Database crash issue at the time of retrieving data

Question

enter image description here This is the Database field values.

Below is the code which I am applying to fetch data from sqlite database

-(void)readDataFromRestaurantTable
{
    [self openDataBase];

    const char *dbpath = [databasePath UTF8String];

    if (sqlite3_open(dbpath, & database) == SQLITE_OK)
    {
        sqlite3_stmt  *statement = NULL;

        NSString *querySQL = [NSString stringWithFormat: @"SELECT * FROM RestaurantDB"];
        const char *query_stmt = [querySQL UTF8String];

        if (sqlite3_prepare_v2(database, query_stmt, -1, &statement, NULL) == SQLITE_OK) {

            while (sqlite3_step(statement) == SQLITE_ROW)
            {
                strRestaurantName = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
                strRestaurantAddress = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
                strRestaurantPhone = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 3)];
                strRestaurantLatitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 4)];
                strRestaurantLongitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];

                NSLog(@"strRestaurantName :--> %@",strRestaurantName);
            }
        }
        sqlite3_finalize(statement);
    }
    sqlite3_close(database);
}

In the previous block of code application is not going inside the

if (sqlite3_prepare_v2(database, query_stmt, -1, &statement, NULL) == SQLITE_OK)
{

}

Here it is getting statement = 0x00000000 & I think because of this reason only it is not going into the if block.

Error at the time of crash

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSPlaceholderString initWithUTF8String:]: NULL cString'
First throw call stack:
(0x18dc012 0x12a1e7e 0x18dbdeb 0xcbdce6 0x78e4 0x7bdf 0x2ca817 0x2ca882 0x2ebed9 0x2ebd14 0x2ea1ea 0x2ea06c 0x2ebc57 0x12b5705 0x1ec920 0x1ec8b8 0x40f0b4 0x12b5705 0x1ec920 0x1ec8b8 0x2ad671 0x2adbcf 0x2ad6a6 0x412bb9 0x12b5705 0x1ec920 0x1ec8b8 0x2ad671 0x2adbcf 0x2acd38 0x21c33f 0x21c552 0x1fa3aa 0x1ebcf8 0x1da5df9 0x185ff3f 0x185f96f 0x1882734 0x1881f44 0x1881e1b 0x1da47e3 0x1da4668 0x1e965c 0x2712 0x2645 0x1)
libc++abi.dylib: terminate called throwing an exception

Please guide me where is the actual problem lies.

check this:-http://stackoverflow.com/questions/8317732/sqlite3-inserting-a-null-value — Nitin Gohel, Jan 31 '13 at 05:42
I had same issues in iOS 6.1; try to test in 5.0/5.1.. to see if you have the same behavior.. — TonyMkenu, Jan 31 '13 at 10:32

score 8 · Accepted Answer · answered Jan 31 '13 at 05:23

8

This is being caused by trying to create a NSString object with a NULL string. It is on one of these lines:

[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, ...)];

So, before you create a NSString with the results of the sql statement you need to check for NULL like this:

char *tmp = sqlite3_column_text(statement, 1);
if (tmp == NULL)
    strRestaurantName = nil;
else
    strRestaurantName = [[NSString alloc] initWithUTF8String:tmp];

answered Jan 31 '13 at 05:23

lnafziger

25,760
8
60
101

Each time it is going into the first NULL condition. – Jignesh Fadadu Jan 31 '13 at 05:33
Are all of them NULL, or only the first string? – lnafziger Jan 31 '13 at 05:44

Nitin Gohel · Answer 2 · 2013-01-31T05:44:25.183

you have to check first data is NULL or not befor Bind it like bellow:-

const char* date = (const char*)sqlite3_column_text(statement, 3);
NSString *enddate = date == NULL ? nil : [[NSString alloc] initWithUTF8String:date];

Impliment it in your method bellow:

-(void)readDataFromRestaurantTable {

    [self openDataBase];
    if (sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) 
     {

        const char *sql = "SELECT * FROM RestaurantDB";
        sqlite3_stmt *selectstmt;
        if(sqlite3_prepare_v2(database, sql, -1, &selectstmt, NULL) == SQLITE_OK) 
            {

                while(sqlite3_step(selectstmt) == SQLITE_ROW) 
                {

                strRestaurantName = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
                strRestaurantAddress = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
                strRestaurantPhone = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 3)];
                strRestaurantLatitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 4)];
                strRestaurantLongitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];

               }
        }
    }
    else
        sqlite3_close(database); //Even though the open call failed, close the database connection to release all the memory.
}

might be its helps you :)

Thnaks @Nitin...This is also having the same problem, as I was facing previously. — Jignesh Fadadu, Jan 31 '13 at 05:37
check my updated Answer:- and Also refur this link:http://stackoverflow.com/questions/3820086/iphone-sqlite3-how-do-detect-a-null-date-getting-error-when-assigning-to-a-ns — Nitin Gohel, Jan 31 '13 at 05:45

score 1 · Answer 3 · answered Jan 31 '13 at 06:17

1

Write sqlite3_finalize(statement); inside the if condition:

 if (sqlite3_prepare_v2(database, query_stmt, -1, &statement, NULL) == SQLITE_OK)
 {

        while (sqlite3_step(statement) == SQLITE_ROW)
        {
            strRestaurantName = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
            strRestaurantAddress = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
            strRestaurantPhone = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 3)];
            strRestaurantLatitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 4)];
            strRestaurantLongitude = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];

            NSLog(@"strRestaurantName :--> %@",strRestaurantName);
        }
     sqlite3_finalize(statement);
 }

answered Jan 31 '13 at 06:17

Midhun MP

103,496
31
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200

this is not going inside the if condition because of null "statement". – Jignesh Fadadu Jan 31 '13 at 06:30
@JohnPatel: it is not going because there is issue in your query or database. – Midhun MP Jan 31 '13 at 06:32
That issue only I am not getting. – Jignesh Fadadu Jan 31 '13 at 06:34
@JohnPatel: first check that the db path is correct, then check that the table exist in database. Then change this `sqlite3_stmt *statement = NULL;` to `sqlite3_stmt *statement;` – Midhun MP Jan 31 '13 at 06:37
Thanks All but this issue was because of nill Database name. – Jignesh Fadadu Jan 31 '13 at 13:42

score 1 · Answer 4 · edited Jun 02 '15 at 13:17

I came through the same Error.
Instead of checking NULL or blank values, we can modify the SQL query to return NOT NULL/BLANK values.

In the below Query, the restaurant name is validated for blank/null values @ the database level.

NOTE: Excuse the Syntax error if any..Have considered only 1 column.

Ex:

const char *sql = "SELECT * FROM RestaurantDB WHERE <restuarant_Name column> != '' AND <restuarant_Name column> IS NOT NULL";
        sqlite3_stmt *selectstmt;
        if(sqlite3_prepare_v2(database, sql, -1, &selectstmt, NULL) == SQLITE_OK) 
            {
             while(sqlite3_step(selectstmt) == SQLITE_ROW) 
                {
                  strRestaurantName = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
                }
            }

score 1 · Answer 5 · answered May 30 '16 at 10:52

in my case i get the same error when I skipped the first column 'regno' in db table. But when i add the first column header'regno' and declared as NSString inside the method cleared the error.

`-(NSArray*)loadData {

     const char *dbpath = [databasePath UTF8String];

    if (sqlite3_open(dbpath, &database) == SQLITE_OK) {
        NSString *querySQL = [NSString stringWithFormat:@"select regno, firstname, middlename, lastname, gender, dob, bloodgroup, mobileno, emailid from personalDetails"];

        NSMutableArray *resultArray = [[NSMutableArray alloc]init];
        const char *query_stmt = [querySQL UTF8String];

        if (sqlite3_prepare_v2(database, query_stmt, -1, &statement, NULL) == SQLITE_OK )
        {

            if (sqlite3_step(statement) == SQLITE_ROW) {

                ***NSString *regNo = [[NSString alloc] initWithUTF8String:
                                       (const char *) sqlite3_column_text(statement, 0)];
                [resultArray addObject:regNo];***


                NSString *firstname = [[NSString alloc] initWithUTF8String:
                                       (const char *) sqlite3_column_text(statement, 1)];
                [resultArray addObject:firstname];
                NSString *middlename = [[NSString alloc] initWithUTF8String:
                                        (const char *) sqlite3_column_text(statement, 2)];
                [resultArray addObject:middlename];
                NSString *lastname = [[NSString alloc]initWithUTF8String:
                                      (const char *) sqlite3_column_text(statement, 3)];
                [resultArray addObject:lastname];
                NSString *gender = [[NSString alloc]initWithUTF8String:
                                    (const char *) sqlite3_column_text(statement, 4)];
                [resultArray addObject:gender];
                NSString *dob = [[NSString alloc]initWithUTF8String:
                                 (const char *) sqlite3_column_text(statement, 5)];
                [resultArray addObject:dob];
                NSString *bloodgroup = [[NSString alloc]initWithUTF8String:
                                        (const char *) sqlite3_column_text(statement, 6)];
                [resultArray addObject:bloodgroup];
                NSString *mobileno = [[NSString alloc]initWithUTF8String:
                                      (const char *) sqlite3_column_text(statement, 7)];
                [resultArray addObject:mobileno];
                NSString *emailid = [[NSString alloc]initWithUTF8String:
                                     (const char *) sqlite3_column_text(statement, 8)];
                [resultArray addObject:emailid];


                return resultArray;
            }
            else{
                NSLog(@"Not found");
                return nil;
            }
            sqlite3_reset(statement);




        }
    }


    return nil;
}'

Database crash issue at the time of retrieving data

5 Answers5

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