Iphone 如何解决sqlite_准备错误

我知道当我使用'sqlite3_open'时，将打开一个新的数据库而不是我的sqlite文件。 因此，我使用“sqlite3\u open\u v2”修复了它。 但是现在，我仍然无法从我的文件中获取数据。有人能告诉我怎么做吗？ 非常感谢

这是我的密码： -

-

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应用程序内的checkAndCreateDatabase函数调用didFinishLaunchingWithOptions方法

之后

-(void) checkAndCreateDatabase
{

    BOOL success;


    NSFileManager *fileManager = [NSFileManager defaultManager];

    success = [fileManager fileExistsAtPath:databasePath];

    if(success) return;
    else
        printf("NO File found");

    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];

    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

    //[fileManager release];
}

-(void)readDataFromDatabase
{

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"freeway.sqlite"];
    sqlite3_stmt *compiledStatement;
    sqlite3 *database;
    if(sqlite3_open([path UTF8String], &database) == SQLITE_OK) {

        const char *sqlStatement;

        sqlStatement = "SELECT * FROM fee"; 

        sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL);

        printf("\nError===%s",sqlite3_errmsg(database));


        if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {


            while(sqlite3_step(compiledStatement) == SQLITE_ROW ) 

            {

                NSString *str_field1=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];

                NSString *str_field2=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];

                NSString *str_field3=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];

                NSString *str_field4=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)];


                // add str_field into array


            }

        }

        sqlite3_finalize(compiledStatement);


    }


    sqlite3_close(database);

}

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使用此NSLog（@“error=%d”，sqlite3_errcode（数据库））；获取错误代码我猜它无法捕获文件路径。但我不知道如何让它获取路径。没有错误消息吗？没有调试？没有迹象表明它出了什么问题？错误消息是“没有这样的表：费”“我认为它无法获得路径，而只能创建一个新路径。因此，在新文件中不能有表“费”。这只是我的猜测。我是初学者，不知道如何修复它。NSLog（@“%@”，databasePath）；结果：/Users/ai_erh/Library/Application Support/iPhone Simulator/5.1/Applications/1ACA32E4-D668-4A7A-9F42-84ED69999BD/Documents/freeway.sqlitehi，我尝试过你的教学，但仍然打印“失败”和“错误===没有这样的表格：费用“我确信我已将数据库文件复制到项目文档中。看起来它无法获取文件路径。我如何解决它？谢谢。我在上面添加了CheckandCreateDatabase代码。使用该函数而不是checkandcreatedatabase函数。仍然无法获取数据，输出为“错误===没有这样的表：费用”这样做/Users/Library/Application Support/iPhone Simulator/5.1/Applications在该用户项目文档中是否存在.sqlite文件，并检查您的表名该项目文档中是否存在区分大小写的.my freway.sqlite文件。sqlStatement可以在SQLite-Manager中成功。表名是正确的。我在这一点上困惑了3天。我快疯了。

(void)checkAndCreateDatabase
{

BOOL success;
NSFileManager *fileManager=[NSFileManager defaultManager];
success=[fileManager fileExistsAtPath:databasePath];
if (success) 
{  NSLog(@"success");
return;
}
else {
    NSLog(@"fail");
    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];       
    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];       
}
}

(void)readDataFromDatabase
sqlite3 *database;
fee = [[NSMutableArray alloc]init];

//if (sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK)
    if (sqlite3_open_v2([databasePath  UTF8String], &database, SQLITE_OPEN_READWRITE, NULL) == SQLITE_OK)       
    sqlite3_stmt *stmt;
    char *sql = "SELECT * FROM fee";     

    if (sqlite3_prepare_v2(database,sql,-1,&stmt,NULL) == SQLITE_OK){
        while (sqlite3_step(stmt) == SQLITE_ROW) {
            NSInteger pID = sqlite3_column_int(stmt, 0);
            NSString *pName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 1)];
            NSString *pName2 = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, 2)];

            Fee_Station *temp = [[Fee_Station alloc] initwithFCID:pID F_Name:pName Fmaileage:pName2];
            [fee addObject:temp];          
    }
    }
    else {
        NSLog(@"%s Prepare failure '%s' (%1d)", __FUNCTION__, sqlite3_errmsg(database), sqlite3_errcode(database));
    }     
    sqlite3_finalize(stmt);
}
sqlite3_close(database);
}

-(void) checkAndCreateDatabase
{

    BOOL success;


    NSFileManager *fileManager = [NSFileManager defaultManager];

    success = [fileManager fileExistsAtPath:databasePath];

    if(success) return;
    else
        printf("NO File found");

    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];

    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];

    //[fileManager release];
}

-(void)readDataFromDatabase
{

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"freeway.sqlite"];
    sqlite3_stmt *compiledStatement;
    sqlite3 *database;
    if(sqlite3_open([path UTF8String], &database) == SQLITE_OK) {

        const char *sqlStatement;

        sqlStatement = "SELECT * FROM fee"; 

        sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL);

        printf("\nError===%s",sqlite3_errmsg(database));


        if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {


            while(sqlite3_step(compiledStatement) == SQLITE_ROW ) 

            {

                NSString *str_field1=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];

                NSString *str_field2=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];

                NSString *str_field3=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];

                NSString *str_field4=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)];


                // add str_field into array


            }

        }

        sqlite3_finalize(compiledStatement);


    }


    sqlite3_close(database);

}