假定用于分析的数据包含属性age。数据元组中age的值如下（按递增序）：13, 15, 16, 16, 19, 20, 20, 21, 22, 22, 25, 25, 25, 25, 30, 33, 33, 35, 35, 35, 35, 36, 40, 45, 46, 52, 70。使用c语言实现,使用ODBC连接数据库。实现如下功能（要求程序具有通用性）： (a) 使用按箱平均值平滑法对以上数据进行平滑，箱的深度为3。 (b) 使用按箱中值平滑法对以上数据进行平滑，箱的深度为3。 (c) 使用按箱边界值平滑法对以上数据进行平滑，箱的深度为3。

由于题目要求使用ODBC连接数据库，需要先建立连接并获取数据，以下是一个简单的连接数据库并获取数据的示例代码：

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

int main() {
    SQLHENV env;
    SQLHDBC dbc;
    SQLHSTMT stmt;
    SQLRETURN ret;

    // Allocate environment handle
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error allocating environment handle\n");
        return 1;
    }

    // Set the ODBC version environment attribute
    ret = SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error setting environment attribute\n");
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // Allocate connection handle
    ret = SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error allocating connection handle\n");
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // Connect to the database
    ret = SQLDriverConnect(dbc, NULL, "DSN=yourdsn;UID=youruid;PWD=yourpwd", SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error connecting to database\n");
        SQLFreeHandle(SQL_HANDLE_DBC, dbc);
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // Allocate statement handle
    ret = SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error allocating statement handle\n");
        SQLDisconnect(dbc);
        SQLFreeHandle(SQL_HANDLE_DBC, dbc);
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // Execute SQL statement to retrieve data
    ret = SQLExecDirect(stmt, "SELECT age FROM mytable", SQL_NTS);
    if (!SQL_SUCCEEDED(ret)) {
        printf("Error executing SQL statement\n");
        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
        SQLDisconnect(dbc);
        SQLFreeHandle(SQL_HANDLE_DBC, dbc);
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // Fetch the data
    SQLINTEGER age;
    while (SQLFetch(stmt) == SQL_SUCCESS) {
        SQLGetData(stmt, 1, SQL_C_LONG, &age, sizeof(age), NULL);
        // Process the retrieved data here
    }

    // Free resources
    SQLFreeHandle(SQL_HANDLE_STMT, stmt);
    SQLDisconnect(dbc);
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);
    SQLFreeHandle(SQL_HANDLE_ENV, env);

    return 0;
}

对于数据平滑的部分，以下是使用C语言实现的按箱平均值、按箱中值和按箱边界值三种平滑方法的代码示例：

#include <stdio.h>

// 按箱平均值平滑
void boxcar_smooth_mean(int data[], int n, int depth, int output[]) {
    int i, j, sum;
    for (i = 0; i < n; i++) {
        sum = 0;
        for (j = i - depth; j <= i + depth; j++) {
            if (j >= 0 && j < n) {
                sum += data[j];
            }
        }
        output[i] = sum / (2 * depth + 1);
    }
}

// 按箱中值平滑
void boxcar_smooth_median(int data[], int n, int depth, int output[]) {
    int i, j, k, temp;
    for (i = 0; i < n; i++) {
        int window[2 * depth + 1];
        for (j = i - depth, k = 0; j <= i + depth; j++, k++) {
            if (j >= 0 && j < n) {
                window[k] = data[j];
            }
        }
        for (j = 0; j < 2 * depth; j++) {
            for (k = j + 1; k < 2 * depth + 1; k++) {
                if (window[j] > window[k]) {
                    temp = window[j];
                    window[j] = window[k];
                    window[k] = temp;
                }
            }
        }
        output[i] = window[depth];
    }
}

// 按箱边界值平滑
void boxcar_smooth_boundary(int data[], int n, int depth, int output[]) {
    int i, j;
    for (i = 0; i < n; i++) {
        int window[2 * depth + 1];
        for (j = i - depth; j <= i + depth; j++) {
            if (j >= 0 && j < n) {
                window[j - (i - depth)] = data[j];
            } else {
                window[j - (i - depth)] = data[i];
            }
        }
        int min = window[0], max = window[0], k;
        for (k = 1; k < 2 * depth + 1; k++) {
            if (window[k] < min) {
                min = window[k];
            }
            if (window[k] > max) {
                max = window[k];
            }
        }
        if (data[i] < min) {
            output[i] = min;
        } else if (data[i] > max) {
            output[i] = max;
        } else {
            output[i] = data[i];
        }
    }
}

int main() {
    // 假设原始数据存储在数组data中
    int data[] = {13, 15, 16, 16, 19, 20, 20, 21, 22, 22, 25, 25, 25, 25, 30, 33, 33, 35, 35, 35, 35, 36, 40, 45, 46, 52, 70};
    int n = sizeof(data) / sizeof(int);

    // 使用按箱平均值平滑法对数据进行平滑
    int smoothed_mean[n];
    boxcar_smooth_mean(data, n, 1, smoothed_mean);

    // 使用按箱中值平滑法对数据进行平滑
    int smoothed_median[n];
    boxcar_smooth_median(data, n, 1, smoothed_median);

    // 使用按箱边界值平滑法对数据进行平滑
    int smoothed_boundary[n];
    boxcar_smooth_boundary(data, n, 1, smoothed_boundary);

    // 输出平滑后的数据
    int i;
    printf("Using boxcar mean smoothing:\n");
    for (i = 0; i < n; i++) {
        printf("%d ", smoothed_mean[i]);
    }
    printf("\n");

    printf("Using boxcar median smoothing:\n");
    for (i = 0; i < n; i++) {
        printf("%d ", smoothed_median[i]);
    }
    printf("\n");

    printf("Using boxcar boundary smoothing:\n");
    for (i = 0; i < n; i++) {
        printf("%d ", smoothed_boundary[i]);
    }
    printf("\n");

    return 0;
}

以上代码仅作为示例，实际使用时可能需要根据具体情况进行修改和优化。