Sqlite3_step（）保持对此查询返回SQLITE_MISUSE。任何指针？ [英] Sqlite3_step() keeps returning SQLITE_MISUSE on this query. Any pointers?

问题描述

我试图在viewDidLoad例程中打开一个sqlite数据库，并尝试发送一个sql查询到db，但sqlite_step（）每次都失败。我不知道这里有什么问题。我只是尝试这是一个hello世界尝试sqlite3。

  #importRootViewController.h
 #import sqlite3.h
 
 static sqlite3_stmt * statement = nil; 
 
 @implementation RootViewController 
 
  - （void）viewDidLoad {
 [super viewDidLoad]; 
 NSString * dbname = @name.sqlite; 
 sqlite3 * database; 
 int success; 
 
 //取消注释以下行以在此视图控制器的导航栏中显示编辑按钮。 
 // self.navigationItem.rightBarButtonItem = self.editButtonItem; 
 NSArray * paths = NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）; 
 NSString * documentsDirectory = [paths objectAtIndex：0]; 
 NSString * path = [documentsDirectory stringByAppendingPathComponent：dbname]; 
 //打开数据库。数据库是在应用程序外部准备的。 
 success = sqlite3_open（[path UTF8String]，& database）; 
 if（success == SQLITE_OK）{
 NSLog（@数据库打开成功：％d，成功）; 
} else {
 //即使打开失败，调用close以正确清理资源。 
 sqlite3_close（database）; 
 NSLog（@数据库打开失败：％d，成功）; 
 //额外的错误处理，适当的... 
} 
 if（statement == nil）{
 const char * sql =insert into name（nid，name） values（6，'testname'）;; 
 success = sqlite3_prepare_v2（database，sql，-1，& statement，NULL）; 
 NSLog（@query prepare status：％d，success）; 
 if（success！= SQLITE_OK）{
} 
} 
 
 success = sqlite3_step（statement）; //这里的事情失败，因为所有调用返回ok 
 NSLog（@query step status：％d，success）; 
 if（success！= SQLITE_DONE）{
} 
 sqlite3_reset（statement）; 
 sqlite3_close（database）; 
} 
 ... 
  

在哪里我可能是错的。感谢您的时间。

解决方案

我这样做，但它仍然不工作，因为没有什么显示在控制台。

 
 #importRootViewController.h
 #importFMDatabase.h
 
 @实现RootViewController 
 
  - （void）viewDidLoad {
 [super viewDidLoad]; 
 NSString * dbname = @name.sqlite; 
 NSArray * paths = NSSearchPathForDirectoriesInDomains（NSDocumentDirectory，NSUserDomainMask，YES）; 
 NSString * documentsDirectory = [paths objectAtIndex：0]; 
 NSString * path = [documentsDirectory stringByAppendingPathComponent：dbname]; 
 FMDatabase * database = [FMDatabase databaseWithPath：path]; 
 FMResultSet * rs = [database executeQuery：@select * from name;]; 
 while（[rs next]）{
 NSLog（@％d％@，
 [rs intForColumn：@nid]，
 [rs stringForColumn：@名称]）; 
} 
 [database close]; 
} 
 ... 
 

对不起，但无法使用代码块，因此再次使用pre 。

编辑：当我在FMDB中打开日志时，像这样：

 
 FMDatabase * database = [FMDatabase databaseWithPath：path]; 
 
 [database setLogsErrors：YES]; 
 
 if（！[database open]）{
 NSLog（@无法打开db。 
} else {
 NSLog（@DB Open ....）; 
} 
 FMResultSet * rs = [database executeQuery：@select * from'name';]; 
 while（[rs next]）{
 //只是打印出我们有多种格式。 
 NSLog（@％d％@，
 [rs intForColumn：@nid]，
 [rs stringForColumn：@name]）; 
} 
 [database close]; 
 

...，我在控制台中看到：

 
 [session started at 2010-09-07 15:38:16 +0530。] 
 2010-09-07 15：38：19.178 MyDBTry [13670：207] DB打开.... 
 2010-09-07 15：38：19.181 MyDBTry [13670：207] DB错误：1没有这样的表：名称
 2010-09-07 15：38：19.182 MyDBTry [13670：207] DB查询：select * from name; 
 

I am trying to open a sqlite db in the viewDidLoad routine and trying to send a sql query through to the db, but the sqlite_step() fails every time. I am not sure what's wrong here. I am just trying this as a hello world attempt at sqlite3.

#import "RootViewController.h"
#import "sqlite3.h"

static sqlite3_stmt *statement = nil;

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    NSString *dbname = @"name.sqlite";
    sqlite3 *database;
    int success;

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem;
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:dbname];
    // Open the database. The database was prepared outside the application.
    success = sqlite3_open([path UTF8String], &database);
    if (success == SQLITE_OK) {
        NSLog(@"database opening successful : %d", success);
    } else {
        // Even though the open failed, call close to properly clean up resources.
        sqlite3_close(database);
        NSLog(@"database opening failed : %d", success);
        // Additional error handling, as appropriate...
    }
    if (statement == nil) {
        const char *sql = "insert into name(nid, name) values(6, 'testname');";
        success = sqlite3_prepare_v2(database, sql, -1, &statement, NULL);
        NSLog(@"query prepare status: %d", success);
        if (success != SQLITE_OK) {
        }
    }

    success = sqlite3_step(statement); //things fail here, as all calls above return ok
    NSLog(@"query step status: %d", success);
    if (success != SQLITE_DONE) {
    }
    sqlite3_reset(statement);
    sqlite3_close(database);
}
...

It would be great if anyone could point me out where I might be wrong. Thanks for your time already.

解决方案

I did this but it still doesn't work, as in nothing shows up in the Console.

#import "RootViewController.h"
#import "FMDatabase.h"

@implementation RootViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    NSString *dbname = @"name.sqlite";
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:dbname];
    FMDatabase * database = [FMDatabase databaseWithPath:path];
    FMResultSet *rs = [database executeQuery:@"select * from name;"];
    while ([rs next]) {
        NSLog(@"%d %@",
              [rs intForColumn:@"nid"],
              [rs stringForColumn:@"name"]);
    }
    [database close];
}
...

And sorry but am unable to use the code block, so using a pre again.

Edit: When I turn logging on in FMDB, like this:

    FMDatabase * database = [FMDatabase databaseWithPath:path];

    [database setLogsErrors:YES];

    if (![database open]) { 
        NSLog(@"Could not open db."); 
    } else { 
        NSLog(@"DB Open...."); 
    }
    FMResultSet *rs = [database executeQuery:@"select * from 'name';"];
    while ([rs next]) {
        // just print out what we've got in a number of formats.
        NSLog(@"%d %@",
              [rs intForColumn:@"nid"],
              [rs stringForColumn:@"name"]);
    }
    [database close];

..., I get this in the Console:

[Session started at 2010-09-07 15:38:16 +0530.]
2010-09-07 15:38:19.178 MyDBTry[13670:207] DB Open....
2010-09-07 15:38:19.181 MyDBTry[13670:207] DB Error: 1 "no such table: name"
2010-09-07 15:38:19.182 MyDBTry[13670:207] DB Query: select * from name;

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