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multiple connections to a sqlite database
- Thread starter Peter
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The database containes several tables, linked by other tables in the same database.
for example:
table 1 containes films + details, primary key is the filmnumber
table 2 containes filmnumber, personalnumber, functionnumber
table 3 containes data about a person, primary key is personalnumber
Several persons can have the same function with a film.
Connection 1 would be for selecting all personalnumbers with a function in a certain film
connection 2 would be for selecting the data for each person in the results of connection 1.
I had thought this would be the easiest way to get the results i want, instead of storing the results of connection 1 in a temporary variable.
Peter
for example:
table 1 containes films + details, primary key is the filmnumber
table 2 containes filmnumber, personalnumber, functionnumber
table 3 containes data about a person, primary key is personalnumber
Several persons can have the same function with a film.
Connection 1 would be for selecting all personalnumbers with a function in a certain film
connection 2 would be for selecting the data for each person in the results of connection 1.
I had thought this would be the easiest way to get the results i want, instead of storing the results of connection 1 in a temporary variable.
Peter
Two connections will not help here.
You could do it with one command.
Something like:
SELECT * FROM tabl1, table2, table3 WHERE table1.filmnumber = table2.filmnumber AND table2.personalnumber = table3.personalnumber
Search the web for SQL join for more information.
You could do it with one command.
Something like:
SELECT * FROM tabl1, table2, table3 WHERE table1.filmnumber = table2.filmnumber AND table2.personalnumber = table3.personalnumber
Search the web for SQL join for more information.
I know it can be done in one query, in fact it is the easiest (programming)way. The downside of this is a much worse performance.
I haven't tried this with b4ppc (obviously), but i've had some experience with a comparable situation in VB6 on the PC. When i did a single query the results took about 14 seconds, while two queries together took a fraction of a second. Which is why i prefer to do it likewise on the PPC, which requieres two connections.
Peter
I haven't tried this with b4ppc (obviously), but i've had some experience with a comparable situation in VB6 on the PC. When i did a single query the results took about 14 seconds, while two queries together took a fraction of a second. Which is why i prefer to do it likewise on the PPC, which requieres two connections.
Peter