linux odbc 编程

#include <stdio.h>
#include <stdlib.h>
#include <sql.h>
#include <sqlext.h>

int main() {
    SQLHENV hEnv; // 环境句柄
    SQLHDBC hDbc; // 连接句柄
    SQLRETURN ret;

    // 分配环境句柄
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv);
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "Failed to allocate environment handle
");
        return EXIT_FAILURE;
    }

    // 设置ODBC版本
    ret = SQLSetEnvAttr(hEnv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "Failed to set ODBC version
");
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return EXIT_FAILURE;
    }

    // 分配连接句柄
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hEnv, &hDbc);
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "Failed to allocate connection handle
");
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return EXIT_FAILURE;
    }

    // 连接数据库（请根据实际情况修改DSN、用户名和密码）
    ret = SQLConnect(hDbc, (SQLCHAR*)"your_dsn", SQL_NTS, (SQLCHAR*)"your_username", SQL_NTS, (SQLCHAR*)"your_password", SQL_NTS);
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "Failed to connect to database
");
        SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return EXIT_FAILURE;
    }

    // 执行查询（请根据实际情况修改SQL语句）
    SQLHSTMT hStmt;
    ret = SQLAllocHandle(SQL_HANDLE_STMT, hDbc, &hStmt);
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "Failed to allocate statement handle
");
        SQLDisconnect(hDbc);
        SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return EXIT_FAILURE