
paid_date date
RTYPNAME Sample Program over.
GBase 8s ESQL/C 编程指南
南大通用数据技术股份有限公司
- 921 -