Change default number of attached databases

[Columbo]

It seems that SQLite allows 125 databases to be attached however, the default is 10. How do you change this default value to something slightly higher?

Thanks

[percy_b]

It seems that SQLite allows 125 databases to be attached however, the default is 10. How do you change this default value to something slightly higher?

Thanks

Hi,

I may be wrong, but I believe that is a compile-time limitation. However, you can lower the number of connected databases by calling "sqlite3_limit".

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[Columbo]

I want to increase the number higher than 10. I'm not sure how to do this or what the syntax would be if it is a compile-time limitation?

[percy_b]

I want to increase the number higher than 10. I'm not sure how to do this or what the syntax would be if it is a compile-time limitation?

You will need to re-compile the Sqlite source code and increase the value for the SQLITE_MAX_ATTACHED manifest constant. By default, it is set to 10.

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[Columbo]

You will need to re-compile the Sqlite source code and increase the value for the SQLITE_MAX_ATTACHED manifest constant. By default, it is set to 10.

Where do I find the SQLite source and what compiler is it compiled with? I thought that SQLite was installed with PB?

[percy_b]

You will need to re-compile the Sqlite source code and increase the value for the SQLITE_MAX_ATTACHED manifest constant. By default, it is set to 10.

Where do I find the SQLite source and what compiler is it compiled with? I thought that SQLite was installed with PB?

SQLite is built into PureBasic. However, if you wish to customize SQLite, you will need to modify the canonical source code. You will also need a C compiler. You can get more information about that here:

https://SQLite.org/getthecode.html
https://SQLite.org/howtocompile.html

If you want to use the above approach, you will most likely have to use SQLite as a dll.

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[Columbo]

Thank you for your help. I don't know why they allow 125 attachments but set it to default to 10 and then make it so difficult to change the default.

It would be great if you could just use something like this in Purebasic:

Code: Select all

UseSQLiteDatabase()
Set SQLITE_MAX_ATTACHED = 18

Oh well, I guess I'll have to find another way to handle this problem.

Thanks again.

[kpeters58]

Are you sure this is a real world problem?

Why would you want to attach to that many databases simultaneously? Remember, you can always detach and re-attach...

[Columbo]

Why would you want to attach to that many databases simultaneously? Remember, you can always detach and re-attach...

It is for a recipe program which has a categories database with subcategories attached. I guess detaching and re-attaching is an option but it seemed much easier and less coding to be able to attach all of the subcategories.

Thanks for the suggestion. I'll play with it a bit.

[Fangbeast]

Why would you want to attach to that many databases simultaneously? Remember, you can always detach and re-attach...

It is for a recipe program which has a categories database with subcategories attached. I guess detaching and re-attaching is an option but it seemed much easier and less coding to be able to attach all of the subcategories.

Thanks for the suggestion. I'll play with it a bit.

I might have missed your point but why do the categories need to be in another database? I wrote a recipe manager years ago with a lot of help (as usual) and the categories are in the same database but a separate table in the same database. They don't need another database to function and none of the commercial programs do it that way.

I analysed Living Cookbook, Paprika and Mastercook's databases and their their related tables are in the one database and joined by queries.

Just wondering.

[kpeters58]

I am with Fangbeast on this one:

These should be different tables in the same database...

[skywalk]

I have use cases where attached db's approach 10 or 12. It should default to a higher count. But, we can now recompile with all our custom settings and choose the resulting dll in usesqlitedatabase().