srv_parammaxlen (Extended Stored Procedure API)

Importante:
Questa funzionalità verrà rimossa in una delle prossime versioni di Microsoft SQL Server. Non utilizzare questa funzionalità in un nuovo progetto di sviluppo e modificare appena possibile le applicazioni in cui questa funzionalità viene utilizzata. Use CLR integration instead.

Returns the maximum data length of a remote stored procedure call parameter. This function has been superseded by the srv_paraminfo function.

Sintassi

int srv_parammaxlen (
SRV_PROC *
srvproc
,
int
n 
);

Arguments

• srvproc
  Is a pointer to the SRV_PROC structure that is the handle for a particular client connection (in this case, the handle that received the remote stored procedure call). The structure contains information the Extended Stored Procedure API library uses to manage communication and data between the application and the client.

• n
  Indicates the number of the parameter. The first parameter is 1.

Returns

The maximum length, in bytes, of the parameter data. If there is no nth parameter or if there is no remote stored procedure, it returns -1.

This function returns the following values, if the parameter is one of the following Microsoft SQL Server 2005 data types.

New data types	Input data length
BITN	NULL: 1 ZERO: 1 >=255: N/A <255: N/A
BIGVARCHAR	NULL: 255 ZERO: 255 >=255: 255 <255: 255
BIGCHAR	NULL: 255 ZERO: 255 >=255: 255 <255: 255
BIGBINARY	NULL: 255 ZERO: 255 >=255: 255 <255: 255
BIGVARBINARY	NULL: 255 ZERO: 255 >=255: 255 <255: 255
NCHAR	NULL: 255 ZERO: 255 >=255: 255 <255: 255
NVARCHAR	NULL: 255 ZERO: 255 >=255: 255 <255: 255
NTEXT	NULL: -1 ZERO: -1 >=255: -1 <255: -1

Osservazioni

Each remote stored procedure parameter has an actual and a maximum data length. For standard fixed-length data types that do not allow null values, the actual and maximum lengths are the same. For variable-length data types, the lengths can vary. For example, a parameter declared as varchar(30) can have data that is only 10 bytes long. The parameter's actual length is 10 and its maximum length is 30. The srv_parammaxlen function gets the maximum data length of a remote stored procedure. To obtain the actual length of a parameter, use srv_paramlen.

When a remote stored procedure call is made with parameters, the parameters can be passed either by name or by position (unnamed). If the remote stored procedure call is made with some parameters passed by name and some passed by position, an error occurs. The SRV_RPC handler is still called, but it appears as if there were no parameters, and srv_rpcparams returns 0.

Nota sulla protezione:
You should thoroughly review the source code of extended stored procedures, and you should test the compiled DLLs before you install them on a production server. For information about security review and testing, see this Microsoft Web site.

Vedere anche

Riferimento

srv_paraminfo (Extended Stored Procedure API)
srv_rpcparams (Extended Stored Procedure API)

Guida in linea e informazioni

Assistenza su SQL Server 2005