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SQlite file locking - again help needed [message #33466]

Wed, 10 August 2011 10:01

papascalientes
Messages: 5
Registered: February 2011

Promising Member

Could someone perhaps give me an example of how to handle file locking situations when writing to an SQlite database in an application that is running on a network? I have to use SQlite databases and everything I tried (thank you Mirek for your earlier help) didn't work the way I wanted.

The basic code I use without handling file locking looks like this example for a write operation on an already existing sqlite database Z.db3 with a table named ZTABLE:

******* begin code example ********************************

Sqlite3Session z_sql3;		
if(!z_sql3.Open(z.db3))
   throw Exc("Can't create or open database file: Z.db3");

   
Sql sqlz(z_sql3); 
z_sql3.Begin();   

cInsertstring="INSERT INTO ZTABLE VALUES("firtst nametest, last nametest")";      // using testvariables 

sqlz.ClearError();
sqlz.Execute(cInsertstring);

z_sql3.Commit();
z_sql3.Close();

*************** end of example **********************************

How and where can I check, whether the database is locked (SQL_BUSY error) and if it is locked, retry to write 5 times?

And (where) do I have to use a ROLLBACK? I am not quite sure in which cases a rollback is done automatically by sqlite.

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