unit _libmysq;
{This is a more complete unit to interface with MySQL Server from Delphi
This work was started by by Blestan Tabakov. I have included the rest of the
functionality in libmysql.dll.
Delphi 3 Interface to LibMYSQL.dll
June 1998
Bob Silva bsilva@umesd.k12.or.us
To find out more on this get the C API docs from
www.tcx.se (makers of MySQL)}
{TODO: Implement as a VCL I dont think I have the knowledge to make it use Delphis
data controls but Ill look into it, I dont think the component will be too hard to
implement in the near future}
interface
const
mysql_errmsg_size=200;
MYSQL_PORT=3306;
LOCAL_HOST='localhost';
MYSQL_UNIX_ADDR='/tmp/mysql.sock';
NAME_LEN=64;
PROTOCOL_VERSION=10;
MYSQL_SERVER_VERSION='3.21.18-beta';
FRM_VER=6;
MYSQL_VERSION_ID=32115;
field_type_decimal=0;
field_type_tiny=1;
field_type_short=2;
field_type_long=3;
field_type_float=4;
field_type_double=5;
field_type_null=6;
field_type_timestamp=7;
field_type_longlong=8;
field_type_int24=9;
field_type_date=10;
field_type_time=11;
field_type_datetime=12;
field_type_enum=247;
field_type_set=248;
field_type_tiny_blob=249;
field_type_medium_blob=250;
field_type_long_blob=251;
field_type_blob=252;
field_type_var_string=253;
field_type_string=254;
type
enum_field_types=byte;
my_bool= shortint;
gptr= pchar;
socket= word;
mysql_status=(mysql_status_ready,mysql_status_get_result,mysql_status_use_result);
pused_mem=^used_mem;
used_mem=record
next:pused_mem;
left,size: Cardinal;
end;
err_proc=procedure;
pmem_root=^mem_root;
mem_root=record
free,used:pused_mem;
min_malloc,block_size: Cardinal;
error_handler:err_proc;
end;
net=record
fd: socket;
fcntl: integer;
buff,buff_end,write_pos: pchar;
last_error:array[01..mysql_errmsg_size] of char;
last_errno,max_packet,timeout,pkt_vnr: integer;
error,return_errno: my_bool;
end;
pmysql_field=^mysql_field;
mysql_field=record
name,table,def: pchar;
_type: enum_field_types;
length,max_length,flags,decimals: Cardinal;
end;
mysql_field_offset= Cardinal;
(*************HELP HERE IF YOU CAN*************)
{The C def for this is: typedef byte **MYSQL_ROW;
Blestan originally used the array struct below, but I could not get it to
work like that.
Blestan Code: mysql_row=array[00..$ffff div sizeof(pchar)] of pchar;
My def of a smaller array seems to solve the problem, but if you were to return
a very large result set, Im sure it will AV. So if you can translate the C Code:
Earlier in code: typedef char byte;
typedef byte **MYSQL_ROW; into an adequate Delphi type then please do and let
me know how you did it. I could get it to return rows using mysql_row: ^PChar; but
I couldnt figure out how to index into it like that.}
pmysql_row=^mysql_row;
mysql_row= array[00..$ff] of pchar;
(*********************************************)
pmysql_rows=^mysql_rows;
mysql_rows=record
next: pmysql_rows;
data: pmysql_row;
end;
mysql_row_offset= pmysql_rows;
pmysql_data= ^mysql_data;
mysql_data= record
rows, fields: Cardinal;
data: pmysql_rows;
alloc: mem_root;
end;
pmysql=^mysql;
mysql= record
_net: net;
host,user,passwd,
unix_socket,
server_version,
host_info,
info,db: pchar;
port,client_flag,server_capabilities,
protocol_version,field_count: Cardinal;
thread_id, affected_rows, insert_id, extra_info:longint;
status: mysql_status;
fields: pmysql_field;
field_alloc: mem_root;
free_me, reconnect: my_bool;
end;
pmysql_res=^mysql_res;
mysql_res= record
row_count: longint;
field_count, current_field: Word;
fields: pmysql_field;
data: pmysql_data;
data_cursor:pmysql_rows;
field_alloc:mem_root;
row: mysql_row;
current_row: pmysql_row;
lengths: ^Word;
handle: ^mysql;
eof: my_bool;
end;
const thelib='libmysql.dll';
(*********ALL functions are working unless stated otherwise*************)
{If you can figure why why one of the ones marked bad is not working, please
send me the code to implement it properly}
function mysql_connect( _mysql: pmysql; const host,user,passwd:pchar):pmysql;stdcall;
{Non-functional: dont know why yet: I think you can do without it for now}
function mysql_real_connect(_mysql: pmysql; const host, user, passwd, db:pchar;
port:Cardinal; unix_socket:PChar;clientflag:Cardinal):pmysql;stdcall;
procedure mysql_close( _mysql: pmysql); stdcall;
function mysql_select_db(_mysql:pmysql;const DB: pchar):integer; stdcall;
function mysql_query(_mysql:pmysql;const query: pchar):integer;stdcall;
{Real Query not implemented in current version of libmysql.dll (timestamp:353be33a)}
function mysql_real_query(_mysql:pmysql;const query: pchar;length: Cardinal):integer;stdcall;
function mysql_create_db(_mysql:pmysql; const DB:PChar):integer;stdcall;
function mysql_drop_db(_mysql:pmysql; const DB:PChar):integer;stdcall;
function mysql_shutdown(_mysql: pmysql): Integer; stdcall;
{Although undocumented, I believe this is to reload the permissions table;
documentation calls for a reload function which there is none in libmysql.dll,
so I think this may be a replacement, it takes a Cardinal for options but I cant find out
what those options are since its not documented}
function mysql_refresh(_mysql:pmysql; refresh_options: Cardinal):integer;stdcall;
function mysql_kill(_mysql:pmysql; pid:longint):integer;stdcall;
function mysql_stat(_mysql:pmysql):pchar; stdcall;
function mysql_get_server_info(_mysql:pmysql):PChar;stdcall;
function mysql_get_client_info:PChar;stdcall;
function mysql_get_host_info(_mysql:pmysql):PChar;stdcall;
function mysql_get_proto_info(_mysql:pmysql):Cardinal;stdcall;
function mysql_list_dbs(_mysql:pmysql;wild: pchar):pmysql_res; stdcall;
function mysql_list_tables(_mysql: pmysql; const wild: pchar):pmysql_res; stdcall;
function mysql_list_fields(_mysql: pmysql;const table,wild: pchar):pmysql_res; stdcall;
function mysql_list_processes(_mysql: pmysql):pmysql_res; stdcall;
function mysql_store_result(_mysql:pmysql):pmysql_res; stdcall;
function mysql_use_result(_mysql:pmysql):pmysql_res;stdcall;
procedure mysql_free_result(result:pmysql_res); stdcall;
procedure mysql_data_seek(result:pmysql_res; offset:Cardinal); stdcall;
{Row seek is probably functional if I knew how to test it;
I think its a matter of saving a particular row pointer in a mysql_row_offset struct;
then later make a call to row_seek to restore the data_cursor to that row;
then a fetch_row will return the next row after that???? I have no need for it so you tell me}
function mysql_row_seek(result:pmysql_res; row:mysql_row_offset):mysql_row_offset;stdcall;
{Field Seek is not implemented in current version of libmysql.dll(timestamp:353be33a)}
function mysql_field_seek(result:pmysql_res;offset:mysql_field_offset):mysql_field_offset;stdcall
function mysql_fetch_row(result:pmysql_res):pmysql_row;stdcall;
{I dont think fetch_length is working properly because of the way that I set up the MYSQL_ROW array}
function mysql_fetch_lengths(result:pmysql_res):Cardinal;stdcall;
function mysql_fetch_field(handle: pmysql_res):pmysql_field; stdcall;
implementation
function mysql_connect( _mysql: pmysql; const host,user,passwd:pchar):pmysql;stdcall;external thelib;
function mysql_real_connect(_mysql: pmysql; const host, user, passwd, db:pchar;
port:Cardinal; unix_socket:PChar;clientflag:Cardinal):pmysql;stdcall;external thelib;
procedure mysql_close( _mysql: pmysql); stdcall;external thelib;
function mysql_select_db(_mysql:pmysql;const DB: pchar):integer; stdcall;external thelib;
function mysql_query(_mysql:pmysql;const query: pchar):integer;stdcall;external thelib;
function mysql_real_query(_mysql:pmysql;const query: pchar;length: Cardinal):integer;stdcall;external thelib;
function mysql_create_db(_mysql:pmysql; const DB:PChar):integer;stdcall;external thelib;
function mysql_drop_db(_mysql:pmysql; const DB:PChar):integer;stdcall;external thelib;
function mysql_shutdown(_mysql: pmysql): Integer; stdcall;external thelib;
function mysql_refresh(_mysql:pmysql; refresh_options: Cardinal):integer;stdcall;external thelib;
function mysql_kill(_mysql:pmysql; pid:longint):integer;stdcall;external thelib;
function mysql_stat(_mysql:pmysql):pchar; stdcall;external thelib;
function mysql_get_server_info(_mysql:pmysql):PChar;stdcall;external thelib;
function mysql_get_client_info:PChar;stdcall;external thelib;
function mysql_get_host_info(_mysql:pmysql):PChar;stdcall;external thelib;
function mysql_get_proto_info(_mysql:pmysql):Cardinal;stdcall;external thelib;
function mysql_list_dbs(_mysql:pmysql;wild: pchar):pmysql_res; stdcall;external thelib;
function mysql_list_tables(_mysql: pmysql; const wild: pchar):pmysql_res; stdcall;external thelib;
function mysql_list_fields(_mysql: pmysql;const table,wild: pchar):pmysql_res; stdcall;external thelib;
function mysql_list_processes(_mysql: pmysql):pmysql_res; stdcall;external thelib;
function mysql_store_result(_mysql:pmysql):pmysql_res; stdcall;external thelib;
function mysql_use_result(_mysql:pmysql):pmysql_res;stdcall;external thelib;
procedure mysql_free_result(result:pmysql_res); stdcall;external thelib;
procedure mysql_data_seek(result:pmysql_res; offset:Cardinal); stdcall;external thelib;
function mysql_row_seek(result:pmysql_res; row:mysql_row_offset):mysql_row_offset;stdcall;external thelib;
function mysql_field_seek(result:pmysql_res;offset:mysql_field_offset):mysql_field_offset;stdcall;external thelib;
function mysql_fetch_row(result:pmysql_res):pmysql_row;stdcall;external thelib;
function mysql_fetch_lengths(result:pmysql_res):Cardinal;stdcall;external thelib;
function mysql_fetch_field(handle: pmysql_res):pmysql_field; stdcall;external thelib;
end.
og selve programmet :
unit connect;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, _libmysq;
type
TForm1 = class(TForm)
GroupBox1: TGroupBox;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
edtHostname: TEdit;
edtUsername: TEdit;
edtPasswd: TEdit;
edtDatabase: TEdit;
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
procedure Button3Click(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure Button1Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
mysqlrec: mysql; //Global mysql struct
connected: Integer; //Global var to keep track of whether we are connected
implementation
{$R *.DFM}
procedure TForm1.Button3Click(Sender: TObject);
begin
Close;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
if connected = 1 then
{Close the Database Connection}
mysql_close(@mysqlrec);
end;
procedure TForm1.Button1Click(Sender: TObject);
var
host, user, passwd: String;
begin
host:= edtHostname.Text;
user:= edtUsername.Text;
passwd:= edtPasswd.Text;
{Connect to server}
mysql_connect(@mysqlrec, PChar(host), PChar(user), PChar(passwd));
if mysqlrec.status = mysql_status_ready then
begin
ShowMessage ('Successfully connected to the Database.');
connected:= 1; //keep track of connection
Button2.Enabled:= true;
Button4.Enabled:= true;
Button1.Enabled:= false;
end
else
ShowMessage ('Unable to connect to database.');
end;
procedure TForm1.Button4Click(Sender: TObject);
var
db: String;
retval: Integer;
begin
db:= edtDatabase.Text;
retval:= mysql_select_db(@mysqlrec, PChar(db));
if retval <> 0 then
ShowMessage('Error attaching to: ' + db)
else
ShowMessage('Successfully attached to ' + db);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
mysql_close(@mysqlrec);
ShowMessage('Disconnected from the database.');
Button1.Enabled:= true;
Button2.Enabled:= false;
Button4.Enabled:= false;
connected:= 0;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
connected:= 0; //We are not connected to the server
{Disable the disconnect button till connected}
Button2.Enabled:= false;
{Disable the attach to db button till connected}
Button4.Enabled:= false;
end;
end.
koden12
