sqlite select method implement issue for iOS - ios

Question

I am trying to retrieve some data from my sqlite table base on a date, but I am getting EXC_BAD_ACCESS(code=EXC_1386_GPFLT) error. Here is my method to fetch data-
-(NSMutableArray*)fetchDataFromTable:(NSString*)tableName whenDate:(NSString*)activeDate{
NSMutableArray *resultArray=[[NSMutableArray alloc]init];
NSString *query = [NSString stringWithFormat:#"select * from %# where ActiveDate = \"%#\"", tableName, activeDate];
if ([self canOpenDatabase]) { //checks if database can be openned
sqlite3_stmt *statement=nil;
if(sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, NULL) == SQLITE_OK) {
while (sqlite3_step(statement) == SQLITE_ROW){
NSMutableArray *fetchedResults=[[NSMutableArray alloc]init];
int numberOfColumns = sqlite3_column_count(statement);
for (int i=0; i< numberOfColumns; i++){
char *dataAsChars = (char *)sqlite3_column_text(statement, i);
if (dataAsChars != NULL) {
NSString *dataString = [[NSString alloc] initWithUTF8String:dataAsChars];
[fetchedResults addObject:dataString];
}
}
[resultArray addObject:fetchedResults];
sqlite3_finalize(statement);
sqlite3_close(database);
}
}
else{
NSLog(#"Data can not be retrived");
}
return resultArray;
}
else{
return resultArray;
}
}
I also trying printing the query. It shows
select * from Time_table where ActiveDate = "2016-01-01"
Please Help me out.

Answer 1

There are several issues.
Pair the call to sqlite3_close with the success of opening the database.
Pair the call to sqlite_finalize with the success of preparing the statement.
Don't close the database or finalize the statement inside the loop.
Don't build queries using stringWithFormat. Properly bind values into the prepared statement.

Answer 2

The issue was very obvious yet very intuitive. I am glad that I faced this issue. At least I won't do it again. So, here is the simple fix and the reason behind it-
In case of database object fetching, EXC_BAD_ACCESS normally happens when -
An object is not initialised or
An object is already released untimely
So, in case, I were never to use the prepared statement or completely done working with the statement, I should use sqlite_finalize. In may method, I used the statement after I finalised the statement.
So the easy fix was to finalise after the while statement-
-(NSMutableArray*)fetchDataFromTable:(NSString*)tableName whenDate:(NSString*)activeDate{
NSMutableArray *resultArray=[[NSMutableArray alloc]init];
NSString *query = [NSString stringWithFormat:#"select * from %# where ActiveDate = \"%#\"", tableName, activeDate];
if ([self canOpenDatabase]) {
sqlite3_stmt *statement=nil;
if(sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, NULL) == SQLITE_OK) {
while (sqlite3_step(statement) == SQLITE_ROW){
NSMutableArray *fetchedResults=[[NSMutableArray alloc]init];
int numberOfColumns = sqlite3_column_count(statement);
for (int i=0; i< numberOfColumns; i++){
char *dataAsChars = (char *)sqlite3_column_text(statement, i);
if (dataAsChars != NULL) {
NSString *dataString = [[NSString alloc] initWithUTF8String:dataAsChars];
[fetchedResults addObject:dataString];
}
}
[resultArray addObject: fetchedResults];
}
sqlite3_finalize(statement);
}
else{
NSLog(#"Data can not be retrived");
}
sqlite3_close(database);
return resultArray;
}
else{
return resultArray;
}
}