Question

我有一个项目，在其中我创建了sqlite DB。现在我希望从Sqlite读取数据并存储在NSMutableArray中并显示在UITableView这是我的代码，但是当我逐步编译该程序时。这个编译跳过这一行：

if(sqlite3_prepare_v2(database1, [sqlStatement_userInfo UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK)

到这一行并且不起作用：

sqlite3_close(database1);

这是我的完整代码：

/*==================================================================
 METHOD FOR READING DATA FROM DATABASE
 ==================================================================*/
-(NSMutableArray *)readInformationFromDatabase
{
    array = [[NSMutableArray alloc] init];
    // Setup the database object
    sqlite3 *database2;
    // Open the database from the users filessytem
    if(sqlite3_open([[self DatabaseSqlite] UTF8String], &database2) == SQLITE_OK)
    {
        // Setup the SQL Statement and compile it for faster access
        //SQLIte Statement
        NSString *sqlStatement =[NSString stringWithFormat:@"Select ID from Table1 where ParentID = 0"];
        sqlite3_stmt *compiledStatement2;
        if(sqlite3_prepare_v2(database2, [sqlStatement UTF8String], -1, &compiledStatement2, NULL) == SQLITE_OK)
        {
            // Loop through the results and add them to the feeds array
            while(sqlite3_step(compiledStatement2) == SQLITE_ROW)
            {
                // Init the Data Dictionary
                _OwnID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement2, 0)];
            }
        }
        else
        {
            NSLog(@"No Data Found");
        }
        // Release the compiled statement from memory
        sqlite3_finalize(compiledStatement2);
    }
    sqlite3_close(database2);

    ThisParentID = _OwnID;
    do {
        // Setup the database object
        sqlite3 *database1;
        // Open the database from the users filessytem
        if(sqlite3_open([[self DatabaseSqlite] UTF8String], &database1) == SQLITE_OK)
        {
            // Setup the SQL Statement and compile it for faster access
            //SQLIte Statement
            NSString *sqlStatement_userInfo =[NSString stringWithFormat:@"Select * from Table1 ParentID = %@",ThisParentID];
            sqlite3_stmt *compiledStatement;
            if(sqlite3_prepare_v2(database1, [sqlStatement_userInfo UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK)
            {
                // Loop through the results and add them to the feeds array
                while(sqlite3_step(compiledStatement) == SQLITE_ROW)
                {
                    // Init the Data Dictionary
                    NSMutableDictionary *_dataDictionary=[[NSMutableDictionary alloc] init];
                    NSString *_recordName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];
                    NSString *_recordID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
                    NSString *_recordParentID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];
                    _recordBrotherID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)];
                    NSString *_recordChildID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 4)];
                    NSString *_recordType = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 5)];
                    NSString *_recordModified = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 6)];

                    ThisParentID = _recordID;

                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordName] forKey:@"Name"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordID] forKey:@"ID"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordParentID] forKey:@"ParentID"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordBrotherID] forKey:@"BrotherID"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordChildID] forKey:@"ChildID"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordType] forKey:@"Type"];
                    [_dataDictionary setObject:[NSString stringWithFormat:@"%@",_recordModified] forKey:@"Modified"];

                    [array addObject:_dataDictionary];
                }
            // Release the compiled statement from memory
            sqlite3_finalize(compiledStatement);
        }
        sqlite3_close(database1);
        }
        else
        {
            NSLog(@"NOT Found");
        }
    } while (![_recordBrotherID isEqualToString:@"0"]);

    return array;
}

Answer 1

您可能有更多机会使用SQLite包装器，如FMDB，或者更好，iActiveRecord（基于模型的包装器）。

Answer 2

我的朋友在写很多行代码时应该小心。这段代码是正确的，但在这段代码中有一点错误，这个错误就在这一行：

NSString *sqlStatement_userInfo =[NSString stringWithFormat:@"Select * from Table1 ParentID = %@",ThisParentID];

用于从SQlite读取数据，您应使用此代码：

“选择*来自TableName WHERE 列= SomeValue”

所以你应该改变你的代码并写下来：

NSString *sqlStatement_userInfo =[NSString stringWithFormat:@"Select * from Table1 Where ParentID = %@",ThisParentID];

我希望这对你有所帮助。

为什么不使用我的DataBase SQLite xcode

2 个答案: