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Showing posts from April, 2014

Hey, I rewrote UNION by way of UNPIVOT

Yesterday a team mate of mine asked me to review a piece of SQL script that looked like a good candidate for UNPIVOT. Below is the amended version of that code (I obfuscated the data and added a simple data initialization using the WITH clause): ;with u as ( -- data setup select * from ( values(1, 1, 1, 1), (2, 1, 1, 0), (3, 1, 0, 0), (4, 0, 0, 0) ) t(UserID, HasDbSkills, HasBackendSkills, HasFrontEndSkills) ) select * from ( select UserID, 0 as SkillType, 1 as DevelopmentSkill from u where HasDbSkills = 1 union select UserID, 1 as SkillType, 1 as DevelopmentSkill from u where HasBackendSkills = 1 union select UserID, 2 as SkillType, 1 as DevelopmentSkill from u where HasFrontEndSkills = 1 ) t(UserID, SkillType, DevelopmentSkill) order by UserID, SkillType Indeed, after a quick analysis, this script turned out to be ripe for UNPIVOT:

T-SQL: COALESCE returns int for integer operations

DECLARE @can_import BIT PRINT CAST (SQL_VARIANT_PROPERTY( COALESCE (@can_import, 0), 'BaseType') AS VARCHAR(20)) Result: int