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sqlite3_column_text returns NULL when there is data in the database

My database is defined as the following

CREATE TABLE [problems] (
[p_id] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, 
[problem_name] VARCHAR(255) NOT NULL, 
[mixed_t1] INT NOT NULL, 
[mixed_t2] INT NOT NULL, 
[mixed_flair] INT, 
[mixed_gre] INT, 
[mixed_diffusion] INT, 
[mixed_adc] INT, 
[fat_sat_post_t1] INT)

In my code, I'm trying to run an SQL query that looks like

SELECT problem_name from problems W开发者_StackOverflow中文版HERE mixed_t1=0

Then in code, I'm trying to assign the problem_name to a NSString and then add the NSString to an NUSMutableArray

if(sqlite3_step(statement) == SQLITE_ROW)
{

    NSString *problemName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 1)];

    [dataSet addObject:problemName];

    [problemName release];
}

The problem is that I'm crashing at NSString *problemName

I get the following crash message

Current language:  auto; currently objective-c
2011-02-08 08:54:29.035 RadAppz[1332:207] *** Terminating app due to uncaught exception    'NSInvalidArgumentException', reason: '*** +[NSString stringWithUTF8String:]: NULL cString'

* Call stack at first throw:

I know I'm getting data because executing the RAW SQL in Terminal returns 2 rows. Can someone please tell me why the data is being returned as NULL?


Your problem, I believe, is that you are checking for the second column, not the first. Note that the definition for sqlite3_column_text states that the leftmost column is column 0.

http://www.sqlite.org/capi3ref.html#sqlite3_column_blob

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