Question

我在我的应用程序中使用了sqlite DB，我需要调用两个同时进行的查询，但是我给出了错误：由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'错误准备语句'

在按钮事件发生后从DB中选择行和在DB中插入行时，我每隔10秒运行一次计时器。

我的代码段为：

viewWillAppear中的

：

int result2 = sqlite3_open([dbPath UTF8String], &database);
if (result2 != SQLITE_OK) {
    NSLog(@"Failure in connecting to the database with result %d",result2);
}
else {
    NSLog(@ "Succesfully opened connection to DB") ;

}

和viewWillDisappear：

int result = sqlite3_close(database);
if (result != SQLITE_OK){
    NSLog(@"Failure in closing connection to database. Result %d",result);
}
else {
    NSLog(@"Successfully closed DB connection") ;
}

Inserting rows：

NSString *queryInsert = [NSString stringWithFormat: @"insert into mail_snoozlist (msgBody,msgSubject, msgSender,msgTo,msgDate,snoozTime) values('%@','%@','%@','%@','%@','%@')",strBody,msgSub,msgFrom,msgTo,strMsgDate,stringFromDate];

    NSLog(@"queryInsert:%@",queryInsert);

    const char *sql = [queryInsert UTF8String];

    if(sqlite3_prepare_v2(database, sql, -1, &statement, NULL) == SQLITE_OK) {
        sqlite3_step(statement);
        sqlite3_reset(statement);

    } else {

        NSAssert1(0,@"error preparing statement",sqlite3_errmsg(database));
        return;
    }

    sqlite3_finalize(statement);

和Selecting rows：

NSString *querySQL2 = [NSString stringWithFormat: @"Select * from mail_snoozlist WHERE snoozTime = '%@'",_snoozTime];

    NSLog(@"querySql:%@",querySQL2);

    if (sqlite3_prepare_v2(database, [querySQL2 UTF8String], -1, &statement, NULL) == SQLITE_OK)
    {

        while (sqlite3_step(statement) == SQLITE_ROW)
        {
            Message *obj = [[Message alloc] init];

            NSString *msgBody=[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
            obj.msgBody= msgBody;

            NSString *msgSub=[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
            obj.msgSub= msgSub;

            NSString *msgSender=[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 3)];
            obj.msgFrom= msgSender;

            NSString *msgTo=[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 4)];
            obj.msgTo= msgTo;

            NSString *msgDate=[[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];
            obj.msgDate= msgDate;

            [listOfItems addObject:obj];

            [self.tableView reloadData];
        }

        sqlite3_reset(statement);
        sqlite3_finalize(statement);

任何人都可以帮我解决这个问题。

谢谢！

Answer 1

您应该更改NSAssert语句以包含错误消息：

NSAssert1(0, @"error preparing statement: %s", sqlite3_errmsg(database));

一旦你这样做，你应该得到一个有意义的回应，这将有助于你诊断问题。

不查看sqlite3_errmsg消息，很难诊断问题。它可能像列名或表名中的拼写错误一样简单，也可能因为找不到表而复杂，因为在创建数据库时未找到该数据库，因此创建了一个空白数据库（没有该表）。在我们看到错误消息之前很难说。

顺便说一句，您不应该使用stringWithFormat构建SQL，因为您将自己打开SQL注入攻击，并且如果其中任何文本值中包含撇号，则会出现问题。您应该使用?占位符而不是printf样式格式化程序，然后使用sqlite3_bind_text调用将值绑定到这些列：

NSString *queryInsert = @"insert into mail_snoozlist (msgBody,msgSubject, msgSender,msgTo,msgDate,snoozTime) values(?, ?, ?, ?, ?, ?)";

if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error preparing statement: %s",sqlite3_errmsg(database));
    return;
}

// for these 6 sqlite3_bind function calls, if any of these strings can be `nil`, then you'd
// want to call sqlite3_bind_null if that's the case, rather than sqlite3_bind_text

if (sqlite3_bind_text(statement, 1, [strBody UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 1: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_bind_text(statement, 2, [msgSub UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 2: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_bind_text(statement, 3, [msgFrom UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 3: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_bind_text(statement, 4, [msgTo UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 4: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_bind_text(statement, 5, [strMsgDate UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 5: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_bind_text(statement, 6, [stringFromDate UTF8String], -1, NULL) != SQLITE_OK) {
    NSAssert1(0,@"error binding 6: %s",sqlite3_errmsg(database));
    sqlite3_finalize(statement);
    return;
}

if (sqlite3_step(statement) != SQLITE_DONE) {
    NSAssert1(0,@"error stepping: %s",sqlite3_errmsg(database));
}

sqlite3_finalize(statement);

我用insert语句说明了这个问题，但同样也应该用select语句来解决。

Answer 2

添加这两个方法，并在插入和选择之前用insert方法调用它们，

 - (void) createEditableCopyOfDatabaseIfNeeded
{


    BOOL success;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSError *error;
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"dbname.sqlite"];
    success = [fileManager fileExistsAtPath:writableDBPath];
    if (success) return;
    //{

    NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"dbname.sqlite"];

    success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
    // }
    if (!success)
    {
        NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]);
    }
}


- (void)initializeDatabase
 {



NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"dbname.sqlite"];
sqlite3_open([path UTF8String], &database);
}

iOS：Sqlite数据库错误：由于未捕获的异常'NSInternalInconsistencyException'而终止应用程序，原因：'错误准备语句'

2 个答案: