In this blog, I have shown the process of calling web services through a stored procedure in SQL Server database. Also, I have explained how to call a stored procedure with a SOAP Envelope.

Step 1
Create a stored procedure in your SQL Server.
  CREATE proc [dbo].[spHTTPRequest]    
        @URI varchar(2000) = 'http://localhost:55253/',         
        @methodName varchar(50) = 'Get',    
        @requestBody varchar(8000) = '',    
        @SoapAction varchar(255),    
        @UserName nvarchar(100), -- Domain\UserName or UserName    
        @Password nvarchar(100),    
        @responseText varchar(8000) output   
  as   
  SET NOCOUNT ON   
  IF    @methodName = ''   
  BEGIN   
        select FailPoint = 'Method Name must be set'   
        return   
  END   
  set   @responseText = 'FAILED'   
  DECLARE @objectID int   
  DECLARE @hResult int   
  DECLARE @source varchar(255), @desc varchar(255)    
  EXEC @hResult = sp_OACreate 'MSXML2.ServerXMLHTTP', @objectID OUT   
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
                    source = @source,    
                    description = @desc,    
                    FailPoint = 'Create failed',    
                    MedthodName = @methodName    
        goto destroy    
        return   
  END   
  -- open the destination URI with Specified method    
  EXEC @hResult = sp_OAMethod @objectID, 'open', null, @methodName, @URI, 'false', @UserName, @Password   
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'Open failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  -- set request headers    
  EXEC @hResult = sp_OAMethod @objectID, 'setRequestHeader', null, 'Content-Type', 'text/xml;charset=UTF-8'   
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'SetRequestHeader failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  -- set soap action    
  EXEC @hResult = sp_OAMethod @objectID, 'setRequestHeader', null, 'SOAPAction', @SoapAction    
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'SetRequestHeader failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  declare @len int   
  set @len = len(@requestBody)    
  EXEC @hResult = sp_OAMethod @objectID, 'setRequestHeader', null, 'Content-Length', @len    
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'SetRequestHeader failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  /*   
  -- if you have headers in a table called RequestHeader you can go through them with this   
  DECLARE @HeaderKey varchar(500), @HeaderValue varchar(500)   
  DECLARE RequestHeader CURSOR  
  LOCAL FAST_FORWARD   
  FOR  
        SELECT      HeaderKey, HeaderValue   
        FROM RequestHeaders   
        WHERE       Method = @methodName   
  OPEN RequestHeader   
  FETCH NEXT FROM RequestHeader   
  INTO @HeaderKey, @HeaderValue   
  WHILE @@FETCH_STATUS = 0   
  BEGIN  
        --select @HeaderKey, @HeaderValue, @methodName   
        EXEC @hResult = sp_OAMethod @objectID, 'setRequestHeader', null, @HeaderKey, @HeaderValue   
        IF @hResult <> 0   
        BEGIN  
              EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT  
              SELECT      hResult = convert(varbinary(4), @hResult),   
                    source = @source,   
                    description = @desc,   
                    FailPoint = 'SetRequestHeader failed',   
                    MedthodName = @methodName   
              goto destroy   
              return  
        END  
        FETCH NEXT FROM RequestHeader   
        INTO @HeaderKey, @HeaderValue   
  END  
  CLOSE RequestHeader   
  DEALLOCATE RequestHeader   
  */    
  -- send the request    
  EXEC @hResult = sp_OAMethod @objectID, 'send', null, @requestBody    
  IF    @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'Send failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  declare @statusText varchar(1000), @status varchar(1000)    
  -- Get status text    
  exec sp_OAGetProperty @objectID, 'StatusText', @statusText out   
  exec sp_OAGetProperty @objectID, 'Status', @status out   
  select @status, @statusText, @methodName    
  -- Get response text    
  exec sp_OAGetProperty @objectID, 'responseText', @responseText out   
  IF @hResult <> 0    
  BEGIN   
        EXEC sp_OAGetErrorInfo @objectID, @source OUT, @desc OUT   
        SELECT      hResult = convert(varbinary(4), @hResult),    
              source = @source,    
              description = @desc,    
              FailPoint = 'ResponseText failed',    
              MedthodName = @methodName    
        goto destroy    
        return   
  END   
  destroy:    
        exec sp_OADestroy @objectID    
  SET NOCOUNT OFF   
      
  GO   


The Stored Procedure takes the following parameters.
  @URI: the URI of the web service
  @MethodName: this would be ‘GET’ or ‘POST’
  @RequestBody: this is the SOAP xml that you want to send
  @SoapAction: this the operation that you want to call on your service
  @UserName: NT UserName if your web service requires authentication
  @Password: the password if using NT Authentication on the web service
  @ResponseText: this is an out parameter that contains the response from the web service


Step 2
Make the setting in SQL for it.
  Use master 
  sp_configure 'show advanced options', 1  
   
  GO  
  RECONFIGURE;  
  GO  
  sp_configure 'Ole Automation Procedures', 1  
  GO  
  RECONFIGURE;  
  GO  
  sp_configure 'show advanced options', 1  
  GO  
  RECONFIGURE; 


Step 3

Call the stored procedure (Here is a sample call to my service).
  declare @xmlOut varchar(8000) 
  Declare @RequestText as varchar(8000); 
  set @RequestText= 
  '<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tem="http://tempuri.org/"> 
     <soapenv:Header/> 
     <soapenv:Body> 
        <tem:CreateOrder> 
           <!--Optional:--> 
           <tem:OrderRequest> 
              <tem:OrderId>200</tem:OrderId> 
              <!--Optional:--> 
              <tem:OrderName>something</tem:OrderName> 
           </tem:OrderRequest> 
        </tem:CreateOrder> 
     </soapenv:Body> 
  </soapenv:Envelope>' 
  exec spHTTPRequest 
  'http://localhost/testwebservices/helloworldservice.asmx', 
  'POST', 
  @RequestText, 
  'http://tempuri.org/CreateOrderForMe',   -- this is your SOAPAction: 
  '', '', @xmlOut out 
  select @xmlOut  


Make sure your SOAP action is correct. Copy this action from your services. It will show up when your service is RUN.