How to delete a row in a sqlite database table?
I am using fmdb for managing my database. I could not find any example for deleting a row from a table in fmdb. I tried
NSString *sqlStat=@"DELETE from tableName WHERE id=3";
FMResultSet *rs = [database executeQuery:sqlStat];
but its not working because when I checked the total number of entries in 开发者_StackOverflowtable, I am getting the same number as before executing the above statement. So, what is a proper way to delete a row from a table using fmdb?
FMDB can be a little finicky if you dont pass in the object as an NSNumber. This is the supported, and safe way of formatting queries.
[db executeUpdate:@"DELETE FROM theTable WHERE id = ?", [NSNumber numberWithInt:myObject.id]];
You should replace:
... [database executeQuery:sqlStat] ...
with:
... [database executeUpdate:sqlStat];
Also, try adding:
[database beginTransaction];
before your CRUD block, and:
[database commit];
after executing an update/delete/insert operation.
;)
i also ran into the same symptom. and my problem was i didnt call (and caused "out of memory" error)
[db open];
be sure to do this to debug your fmdb issues db.traceExecution=YES; db.logsErrors=YES;
you need to ensure all the processes
NSString *query = @"delete from places where published = 1";
const char *sqlStatement = [query UTF8String];
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {
// Loop through the results and add them to the feeds array
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
// Read the data from the result row
NSLog(@"result is here");
}
// Release the compiled statement from memory
sqlite3_finalize(compiledStatement);
}
int numberOfEffectedRow = sqlite3_changes(database);
return numberOfEffectedRow; // get number of effected rows
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