dbdriver.cpp

Shorthand是一个强大的脚本语言

#include "dbdriver.h"

// In the comments below is the skeleton for a new 
// ShortHand database driver:
/** 

class MyDriver : public ShhDbDriver
{
public:

    MyDriver() 
    {
    }

    void throwSQL(const char* format, ...)
    {
        va_list args; va_start(args, format);
        throw new ShhObjectException(format, args);
    }

    bool spi_RecognizeDriverName(const char* driverName)
    {
        string name(driverName);
        return name.ieq("SAMPLE");
    }

    const char* spi_GetDriverPrefix()
    {
        return "SAMPLE";
    }
    
    int spi_GetDriverDescription(string& driverDescription)
    {
        driverDescription = "MySQL Native Driver";
        return driverDescription.length();
    }
    
    virtual ShhDbHandle spi_Connect(const char* connString)
    {
        
        //  connection string has the following format:
        //  "driver={mysql}; database=yourdatabase;server=server;uid=username;pwd=password;option=16386;"
        //  and is stored in the "STRING" property

        if (!g_mysql_initialized)
        {
            mysql_init(&g_mysql);
            g_mysql_initialized = true;
        }

        string host, user, passwd, db, port, flags;

        char* tok_start = (char*)(connString);
        char* tok_end = NULL;
        while((tok_end = strchr(tok_start, ';')) != NULL)
        {
            *tok_end = '\0';
            char* name = tok_start;
            while(*name && isspace(*name)) name++;
       
            char* eq = strchr(tok_start, '=');
            if (eq != NULL)
            {
                *eq = '\0';
                char* value = eq + 1;
                while(*value && isspace(*value)) value++;
            
                if (stricmp(name, "server") == 0)
                    host = value;
                else if (stricmp(name, "database") == 0)
                    db = value;
                else if (stricmp(name, "uid") == 0)
                    user = value;
                else if (stricmp(name, "pwd") == 0)
                    passwd = value;
                else if (stricmp(name, "port") == 0)
                    port = value;
                else if (stricmp(name, "option") == 0)
                    flags = value;
            }
            tok_start = tok_end+1;
        }


        if (host.is_empty()) host = ".";

        MYSQL* session = mysql_real_connect(&g_mysql, 
            host.nv(), user.nv(), passwd.nv(), db.nv(), atoi(port), NULL, 0
        );

        if (session == NULL) 
            throw new ShhObjectException("MySQL connection to '%s' failed: %s", host.cstr(), mysql_error(&g_mysql));

        if (mysql_select_db(session, db) != 0)
        {
            char* e = mysql_error(session);
            mysql_close(session);
            throw new ShhObjectException("MySQL connection to '%s' (database '%s') failed: %s", host.cstr(), db.cstr(), e);
        }
        TRACE((5, "connected to MySQL\n"));
        return (ShhDbHandle) session;
    }

    virtual int spi_GetLastError(ShhDbHandle conn, string& message)
    {
        int code = mysql_errno((MYSQL*) conn);
        message = mysql_error((MYSQL*) conn);
        return code;
    }

    virtual void spi_Disconnect(ShhDbHandle conn)
    {
        mysql_close((MYSQL*) conn);
    }

    virtual ShhCursorHandle spi_PrepareSQL(ShhDbHandle conn, const char* sql)
    {
        return NULL; // "prepare" is not supported for MySQL
    }

    virtual void spi_CloseCursor(ShhCursorHandle cursor)
    {
        // TODO        
    }
    
    virtual void spi_CloseResult(ShhResultHandle resultSet)
    {
        if (resultSet != 0)
        {
            mysql_free_result((MYSQL_RES*) resultSet);
        }
    }

    virtual int spi_ExecuteImmediate(ShhDbHandle dbHandle, const char* sql)
    {
        if (mysql_real_query((MYSQL*)dbHandle, sql, strlen(sql)) != 0)
        {
            int code = mysql_errno((MYSQL*)dbHandle);
            const char* msg = mysql_error((MYSQL*)dbHandle);
	    throwSQL("SQL Query failed: MySQL error %d: %s", code, msg);
        }
        return 0;
    }

    virtual ShhResultHandle spi_ExecuteCursor(ShhDbHandle dbHandle, ShhCursorHandle cursor, const char* sql)
    {
        MYSQL* session = (MYSQL*) dbHandle;
        if (mysql_real_query(session, sql, strlen(sql)) != 0)
        {
            int code = mysql_errno(session);
            const char* msg = mysql_error(session);
	    throwSQL("SQL Query failed: MySQL error %d: %s", code, msg);
        }

        MYSQL_RES* result = mysql_store_result(session);
        if (result == NULL)
        {
            return 0;
        } 
        else
        {
            return (ShhResultHandle) result;
        }
    }
       

    virtual int spi_GetFieldCount(ShhResultHandle resultHandle)
    {
        if (resultHandle == 0) return 0;
        else return mysql_num_fields((MYSQL_RES*) resultHandle);
    }

    virtual int spi_GetRowCount(ShhResultHandle resultHandle)
    {
        if (resultHandle == 0) return 0;
        else return (int) mysql_num_rows((MYSQL_RES*) resultHandle);
    }

    virtual int spi_GetFieldName(ShhResultHandle resultHandle, int fieldNumber, string& fieldName)
    {
        if (resultHandle == 0) { fieldName = ""; return 0; }
        MYSQL_FIELD* field = mysql_fetch_field_direct((MYSQL_RES*) resultHandle, fieldNumber);
        fieldName = field->name;
        return fieldName.length();
    }

    virtual ShhRowHandle spi_Fetch(ShhResultHandle resultSet)
    {
        MYSQL_ROW row = mysql_fetch_row((MYSQL_RES*) resultSet);
        return (ShhRowHandle) row;
    }

    virtual int spi_GetStringValue(ShhResultHandle resultHandle, ShhRowHandle rowHandle, int fieldNumber, string& value)
    {
        MYSQL_ROW row = (MYSQL_ROW) rowHandle;
        unsigned long* lengths = mysql_fetch_lengths((MYSQL_RES*) resultHandle);
        unsigned int length = lengths[fieldNumber];
        if (length > 0)
        {
            value.set(row[fieldNumber], length);
        }
        else
        {
            value.clear();
        }
        return value.length();
    }

    virtual int spl_GetAffectedRows(ShhCursorHandle connection)
    {
        return (int) mysql_affected_rows((MYSQL*) connection);
    }

    virtual void spi_CloseRow(ShhRowHandle rowHandle)
    {
    }

};

ShhDbDriver* create_mysql_driver()
{
    return new MySQLDriver();
}
*/