Článek
10/01/2010

sp_OAMethod (Transact-SQL)

Calls a method of an OLE object.

Topic link icon Transact-SQL Syntax Conventions

Syntax

sp_OAMethodobjecttoken, methodname
    [ , returnvalue OUTPUT ] 
    [ , [ @parametername = ] parameter [ OUTPUT ] [ ...n ] ]

Arguments

objecttoken
Is the object token of an OLE object that was previously created by using sp_OACreate.
methodname
Is the method name of the OLE object to call.
returnvalue OUTPUT
Is the return value of the method of the OLE object. If specified, it must be a local variable of the appropriate data type.

If the method returns a single value, either specify a local variable for returnvalue, which returns the method return value in the local variable, or do not specify returnvalue, which returns the method return value to the client as a single-column, single-row result set.

If the method return value is an OLE object, returnvalue must be a local variable of data type int. An object token is stored in the local variable, and this object token can be used with other OLE Automation stored procedures.

When the method return value is an array, if returnvalue is specified, it is set to NULL.

An error is raised when any one of the following occurs:
- returnvalue is specified, but the method does not return a value.
- The method returns an array with more than two dimensions.
- The method returns an array as an output parameter.
[ @parametername**=** ] parameter[ OUTPUT ]
Is a method parameter. If specified, parameter must be a value of the appropriate data type.

To obtain the return value of an output parameter, parameter must be a local variable of the appropriate data type, and OUTPUT must be specified. If a constant parameter is specified, or if OUTPUT is not specified, any return value from an output parameter is ignored.

If specified, parametername must be the name of the Microsoft Visual Basic named parameter. Note that @*parametername *is not a Transact-SQL local variable. The at sign (@**) is removed, and parametername* *is passed to the OLE object as the parameter name. All named parameters must be specified after all positional parameters are specified.
n
Is a placeholder indicating that multiple parameters can be specified.

Note

@parametername can be a named parameter because it is part of the specified method and is passed through to the object. The other parameters for this stored procedure are specified by position, not name.

Return Code Values

0 (success) or a nonzero number (failure) that is the integer value of the HRESULT returned by the OLE Automation object.

For more information about HRESULT Return Codes, OLE Automation Return Codes and Error Information.

Result Sets

If the method return value is an array with one or two dimensions, the array is returned to the client as a result set:

A one-dimensional array is returned to the client as a single-row result set with as many columns as there are elements in the array. In other words, the array is returned as (columns).
A two-dimensional array is returned to the client as a result set with as many columns as there are elements in the first dimension of the array and with as many rows as there are elements in the second dimension of the array. In other words, the array is returned as (columns, rows).

When a property return value or method return value is an array, sp_OAGetProperty or sp_OAMethod returns a result set to the client. (Method output parameters cannot be arrays.) These procedures scan all the data values in the array to determine the appropriate SQL Server data types and data lengths to use for each column in the result set. For a particular column, these procedures use the data type and length required to represent all data values in that column.

When all data values in a column share the same data type, that data type is used for the whole column. When data values in a column are of different data types, the data type of the whole column is chosen based on the following chart.

	int	float	money	datetime	varchar	nvarchar
int	int	float	money	varchar	varchar	nvarchar
float	float	float	money	varchar	varchar	nvarchar
money	money	money	money	varchar	varchar	nvarchar
datetime	varchar	varchar	varchar	datetime	varchar	nvarchar
varchar	varchar	varchar	varchar	varchar	varchar	nvarchar
nvarchar	nvarchar	nvarchar	nvarchar	nvarchar	nvarchar	nvarchar

Remarks

You can also use sp_OAMethod to get a property value.

Permissions

Requires membership in the sysadmin fixed server role.

Examples

A. Calling a method

The following example calls the Connect method of the previously created SQLServer object.

EXEC @hr = sp_OAMethod @object, 'Connect', NULL, 'my_server',
    'my_login', 'my_password'
IF @hr <> 0
BEGIN
   EXEC sp_OAGetErrorInfo @object
    RETURN
END

B. Getting a property

The following example gets the HostName property (of the previously created SQLServer object) and stores it in a local variable.

DECLARE @property varchar(255)
EXEC @hr = sp_OAMethod @object, 'HostName', @property OUT
IF @hr <> 0
BEGIN
   EXEC sp_OAGetErrorInfo @object
    RETURN
END
PRINT @property

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