如何将图像添加到 sql 中？我已将图像转换为 NSdata

Question

这是查询

-(void)runQuery:(const char *)query isQueryExecutable:(BOOL)queryExecutable{
// Create a sqlite object.
sqlite3 *sqlite3Database;

// Set the database file path.
NSString *databasePath = [self.documentsDirectory stringByAppendingPathComponent:self.databaseFilename];

// Initialize the results array.
if (self.arrResults != nil) {
    [self.arrResults removeAllObjects];
    self.arrResults = nil;
}
self.arrResults = [[NSMutableArray alloc] init];

// Initialize the column names array.
if (self.arrColumnNames != nil) {
    [self.arrColumnNames removeAllObjects];
    self.arrColumnNames = nil;
}
self.arrColumnNames = [[NSMutableArray alloc] init];


// Open the database.
BOOL openDatabaseResult = sqlite3_open([databasePath UTF8String], &sqlite3Database);
if(openDatabaseResult == SQLITE_OK) {
    // Declare a sqlite3_stmt object in which will be stored the query after having been compiled into a SQLite statement.
    sqlite3_stmt *compiledStatement;

    // Load all data from database to memory.
    BOOL prepareStatementResult = sqlite3_prepare_v2(sqlite3Database, query, -1, &compiledStatement, NULL);
    if(prepareStatementResult == SQLITE_OK) {
        // Check if the query is non-executable.
        if (!queryExecutable){
            // In this case data must be loaded from the database.

            // Declare an array to keep the data for each fetched row.
            NSMutableArray *arrDataRow;

            // Loop through the results and add them to the results array row by row.
            while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
                // Initialize the mutable array that will contain the data of a fetched row.
                arrDataRow = [[NSMutableArray alloc] init];

                // Get the total number of columns.
                int totalColumns = sqlite3_column_count(compiledStatement);

                // Go through all columns and fetch each column data.
                for (int i=0; i<totalColumns; i++){
                    // Convert the column data to text (characters).
                    char *dbDataAsChars = (char *)sqlite3_column_text(compiledStatement, i);

                    // If there are contents in the currenct column (field) then add them to the current row array.
                    if (dbDataAsChars != NULL) {
                        // Convert the characters to string.
                        [arrDataRow addObject:[NSString  stringWithUTF8String:dbDataAsChars]];
                    }

                    // Keep the current column name.
                    if (self.arrColumnNames.count != totalColumns) {
                        dbDataAsChars = (char *)sqlite3_column_name(compiledStatement, i);
                        [self.arrColumnNames addObject:[NSString stringWithUTF8String:dbDataAsChars]];
                    }
                }

                // Store each fetched data row in the results array, but first check if there is actually data.
                if (arrDataRow.count > 0) {
                    [self.arrResults addObject:arrDataRow];
                }
            }
        }
        else {
            // This is the case of an executable query (insert, update, ...).

            // Execute the query.
            BOOL executeQueryResults = sqlite3_step(compiledStatement);
            if (executeQueryResults == SQLITE_DONE) {
                // Keep the affected rows.
                self.affectedRows = sqlite3_changes(sqlite3Database);

                // Keep the last inserted row ID.
                self.lastInsertedRowID = sqlite3_last_insert_rowid(sqlite3Database);
            }
            else {

                NSLog(@"DB Error: %s", sqlite3_errmsg(sqlite3Database));
            }
        }
    }
    else {

        NSLog(@"%s", sqlite3_errmsg(sqlite3Database));
    }


    sqlite3_finalize(compiledStatement);

}


sqlite3_close(sqlite3Database);
}

我正在插入值

NSString *query;
if (self.recordIDToEdit == -1) {
    query = [NSString stringWithFormat:@"insert into peopleInfo values(null, '%@', '%@', %d )", self.txtFirstname.text, self.txtLastname.text, [self.txtAge.text intValue]];

}
else{
    query = [NSString stringWithFormat:@"update peopleInfo set firstname='%@', lastname='%@', age=%d where peopleInfoID=%d", self.txtFirstname.text, self.txtLastname.text, self.txtAge.text.intValue, self.recordIDToEdit];
}

Answer 1

您只是不需要在数据库中添加图像。将您的图像放在 HomeDirectory 中，然后将 ImageUrl 保存在数据库中。这样您就可以轻松管理它。

Answer 2

我给你详细的答案。如果要将图像保存到数据库中，请先将图像保存到文档目录中，然后将文档目录路径传递给 SQLite db。

我有单独的文件（NSObject 类）用于将图像保存到文档目录中。

PhotoPath.h

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface PhotoPath : NSObject

+(NSString*)getSavedPhotoPath:(UIImage*)image;
+(NSString*)getphotopath;
+(NSString *)applicationDocumentsdirectory;
+(void)ensureDirs:(NSString*)path;
+(NSString*)getCurrentTime;
+(NSString*)getCurrentDate;

@end 

PhotoPath.m

#import "PhotoPath.h"

@implementation PhotoPath

+(NSString*)getSavedPhotoPath:(UIImage*)image
{
    NSString *path =nil;
    NSString *file_name = [[self getCurrentDate]stringByAppendingString:[self getCurrentTime]];
    file_name =[file_name stringByAppendingPathExtension:@"jpeg"];
    path =[[self getphotopath]stringByAppendingPathComponent:file_name];
    NSData *imgData =UIImageJPEGRepresentation(image, 0.4);
    [imgData writeToFile:path atomically:YES];
    return path;
}

+(NSString*)getphotopath
{
    //CREATE PHOTO PATH FOR SAVED IMAGES
    NSString *path = [[self applicationDocumentsdirectory]stringByAppendingPathComponent:@"photosOne"];
    [self ensureDirs:path];
    return path;
}

+(NSString *)applicationDocumentsdirectory
{
    int i=0;
    NSArray *paths1 =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *basePath =([paths1 count] >i) ? [paths1 objectAtIndex:i] : nil;
    return basePath;
}

+(void)ensureDirs:(NSString*)path
{
    //Get Directory in FileManager
    NSFileManager *fileManager =[NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:path])
     return;
   [fileManager createDirectoryAtPath:path  withIntermediateDirectories:NO attributes:nil error:nil];
}

+(NSString*)getCurrentTime
{
    //Get Current Time for saving Images
    NSString *path =nil;
    NSDateFormatter *timeFormatter =[[NSDateFormatter alloc]init];
    [timeFormatter setDateFormat:@"HH:mm:ss.SSS"];
    NSDate *now = [[NSDate alloc]init];
    NSString *str_time = [timeFormatter stringFromDate:now];
    NSString *curr_time;
    curr_time =[str_time stringByReplacingOccurrencesOfString:@"." withString:@""];
    path = [NSString stringWithFormat:@"%@",curr_time];
    return  path;
}

+(NSString*)getCurrentDate
{
    NSString *today =nil;
    NSDateFormatter *dateFormatter1;
    dateFormatter1 =[[NSDateFormatter alloc]init];
    [dateFormatter1 setDateFormat:@"d MMM yyyy"];
    NSDate *now =[[NSDate alloc]init];
    NSLocale *usLocale =[[NSLocale alloc]initWithLocaleIdentifier:@"en_US"];
    [dateFormatter1 setLocale:usLocale];
    NSString *str_date =[dateFormatter1 stringFromDate:now];
    today=[NSString stringWithFormat:@"%@",str_date];
    return today;
}

@end

ViewController.h

#import <UIKit/UIKit.h>
#import "PhotoPath.h"
@interface ViewController : UIViewController<UIImagePickerControllerDelegate,UINavigationControllerDelegate>
{
   PhotoPath *path;
}
@property(nonatomic,retain)NSMutableArray *arrImg;
@property (strong, nonatomic) IBOutlet UIImageView *imgPick;
- (IBAction)actionSaveImageIntoSQLite:(id)sender;
@end

ViewController.m

#import "ViewController.h"
interface ViewController ()
@end
@implementation ViewController
@synthesize arrImg,imgPick;

- (void)viewDidLoad
{
  [super viewDidLoad];
   UITapGestureRecognizer *tapImage =[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapDetect)];
   tapImage.numberOfTapsRequired =1;
   tapImage.numberOfTouchesRequired =1;
   imgPick.userInteractionEnabled =YES;
   [imgPick addGestureRecognizer:tapImage];
}

-(void)tapDetect
{
    UIImagePickerController *picker =[[UIImagePickerController alloc]init];
    picker.sourceType =UIImagePickerControllerSourceTypePhotoLibrary;
    picker.delegate =self;
    [self presentViewController:picker animated:NO completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage *image=[info objectForKey:@"UIImagePickerControllerOriginalImage"];
    imgPick.image=image;
    [arrImg addObject:image];
    picker.delegate =self;
    [picker dismissViewControllerAnimated:YES completion:nil];
}
- (IBAction)actionSaveImageIntoSQLite:(id)sender
{
   NSMutableArray *arrAllImgPath =[[NSMutableArray alloc]init];
   for (UIImage *img in arrImg)
   {
      NSString *strImgPath =[PhotoPath getSavedPhotoPath:img];
      [arrAllImgPath addObject:strImgPath];
   }
   NSLog(@"The path is - %@",arrAllImgPath);
   for (int i=0; i<[arrAllImgPath count]; i++)
   {
      NSString *strImgPathURL = [arrAllImgPath objectAtIndex:i];
      [SqliteDB insertDataintoDB:strImgPathURL];
   }
}
@end

当你从 SQLite DB 获取图像时

NSString *localPath=[NSString stringWithFormat:@"%@",[arrSQLiteDBImg objectAtIndex:i]];
NSURL *urlString=[NSURL fileURLWithPath:localPath];
NSData *data = [NSData dataWithContentsOfURL:urlString];
UIImage *img = [[UIImage alloc] initWithData:data] ;