@lifemoveson

@lifemoveson

我曾经对您的代码进行调试，发现该函数

I used to your code to debug and found that the function

sqlite3_prepare_v2(database, insert_product_sql, -1, &product_statement, nil)

每次返回1，它对应于您在所需位置缺少的数据库.

returns 1 everytime and it corresponds to your missing database at the desired location.

我会建议您做一个这样的功能

What I will suggest to you is make a function such as this

-(void)checkAndCreateDatabase{
    databaseName = @"MasterDB.sqlite";
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDir = [documentPaths objectAtIndex:0];
    databasePath = [documentsDir stringByAppendingPathComponent:databaseName];
    NSLog(@"database path %@",databasePath);
    BOOL success;

    // Create a FileManager object, we will use this to check the status
    // of the database and to copy it over if required
    NSFileManager *fileManager = [NSFileManager defaultManager];

    // Check if the database has already been created in the users filesystem
    success = [fileManager fileExistsAtPath:databasePath];

    // If the database already exists then return without doing anything
    if(success) return;

    // If not then proceed to copy the database from the application to the users filesystem

    // Get the path to the database in the application package
    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];

    // Copy the database from the package to the users filesystem
    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];
    //[fileManager release];

    // Now we can add new table

    sqlite3 *database;
    sqlite3_stmt *statement; 
    if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK)
    {

        NSString *sqlQuery = [NSString stringWithFormat:@"CREATE TABLE IF NOT EXISTS tbl_Login (userId integer PRIMARY KEY,userName text,password text);"] ;
        const char *create_stmt = [sqlQuery UTF8String];
        sqlite3_prepare_v2(database, create_stmt, -1, &statement, NULL);

        if(sqlite3_step(statement)==SQLITE_DONE) 
        {
            NSLog(@"Table created");            
        }
        else 
        {
            NSLog(@"Table could not be created");
        }   
        // Release the compiled statement from memory
        sqlite3_finalize(statement);    
        sqlite3_close(database);
    }
}

设置类变量databasePath并确保在运行任何数据库查询之前，该数据库实际上存在于应用程序的文档目录中.您可以在应用程序委托

Which sets your class variable databasePath and ensure that before you run any database query the database is actually present in the applcation's document directory. You can call this function in application delegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
//Other code 
[self checkAndCreateDatabase];

}

当您进行任何数据库调用时，请使用此

When you make any database call use this

const char *dbpath = [databasePath UTF8String];
    if (sqlite3_open(dbpath , &database) == SQLITE_OK) {
//Code to perform insert operations
 }

我建议您为执行的所有数据库操作编写一个单独的类，而不是调用该类函数以实现所需的功能.这将节省您重写代码的工作.

i would suggest you to write a separate class for all the database operation that you perform and instead call the class function to achieve the desired functionality. This will save your efforts from rewriting the code.

您可以为此使用FMDB包装器，该包装器可以找到

You can make use of FMDB wrapper for this which you can find here

希望这会有所帮助:-)

Hope this helps :-)