E-Mail Validator

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E-Mail Validator

Sean Smith

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Points: 5977
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November 20, 2009 at 1:55 am

#214037

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Dennis Wagner-347763 SSC Eights! Points: 945 More actions · Answer 1

Very nice.

I would make a couple of suggestions though. To avoid the loop looking at each individual character, use regular expressions to look for invalid characters:

IF (

@vParameter_Length = 0

OR CHARINDEX ('@', @vParameter) < 2

OR CHARINDEX ('.', @vParameter) < 2

OR CHARINDEX ('.@', @vParameter) <> 0

OR CHARINDEX ('..', @vParameter) <> 0

OR CHARINDEX ('.', REVERSE (@vParameter)) < 3

OR CHARINDEX ('.', @vParameter, CHARINDEX ('@',@vParameter)) = 0

OR RIGHT (@vParameter,1) = '@'

OR @vParameter LIKE '%@%@%'

OR @vParameter LIKE '%[!-*]%'

OR @vParameter LIKE '%,%'

OR @vParameter LIKE '%/%'

OR @vParameter LIKE '%[:-?]%'

OR @vParameter LIKE '%[[-^]%'

OR @vParameter LIKE '%`%'

OR @vParameter LIKE '%[{-~]%'

)

Then if you are going to do it on an entire table, you can avoid the function altogether which would probably bring your SQL Server to its knees to have a function in the where clause of a select against a million row table. This query ran against an 800,000+ row table in about 4 seconds.

cfrestrepo SSC Enthusiast Points: 144 More actions · Answer 2

I found this code in Internet some time ago.

I modify to Sqlserver

create FUNCTION IsValidEmail

(@Email varchar(100))

RETURNS bit

AS

BEGIN

Declare @Long Int,

@Pos Int,

@Bueno Bit,

@Ext varchar(1000),

@Letras varchar(100),

@I Int

Set @Letras = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ@.-_0123456789'

Set @Email = rtrim(ltrim(@Email))

Set @Long = Len(@Email)

Set @Pos = CharIndex('@',@Email)

Set @Bueno = 0

If not (@Long < 6 -- Muy corto (very short)

Or @Pos = 0 -- No hay arrobas (no @s-2)

Or CharIndex('@',@Email,CharIndex('@',@Email)+1) > 0 -- dos o mas arrobas (more than 1 @)

Or CharIndex(left(@Email,1),'@.-_') > 0 -- No empieza por '@.-_'

Or CharIndex(right(@Email,1),'@.-_') > 0 -- No termina en '@.-_'

Or CharIndex('@.',@Email) > 0

or CharIndex('..',@Email) > 0

or CharIndex('.@',@Email) > 0) -- @. ó ..

Begin

Set @Ext = '.COM.EDU.GOV.NET.BIZ.ORG.TV.INFO'

+ '.AF.AL.DZ.As.AD.AO.AI.AQ.AG.AP.AR.AM.AW.AU.AT.AZ.BS.BH.BD.BB.BY'

+ '.BE.BZ.BJ.BM.BT.BO.BA.BW.BV.BR.IO.BN.BG.BF.MM.BI.KH.CM.CA.CV.KY'

+ '.CF.TD.CL.CN.CX.CC.CO.KM.CG.CD.CK.CR.CI.HR.CU.CY.CZ.DK.DJ.DM.DO'

+ '.TP.EC.EG.SV.GQ.ER.EE.ET.FK.FO.FJ.FI.CS.SU.FR.FX.GF.PF.TF.GA.GM.GE.DE'

+ '.GH.GI.GB.GR.GL.GD.GP.GU.GT.GN.GW.GY.HT.HM.HN.HK.HU.IS.IN.ID.IR.IQ'

+ '.IE.IL.IT.JM.JP.JO.KZ.KE.KI.KW.KG.LA.LV.LB.LS.LR.LY.LI.LT.LU.MO.MK.MG'

+ '.MW.MY.MV.ML.MT.MH.MQ.MR.MU.YT.MX.FM.MD.MC.MN.MS.MA.MZ.NA'

+ '.NR.NP.NL.AN.NT.NC.NZ.NI.NE.NG.NU.NF.KP.MP.NO.OM.PK.PW.PA.PG.PY'

+ '.PE.PH.PN.PL.PT.PR.QA.RE.RO.RU.RW.GS.SH.KN.LC.PM.ST.VC.SM.SA.SN.SC'

+ '.SL.SG.SK.SI.SB.SO.ZA.KR.ES.LK.SD.SR.SJ.SZ.SE.CH.SY.TJ.TW.TZ.TH.TG.TK'

+ '.TO.TT.TN.TR.TM.TC.TV.UG.UA.AE.UK.US.UY.UM.UZ.VU.VA.VE.VN.VG.VI'

+ '.WF.WS.EH.YE.YU.ZR.ZM.ZW'

Set @Pos = @Long + 1 - CharIndex('.',Reverse(@Email)) -- localiza el último punto (locate last period)

If CharIndex(substring(@Email, @Pos,60), @Ext) > 0 -- Chequea terminación válida

Begin

Set @I = 1

While @I <= @Long

Begin

If CharIndex(Substring(@Email,@I,1),@Letras) = 0 -- Letra o caracter inválido (invalid char)

Break

Set @I = @I + 1

End

If @Long < @I

Set @Bueno = 1

End

Return @Bueno

Sean Smith SSCertifiable Points: 5977 More actions · Answer 3

Very nice! Thanks for all of the helpful tips and tricks. 🙂

JediSQL SSCrazy Points: 2118 More actions · Answer 4

Dennis,

I like your pattern matching approach. However, I was concerned about the 128 extended characters, so I suggest the last condition be modified to changed the ~ to a ÿ, like this:

OR @vParameter LIKE '%[{-ÿ]%'

Sincerely,
Daniel