CODEWITHSUNDEEP
iosobjective-csqlite
Gobinath Ed
Gobinath Ed

Reputation: 229

How to find out the SQLITE query result is NULL?

I've used the following method in my app,

-(int) getMax:(NSString *)subItemName second :(int) tableID
{
    int count1=0;
    sqlite3_stmt *statement;
    NSString *query = [NSString stringWithFormat:@"Select MAX(NoOfItems) from billTable where SubItemName='%@' AND TableID='%d'",subItemName,tableID];
    if (sqlite3_prepare_v2(_database, [query UTF8String], -1, &statement, nil)== SQLITE_OK) {
     while (sqlite3_step(statement) == SQLITE_ROW) {
            count1 = [[NSString stringWithUTF8String:(char *) sqlite3_column_text(statement, 0)]intValue];
        }

        sqlite3_step (statement);
    }
    return count1;
}

As you can see that the my query will return the no of rows (an integer), suppose if my query returns a NULL value(if there is no such exists for the where clause condition in my database it returns NULL value. How to check it returns NULL after the query has been executed?

Upvotes: 0

Views: 1169

Answers (1)

CL.
CL.

Reputation: 180030

You can call sqlite3_column_type() to find out what type a column value has:

if (sqlite3_prepare_v2(_database, [query UTF8String], -1, &statement, nil)== SQLITE_OK) {
    if (sqlite3_step(statement) == SQLITE_ROW) {
        if (sqlite3_column_type(statement, 0) == SQLITE_NULL)
            count1 = -1; // or whatever
        else
            count1 = sqlite3_column_int(statement, 0);
    }
    sqlite3_finalize(statement);
}

Upvotes: 1

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