cocoa - sql语句sqlite3_column_text有什么问题？

Question

if(sqlite3_open([databasePath UTF8String], & database) == SQLITE_OK) {
    NSLog(@"DB OPENED");
    // Setup the SQL Statement and compile it for faster access
    const char *sqlStatement ="select name from Medicine";

    sqlite3_stmt *compiledStatement;

    int result = sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, nil); 
    NSLog(@"RESULT %d", result);

    if(result == SQLITE_OK) {
        NSLog(@"RESULT IS 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(@"WHILE IS OK");

            **araci = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];**

            NSLog(@"Data read");


            NSLog(@"wow: %",araci);


        }//while 
    }//if sqlite_prepare v2
    // Release the compiled statement from memory
    sqlite3_finalize(compiledStatement);
    NSLog(@"compiled stmnt finalized..");
}
sqlite3_close(database);
NSLog(@"MA_DB CLOSED");

问题

1 ) 一切正常，直到出现粗体代码。当我运行该应用程序时，抛出下面的异常。我的数据库中有一张表和一行，id(整数)、name(varchar)、desc(varchar)(我使用 SQLite Manager 创建了表)。

2-) SQLite Manager 中的文本类型是什么？那是 NSString 吗？另外，如何将字符串值(在表中)放入 NSMutableArray 中？ (我真的很难转换。)

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** +[NSString stringWithUTF8String:]: NULL cString'

Answer 1

要处理数据库返回的null，可以使用下面的代码来处理

char *localityChars =  (char *)sqlite3_column_text(init_statement, 12);

if (localityChars ==null)
     self.Locality = nil;
else
     self.Locality = [NSString stringWithUTF8String: localityChars];