The SQL Server Driver for PHP takes advantage of streams for retrieving large amounts of data. The topics in this section provide details about how to retrieve data as a stream.

The following steps summarize how to retrieve data as a stream:

1. Prepare and execute a Transact-SQL query with sqlsrv_query or the combination of sqlsrv_prepare/sqlsrv_execute.
   
2. Use sqlsrv_fetch to move to the next row in the result set.
   
3. Use sqlsrv_get_field to retrieve a field from the row. Specify that the data is to be retrieved as a stream by using SQLSRV_PHPTYPE_STREAM(<encoding>) as the third parameter in the function call. This table lists the constants used to specify encodings and their descriptions:
   

   SQLSRV Constant	Description
   SQLSRV_ENC_BINARY	Data is returned as a raw byte stream from the server without performing encoding or translation.
   SQLSRV_ENC_CHAR	Data is returned in 8-bit characters as specified in the code page of the Windows locale set on the system. Any multi-byte characters or characters that do not map into this code page are substituted with a single byte question mark (?) character.

Note:
Some data types are returned as streams by default. For more information, see Default PHP Data Types.