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ThoseBug

asked on

Exists SQL Server

my user can input some like this   SQLDatabaseServer.DataBaseName in a string variable
example
               dbvar :=  SQL-Server.Employee List  
first i need transform dbvar in a correct sql syntax   ----> dbvar := [SQL-Server].[Employee List]

now the big problem is how can i know if [SQL-Server] exists on my lan...

i need execute this
           
doSQL('select name from '+ dbvar+'.dbo.sysobjects where name='+quotedstr('MyTableName'))='MyTableName'

but i have errors like Could not find server 'SQL-Server' or Incorrect syntax near '-' if my dbvar still with SQL-Server

thank you.

Avatar of Peter_
Peter_

Could be simply that SQL is a reserved word?

According to

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_ra-rz_9oj7.asp

It is, at least in ODBC.

Try naming the server as something else, maybe that will do it?
hi,

first of all, you have to know all the connection parameters for the SQL Server.
if you know them, you can do:

function checkSQL(aServerName: string; aConnectionString: string): boolean;
var
  conn : TADOConnection;
begin
  Result := False;
  conn := TADOConnection.Create(nil);
  conn.ConnectionString := aConnectionString;
  conn.CommandTimeout := 2;
  try
    try
      conn.Open;
      Result := True;
    except
      ShowMessage('Cannot connect to server: ' + aServerName);
    end;
  finally
    if conn.Connected then
      conn.Close;
  end;
end;

a connectionstring should look like:
'Provider=SQLOLEDB.1;Persist Security Info=True;Data Source=***;User ID=***;Password=***'
where:
Data Source = SQL ServerName
User ID = SQL login
Password = SQL password

Bogdan
To check if [SQL-Server] exists on your lan, you can check that if on that server, the SQL Server service is running.

You can use this line of code:
  if serviceRunning('\\'+SQLServer,'mssqlserver') then

putting these 3 little procedures into your source:

//-------------------------------------
// get service status
//
// return status code if successful
// -1 if not
//
// return codes:
//   SERVICE_STOPPED
//   SERVICE_RUNNING
//   SERVICE_PAUSED
//
// following return codes
// are used to indicate that
// the service is in the
// middle of getting to one
// of the above states:
//   SERVICE_START_PENDING
//   SERVICE_STOP_PENDING
//   SERVICE_CONTINUE_PENDING
//   SERVICE_PAUSE_PENDING
//
// sMachine:
//   machine name, ie: \\SERVER
//   empty = local machine
//
// sService
//   service name, ie: Alerter
//
function ServiceGetStatus(
  sMachine,
  sService : string ) : DWord;
var
  //
  // service control
  // manager handle
  schm,
  //
  // service handle
  schs   : SC_Handle;
  //
  // service status
  ss     : TServiceStatus;
  //
  // current service status
  dwStat : Longint;
begin
  dwStat := -1;

  // connect to the service
  // control manager
  schm := OpenSCManager(
    PChar(sMachine),
    Nil,
    SC_MANAGER_CONNECT);

  // if successful...
  if(schm > 0)then
  begin
    // open a handle to
    // the specified service
    schs := OpenService(
      schm,
      PChar(sService),
      // we want to
      // query service status
      SERVICE_QUERY_STATUS);

    // if successful...
    if(schs > 0)then
    begin
      // retrieve the current status
      // of the specified service    
      if(QueryServiceStatus(
           schs,
           ss))then
      begin
        dwStat := ss.dwCurrentState;
      end;

      // close service handle
      CloseServiceHandle(schs);
    end;

    // close service control
    // manager handle
    CloseServiceHandle(schm);
  end;

  Result := dwStat;
end;

//-------------------------------------
// return TRUE if the specified
// service is running, defined by
// the status code SERVICE_RUNNING.
// return FALSE if the service
// is in any other state, including
// any pending states
//
function ServiceRunning(
  sMachine,
  sService : string ) : boolean;
begin
  Result := SERVICE_RUNNING =
    ServiceGetStatus(
      sMachine, sService );
end;


//-------------------------------------
// return TRUE if the specified
// service was stopped, defined by
// the status code SERVICE_STOPPED.
//
function ServiceStopped(
  sMachine,
  sService : string ) : boolean;
begin
  Result := SERVICE_STOPPED =
    ServiceGetStatus(
      sMachine, sService );
end;
Avatar of ThoseBug

ASKER

thank you roburobe
i have error in
 schs   : SC_Handle;
and others variables with a lot of errors...
If you are likely to have Enterprise manager (SQL Server tools) installed on the client machine, then you may activate any Enterprise Manager function or menu from within your appliction by using SQLNS and/or SQLDMO.

For a sample on how, see my answer to question below about making an SQL-Server backup:

https://www.experts-exchange.com/questions/20691981/How-to-use-delphi-to-backup-sqlserver-database.html

You could use this function to look for a database as an example:

function GetDBNameSpaceObject(
  const aDBName: String): SQLNamespaceObject;
var
  hServer,hDatabases,hDatabase:Integer;
begin
   Result:=nil;
   hServer:=FNameSpace.GetRootItem;
   hDatabases:=FNameSpace.GetFirstChildItem(hServer,SQLNSOBJECTTYPE_DATABASES,'');
   hDatabase:=FNameSpace.GetFirstChildItem(hDatabases,SQLNSOBJECTTYPE_DATABASE,aDBName);
   Result:=FNameSpace.GetSQLNameSpaceObject(hDatabase);
end;

Once imported, these units (SQLNS, SQLDMO) give access to lots of powerful easy to use functions (like browsing all servers in your network).

I don't have sql-server installed where I'm at right now, so I cant provide a full sample for this exact problem. But if you have been using the tools before, then just browse the units and you figure it out. The only downside is that the sql server tools will have to be installed on the client machine or it wont work.
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Computer101
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