Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
SQL Join or Where
Message
De
03/03/2001 08:05:02
Edward See
Magicalogic Consultancy System
Quezon, Philippines
 
 
À
02/03/2001 12:03:52
Cindy Winegarden
Duke University Medical Center
Durham, Caroline du Nord, États-Unis
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00481412
Message ID:
00481650
Vues:
9
>Edward
>
>WHERE is the same as INNER JOIN. You have to use LEFT JOIN to get parent records which have no matching children. In SQL installaations which don't support the JOIN statement you can sinmulate this with a UNION of the records that are "NOT IN."
>
>You didn't say whether you're using VFP only or using the SQL language to access some other ODBC compliant database. The best SQL book is Joe Celko's SQL for Smarties: Advanced SQL Programming, Second Edition. He's also written a book called something like "SQL Puzzles and Answers."
>
>With VFP only you can also use SELECT LOOKUP(...) AS MyLookedUpField ... without referencing the lookup table in the FROM clause.
>
>
>>Please enlighten anyone
>>
>>which do you use :
>>
>>Select * ;
>> from parent,child ;
>> where parent.key=child.key ;
>> into cursor temp
>>
>>or
>>
>>Select * ;
>> from parent ;
>> join child on parent.key=child.key ;
>> into cursor temp
>>
>>Can anyone recommend a very good book on the use of SQL-SELECT where there are very good or much better excellent examples on the use of nested select statements that span several child tables and span lookup tables in one SQL statement ???

Thanks a lot. I'll look for the book here in the Philippines if they have it.
By the way, I'll be using it in VFP and recently on Oracle.
Use things, not people. Love people, not things
Précédent
Répondre
Fil
Voir

Click here to load this message in the networking platform