SQL Server/T-SQL Tutorial/System Tables Views/systypes

Resolving base datatypes from User Defined Datatypes.

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3> 4> 5> SELECT t1.name, t2.name 6> FROM systypes t1 JOIN systypes t2 7> ON t1.type = t2.type 8> WHERE t1.usertype >= 100 9> AND t2.usertype < 100 10> AND t2.usertype NOT IN (18,80) 11> GO name name

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id sql_variant id varchar id nvarchar

(3 rows affected) 1></source>