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SQL

SQL. NULL values. SQL: NULLs. Select A 1 , A 2 ,…, A n From R 1 , R 2 , …, R m Where condition. Demo: simple college admissions database College ( cName , state , enrollment ) Student ( sID , sName , GPA , sizeHS ) Apply ( sID , cName , major , decision ). NULL values:

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SQL

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  1. SQL NULL values

  2. SQL: NULLs Select A1,A2,…,An From R1,R2, …,Rm Where condition Demo: simple college admissions database College(cName,state,enrollment) Student(sID,sName,GPA,sizeHS) Apply(sID,cName,major,decision) NULL values: undefined or unknown

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