c# - SQL Server -> .Net int conversion -


i had line of code in winforms app (target platform x86) made contained this...

if (dtmax.rows[0][0] != system.dbnull.value)        iprevmax = (int64)(dtmax.rows[0][0]);

i know dtmax.rows[0][0] max of column in given table in sql server. datatype of column int.

now - line of code @ point threw exception. don't know exception on holiday , nobody took note!! angry face.

however line changed to....

if (dtmax.rows[0][0] != system.dbnull.value)        iprevmax = convert.toint64(dtmax.rows[0][0]);

...and works.

i understand few things...

  • .net equivalent of sqlserver int int32 - should have been unboxing that.

  • convert "safer" unboxing

but don't understand why line of code work , @ point fail unbox? possible reasons - in spite of annoyingly not knowing actual exception...


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