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GeneralRe: Please recommend on connection to Ms Acess Database Pin
EdbertP29-Jul-04 16:52
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GeneralUser access to SQL Server database Pin
Colin Angus Mackay29-Jul-04 6:35
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GeneralRe: User access to SQL Server database Pin
Grimolfr29-Jul-04 7:56
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GeneralRe: User access to SQL Server database Pin
Colin Angus Mackay29-Jul-04 22:37
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QuestionODBC API's code examples? Pin
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Generalxml to excel Help! Pin
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GeneralCreate System Database form C# using ADOX Pin
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GeneralNeed help!!! Pin
yanh10027-Jul-04 14:12
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QuestionCan I call OLEDB and ADO from the same app? Pin
CherezZaboro27-Jul-04 8:34
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GeneralADO Connection Failure...HELP!!!!! Pin
girl_lash26-Jul-04 21:27
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GeneralRe: ADO Connection Failure...HELP!!!!! Pin
Bill Dean27-Jul-04 4:45
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GeneralRe: ADO Connection Failure...HELP!!!!! Pin
girl_lash27-Jul-04 14:22
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GeneralRe: ADO Connection Failure...HELP!!!!! Pin
Bill Dean28-Jul-04 9:49
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GeneralUsing MDB database with OLEDB/ATL/MFC (from SQL Server) Pin
Gian26-Jul-04 2:15
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GeneralWindows-only authentication not working Pin
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GeneralRe: Windows-only authentication not working Pin
Mike Dimmick26-Jul-04 5:29
Mike Dimmick26-Jul-04 5:29 
GeneralCurious about a query Pin
brdavid25-Jul-04 15:12
brdavid25-Jul-04 15:12 
GeneralRe: Curious about a query Pin
Grimolfr26-Jul-04 4:26
Grimolfr26-Jul-04 4:26 
GeneralRe: Curious about a query Pin
brdavid26-Jul-04 6:04
brdavid26-Jul-04 6:04 
GeneralRe: Curious about a query Pin
Michael Potter26-Jul-04 10:36
Michael Potter26-Jul-04 10:36 
GeneralRe: Curious about a query Pin
Grimolfr26-Jul-04 11:28
Grimolfr26-Jul-04 11:28 
Like Michael said. The LIKE keyword is specifically used for pattern matching, and even if you don't use a pattern, the query builder will still probably build the query using the pattern matching algorithm, which is always going to be less efficient than a simple equality algorithm. Depending on the data you're matching, the difference could be inconsequential, or it could be dramatic.

Plus, if you have the field indexed, the equality comparison (or >, <, >=, <=, etc) will use the index much more efficiently. The LIKE operator will do a full index scan, to look for all fields that might match the pattern. The equality operator can use the index as it's intended, by starting with only the rows where that field begins with 'S'. Some database engines may automatically do this with LIKE statements that don't begin with a wildcard. Others may not.

AND, the real reason I brought it up. The IN keyword replaces multiple equality checks. I.e. field IN ('Val1', 'Val2') is translated by the query builder into (field = 'Val1' OR field = 'Val2'). Note that the only difference in this and your original query is the parentheses, which can make all the difference in the world if used properly (or not, as the case may be.)


Grim
(aka Toby)
MCDBA, MCSD, MCP+SB


SELECT * FROM user WHERE clue IS NOT NULL
GO
(0 row(s) affected)

GeneralHOW: format date field in sql Pin
JabraJabra25-Jul-04 13:16
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GeneralRe: HOW: format date field in sql Pin
darkbyte29-Jul-04 1:37
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GeneralData type Pin
Peter Mayhew25-Jul-04 4:42
Peter Mayhew25-Jul-04 4:42 
GeneralRe: Data type Pin
Peter Mayhew27-Jul-04 9:24
Peter Mayhew27-Jul-04 9:24 

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