ODBC基本调用流程请参考官方文档基本 ODBC 应用程序 - ODBC API Reference | Microsoft Docs (opens new window)。

ODBC官方Demo见C/C++ ODBC 应用程序访问 SQL 数据库 - ODBC Driver for SQL Server | Microsoft Docs (opens new window)。

YashanDB ODBC驱动示例

本示例以visual studio作为工具进行编译和运行：

1. 创建一个新项目：

   

2. 创建OdbcExample.c文件：

   

3. 编写用户程序代码，如下：（YashanDB_Default_DSN为安装说明中已配置的ODBC数据源名称）

   #include <windows.h>
   
   #include <sql.h>
   #include <sqlext.h>
   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>
   #include <assert.h>
   
   void HandleDiagnosticRecord(SQLHANDLE hHandle, SQLSMALLINT hType, RETCODE RetCode)
   {
       SQLSMALLINT iRec = 0;
       SQLINTEGER  iError;
       CHAR        wszMessage[1000];
       CHAR        wszState[SQL_SQLSTATE_SIZE + 1];
   
       if (RetCode == SQL_INVALID_HANDLE) {
           printf("Invalid handle!\n");
           return;
       }
   
       while (SQLGetDiagRec(hType, hHandle, ++iRec, wszState, &iError, wszMessage,
           (SQLSMALLINT)(sizeof(wszMessage) / sizeof(CHAR)), (SQLSMALLINT*)NULL) == SQL_SUCCESS) {
           // Hide data truncated..
           if (strcmp(wszState, "01004")) {
               printf("[%5.5s] %s (%d)\n", wszState, wszMessage, iError);
           }
       }
   }
   
   #define ODBC_TEST_CALL(yocFunc)                                             \
       do {                                                                    \
           SQLRETURN r = yocFunc;                                              \
           if (r == SQL_ERROR || r == SQL_NO_DATA_FOUND) {                     \
               HandleDiagnosticRecord(gTestHandles.hStmt, SQL_HANDLE_STMT, r); \
               return r;                                                       \
           }                                                                   \
       } while (0)
   
   #define CI_DATA_SOURCE "YashanDB_Default_DSN"
   
   typedef struct {
       SQLHENV  hEnv;
       SQLHDBC  hDbc;
       SQLHSTMT hStmt;
   } SQLHandles;
   
   SQLHandles gTestHandles;
   
   int main(int argc, char** argv)
   {
       if (SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &gTestHandles.hEnv) != SQL_SUCCESS) {
           printf("Unable to allocate an environment handle\n");
           return SQL_ERROR;
       }
   
       SQLSetEnvAttr(gTestHandles.hEnv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0);
   
       if (SQLAllocHandle(SQL_HANDLE_DBC, gTestHandles.hEnv, &gTestHandles.hDbc) != SQL_SUCCESS) {
           printf("Unable to allocate an connection handle\n");
           return SQL_ERROR;
       }
   
       if (SQLConnect(gTestHandles.hDbc, CI_DATA_SOURCE, SQL_NTS, NULL, SQL_NTS, NULL, SQL_NTS) != SQL_SUCCESS) {
           printf("Unable to connect\n");
           return SQL_ERROR;
       }
   
       //或者可以使用有图形化界面的SQLDriverConnect代替SQLConnect连接
       // SQLCHAR driverConnStr[100] = "DSN=";
       // strcat(driverConnStr, CI_DATA_SOURCE);
       // strcat(driverConnStr, ";");
   
       // if (SQLDriverConnect(gTestHandles.hDbc, NULL, driverConnStr, SQL_NTS, NULL, 0, NULL, SQL_DRIVER_PROMPT) !=
       //     SQL_SUCCESS) {
       //     printf("Unable to Dirver connect\n");
       //     return SQL_ERROR;
       // }
   
       if (SQLAllocHandle(SQL_HANDLE_STMT, gTestHandles.hDbc, &gTestHandles.hStmt) != SQL_SUCCESS) {
           printf("Unable to allocate an connection handle\n");
           return SQL_ERROR;
       }
   
       // 简单的绑定入参和取数据
       // 以产品信息表product为例，遵循以下示例将获得product_no等于11001的product_name
       ODBC_TEST_CALL(SQLPrepare(gTestHandles.hStmt, "select product_name from product where product_no = ?", SQL_NTS));
       SQLINTEGER productNo = 11001;
       SQLLEN     indicator = sizeof(SQLINTEGER);
       ODBC_TEST_CALL(SQLBindParameter(gTestHandles.hStmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 0, 0, &productNo,
           indicator, &indicator));
       ODBC_TEST_CALL(SQLExecute(gTestHandles.hStmt));
       SQLCHAR productName[100];
       ODBC_TEST_CALL(SQLBindCol(gTestHandles.hStmt, 1, SQL_C_CHAR, &productName, 100, NULL));
       ODBC_TEST_CALL(SQLFetch(gTestHandles.hStmt));
       ODBC_TEST_CALL(SQLCloseCursor(gTestHandles.hStmt));  //此步骤为必须步骤，否则之后调用其他函数会返回SQL_ERROR
       printf("product_no %d's product_name is \"%s\"\n", productNo, productName);
   
       // 释放资源
       if (SQLFreeHandle(SQL_HANDLE_STMT, gTestHandles.hStmt) != SQL_SUCCESS) {
           printf("Unable to free stmt\n");
           return SQL_ERROR;
       }
   
       if (SQLDisconnect(gTestHandles.hDbc) != SQL_SUCCESS) {
           printf("Unable to disconnect\n");
           return SQL_ERROR;
       }
   
       if (SQLFreeHandle(SQL_HANDLE_DBC, gTestHandles.hDbc) != SQL_SUCCESS) {
           printf("Unable to free conn\n");
           return SQL_ERROR;
       }
   
       if (SQLFreeHandle(SQL_HANDLE_ENV, gTestHandles.hEnv) != SQL_SUCCESS) {
           printf("Unable to free env\n");
           return SQL_ERROR;
       }
   
       return SQL_SUCCESS;
   }
   

4. 生成解决方案。（请注意visual studio的解决方案配置中平台须为x64，调试属性中的字符集须为使用多字节字符集）

5. 执行解决方案，输出如下：