USE tempdb
GO 

CREATE PROCEDURE [dbo].[Create_if_not_exist] @proc_text NVARCHAR(max), @proc_name NVARCHAR(1000) 
AS 
    IF Object_id('tempdb.dbo.##t', 'U') IS NOT NULL 
      DROP TABLE ##t; 

    DECLARE @counter          INT, 
            @full_text        NVARCHAR(max) ='', 
            @proc_text_target NVARCHAR(max), 
            @sqlexectext      NVARCHAR(1000) 

    SET @sqlexectext= 
    N'set @counter  = (select COUNT(*) FROM syscomments where id = object_id(''' + @proc_name + '''))' 

    EXEC Sp_executesql @sqlexectext, 
						N'@counter int OUTPUT', 
						@counter=@counter output 

    EXEC( 
	'select  row_number() OVER(ORDER BY colid desc) as col_id , [text] into ##t FROM syscomments where id = object_id(''' + @proc_name + ''')') 

    IF @counter > 1 
      BEGIN 
          WHILE @counter != 0 
            BEGIN 
                SET @full_text=@full_text 
                               + (SELECT [text] FROM   ##t WHERE  col_id = @counter)
                SET @counter=@counter - 1 
            END 

          SET @proc_text_target=(SELECT Rtrim(Ltrim(@full_text))) 
      END 
    ELSE 
      SET @proc_text_target = (SELECT Rtrim(Ltrim(text)) 
                               FROM   syscomments 
                               WHERE  id = Object_id(@proc_name)) 

    IF @proc_text != @proc_text_target 
        OR @proc_text_target IS NULL 
      BEGIN 
          EXEC ('
	  IF OBJECT_ID('''+@proc_name+''', ''P'') IS NOT NULL 
	  drop procedure ' + @proc_name) 

          EXEC (@proc_text) 

		   PRINT 'Пересоздал или создал процедуру ' + @proc_name
      END; 
GO

EXEC [dbo].[Create_if_not_exist] 
'CREATE PROCEDURE [dbo].[MyGetdate] AS SELECT GETDATE() AS [Дата попойки]', '[dbo].[MyGetdate]'
GO 
EXEC [dbo].[MyGetdate]
GO 
EXEC [dbo].[Create_if_not_exist] 
'CREATE PROCEDURE [dbo].[MyGetdate] AS SELECT GETDATE() AS [Дата запоя]', '[dbo].[MyGetdate]'
GO 
EXEC [dbo].[MyGetdate]
GO 
EXEC [dbo].[Create_if_not_exist] 
'CREATE PROCEDURE [dbo].[MyGetdate] AS SELECT GETDATE() AS [Дата запоя]', '[dbo].[MyGetdate]'
GO 
EXEC [dbo].[MyGetdate]
GO 
EXEC [dbo].[Create_if_not_exist] 
'CREATE PROCEDURE [dbo].[MyGetdate] AS SELECT GETDATE() AS [Дата бодуна]', '[dbo].[MyGetdate]'
GO 
EXEC [dbo].[MyGetdate]
GO