测试总结

对于mud数据库的开发单个字段的查询返回单个数据，多个字段应拼接成mapping。 数据的插入和更新组成接口，将mapping解析成语句即可。 数据库使用可以保持长连接，如想使用多数据库在不同代码平台上开发，可以在master主控程序上封装自己的配置文件。当配置文件改动时，使用的数据库一同改动。

使用数据库的好处

当多个数据库串联起来时，有些数据和功能就不用使用lpc去处理了，因为本质上玩家的属性只是数据，做好数据在不同平台的传输和处理，就能在其他代码平台上开发更强大的功能

#include <mysql.h>
#include <ansi.h>

private mixed myDb, line;
mixed obtain_message(int i);
private mixed implode_sql_value(mixed *sqlArray,string del);

//当精灵启动时，创建数据库长连接
void create()
{
    seteuid(getuid());
    // set("channel_id", "数据库精灵");
    myDb = db_connect(DB_HOST, DB_NAME, DB_USER, __USE_MYSQL__);
}

//数据库执行sql语句。
mixed exec_sentence(string sentence)
{
    line = db_exec(myDb, sentence);
    return line;
}

//字段值的连接
mixed implode_sql_value(mixed *sqlArray,string del)
{
    string resultMsg = "";
    foreach (mixed value in sqlArray)
    {
        switch (typeof(value))
        {
        case "int":
        case "float":
            resultMsg += value + del;
            break;
        default:
            resultMsg += "'" + value + "'" + del;
            break;
        }
    }
    return resultMsg[0.. < sizeof(del) + 1];
}

//支持单查询，多查询,约束查询
mixed query_data(string id, string tableName, mixed queryBody, int all, mapping where)
{
    string sqlSentence;
    int type = 0;
    if (!all)
    {
        if (arrayp(queryBody))
        {
            sqlSentence = sprintf("select %s from %s where id='%s';", implode(queryBody, ","), tableName, id);
        }
        else if (stringp(queryBody))
        {   
            if (queryBody != "*")
            type = 1;
            sqlSentence = sprintf("select %s from %s where id='%s';", queryBody, tableName, id);
        }
    }
    else
    {
        string *constraint = keys(where);

        foreach (string key in constraint)
        {
            key += sprintf("='%s'",where[key]);
        }

        if (arrayp(queryBody))
        {
            sqlSentence = sprintf("select %s from %s where id='%s',;", implode(queryBody, ","), tableName, id, implode(constraint, ","));
        }
        else if (stringp(queryBody))
        {
            if (queryBody != "*")
            type = 1;
            sqlSentence = sprintf("select %s from %s where id='%s',;", queryBody, tableName, id, implode(constraint, ","));
        }
    }

    exec_sentence(sqlSentence);
    return obtain_message(type);
}

//插入数据
mixed insert_data(string tableName,mapping data)
{
    string sqlSentence;
    mixed *constraint = values(data);
    mixed valued;

    valued = implode_sql_value(constraint,",");

    sqlSentence = sprintf("insert into %s (%s) values (%s);",tableName,implode(keys(data),","),valued);
    return exec_sentence(sqlSentence);
}

//更新数据
mixed update_data(string id,string tableName,mapping data)
{
    string sqlSentence;
    mixed *constraint = keys(data),*valued = ({});

    foreach (string key in constraint)
    {
        valued += ({ key + "='" + data[key] + "'" });
    }

    sqlSentence = sprintf("update %s set %s where id='%s';",tableName,implode(valued,","),id);
    return exec_sentence(sqlSentence);
}

//关闭数据库连接
mixed close()
{
    return db_close(myDb);
}

//重新连接数据库
mixed connect()
{
    myDb = db_connect(DB_HOST, DB_NAME, DB_USER, __USE_MYSQL__);
}

//获取上一次数据库返回其中的信息，可以指定行，如果不指定行，传回所有数据 ---- 0为多查询，1为单查询
mixed obtain_message(int i)
{
    mixed res;
    mixed fileds;

    if (undefinedp(line) || !line)
    {
        return 0;
    }

    if (stringp(line))
    {
        return line;
    }

    if (i == 0)
    {
        mapping data = ([]);

        fileds = db_fetch(myDb, 0);
        for (i = 1; i <= line; i++)
        {
            res = db_fetch(myDb, i);
            data = allocate_mapping(fileds, res); //以主键作为key返回哈希表
        }

        return data;
    }

    res = db_fetch(myDb, i);

    if (arrayp(res) && sizeof(res) == 1)
    {
        res = res[0];
    }

    return res;
}

int obtain_line()
{
    return line;
}