How to run a database script file from Delphi?

Question

I want to do the following. 1) Create a database. 2) Run a script when creates tables, stored procedures, etc. (this script is created by SMS 'generate scripts' option)

I found the following code: http://www.delphipages.com/forum/showthread.php?t=181685 and modified it to this:

try

 ADOQuery.ConnectionString := 'Provider=SQLOLEDB.1;Password=' + 

edtPassword.Text + ';Persist Security Info=True;User ID=' + edtUser.Text + ';Initial Catalog=master;Data Source=' + edtServerName.Text;

 ADOQuery.SQL.Clear; ADOQuery.SQL.Text := 'create DataBase ' + edtWebDBName.Text; ADOQuery.ExecSQL; // should check existance of database ADOWeb.Connected := false; ADOWeb.ConnectionString := 'Provider=SQLOLEDB.1;Password=' + 

edtPassword.Text + ';Persist Security Info=True;User ID=' + edtUser.Text + ';Initial Catalog=' + edtWebDBName.Text + ';Data Source=' + edtServerName.Text; ADOWeb.Connected := true;

 ADOQuery.Connection := ADOWeb; ADOQuery.SQL.Clear; ADOQuery.SQL.LoadFromFile(edtScriptFileName.Text); ADOQuery.ExecSQL; except 

This works up until the point of running the script file. Then it generates an exception: Incorrect Syntax near "GO". If i run the script in SMS on the newly created DB, it is fine. Is this issue due to running more than one SQL command at once (the script is essentially a long list of command/GO statements? How to get around it?

Oh also as a bonus, any thoughts on a quick check to see if the new database actually exists before sending a script to it? (Or is it not necessary since if the create fails it will generate exception?)

Answer 1

Rob the GO statement is not recognized by ADO, so you must remove from your script before execute.

Now to check if a database exist you can execute a query like this

select COUNT(*) from sys.databases where name='yourdatabasename'

check this very basic sample

assume which you have a script like this

CREATE TABLE Dummy.[dbo].tblUsers(ID INT, UserName VARCHAR(50))
GO
INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (1, 'Jill')
GO
INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (2, 'John')
GO
INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (3, 'Jack')
GO

Now to execute this sentence you can do something like this

const
//in this case the script is inside of a const string but can be loaded from a file as well
Script=
'CREATE TABLE Dummy.[dbo].tblUsers(ID INT, UserName VARCHAR(50)) '+#13#10+
'GO '+#13#10+
'INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (1, ''Jill'') '+#13#10+
'GO '+#13#10+
'INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (2, ''John'') '+#13#10+
'GO '+#13#10+
'INSERT INTO Dummy.[dbo].tblUsers (ID, UserName) VALUES (3, ''Jack'') '+#13#10+
'GO ';

var
  DatabaseExist : Boolean;
  i             : Integer;
begin
  try
    //check the connection
     if not ADOConnection1.Connected then
      ADOConnection1.Connected:=True;
      //make the query to check if the database called Dummy exist  
      ADOQuery1.SQL.Add(Format('select COUNT(*) from sys.databases where name=%s',[QuotedStr('Dummy')]));
      ADOQuery1.Open;
      try
       //get the returned value, if is greater than 0 then exist 
       DatabaseExist:=ADOQuery1.Fields[0].AsInteger>0;
      finally
       ADOQuery1.Close;
      end;


      if not DatabaseExist then
      begin
       //create the database if not exist
       ADOQuery1.SQL.Text:=Format('Create Database %s',['Dummy']);
       ADOQuery1.ExecSQL;
       ADOQuery1.Close;

       //load the script, remember can be load from a file too  
       ADOQuery1.SQL.Text:=Script;
       //parse the script to remove the GO statements
        for i := ADOQuery1.SQL.Count-1 downto 0 do
          if StartsText('GO',ADOQuery1.SQL[i]) then
           ADOQuery1.SQL.Delete(i);
       //execute the script
       ADOQuery1.ExecSQL;
       ADOQuery1.Close;
      end;
  except
      on E:Exception do
        ShowMessage(E.Message);
  end;

end;

Answer 2

That GO means the end of a batch only for certain Microsoft utilities, it's not a proper T-SQL statement. Try to delete each occurance of GO in your script and then execute it. That GO will perform ADOQuery.ExecSQL for you at the end of your script.

And to your second question; you can use eg SQL function DB_ID to check if your DB exists (you have to be on the same server of course). This function returns the database ID; otherwise NULL, so if the following SQL statement returns NULL your database creation failed.

ADOQuery.SQL.Text := 'SELECT DB_ID(' + edtWebDBName.Text + ')';
ADOQuery.Open;

if ADO_Query.Fields[0].IsNull then
  ShowMessage('Database creation failed');

Answer 3

Scripts may contain much more than SQL DDL/DML commands. They can contain variables, small blocks of code, transaction management statement. Usually there are more than one statement, separated by a terminator (a semicolon, the Oracle slash, MSSQL GO, etc, depending on the database you're using and its script syntax). To execute a script properly you have to parse the input file, separate each command, and feed it to the database properly. You can look for library to do that (there are some, IIRC), or yo can try to use the MS SQL command line tool to feed the script via it.