First expression about UNPIOVT(列名转列值Column convert to Row)

Normally, we select as below

SELECT @@SPID AS SPID,
CASE quoted_identifier
WHEN 1 THEN 'ON' ELSE 'OFF' END QUOTED_IDENTIFIER,
CASE arithabort
WHEN 1 THEN 'ON' ELSE 'OFF' END ARITHABORT,
CASE ansi_null_dflt_on
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_NULL_DFLT_ON,
CASE ansi_defaults
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_DEFAULTS ,
CASE ansi_warnings
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_WARNINGS,
CASE ansi_padding
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_PADDING,
CASE ansi_nulls
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_NULLS,
CASE concat_null_yields_null
WHEN 1 THEN 'ON' ELSE 'OFF' END CONCAT_NULL_YIELDS_NULL
FROM sys.aaa
WHERE session_id = @@SPID

Then we will get:



Let us schedule a step to convert Column Name to Row Value

SELECT SPID,VALUE,ANSI_SETTING
FROM (
SELECT @@SPID AS SPID,
CASE quoted_identifier
WHEN 1 THEN 'ON' ELSE 'OFF' END QUOTED_IDENTIFIER,
CASE arithabort
WHEN 1 THEN 'ON' ELSE 'OFF' END ARITHABORT,
CASE ansi_null_dflt_on
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_NULL_DFLT_ON,
CASE ansi_defaults
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_DEFAULTS ,
CASE ansi_warnings
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_WARNINGS,
CASE ansi_padding
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_PADDING,
CASE ansi_nulls
WHEN 1 THEN 'ON' ELSE 'OFF' END ANSI_NULLS,
CASE concat_null_yields_null
WHEN 1 THEN 'ON' ELSE 'OFF'
END CONCAT_NULL_YIELDS_NULL
FROM sys.aaaa
WHERE session_id = @@SPID
) P
UNPIVOT
(
VALUE FOR ANSI_SETTING IN
(
QUOTED_IDENTIFIER,ARITHABORT,ANSI_NULL_DFLT_ON,
ANSI_DEFAULTS,ANSI_WARNINGS,
ANSI_PADDING,ANSI_NULLS,CONCAT_NULL_YIELDS_NULL
)
) AS unpvt

The result as below:



Let us make a comparison



We need know that ‘UnPIOVT’ is not totally Inverse operations of ‘PIOVT’. It will not show the “NULL” value.