Image not retrieving from sql database in objective c

Question

Hello I have been trying to retrieve image from sql database named informationdb.sql but I am not able to,could anyone help with that.Here is my code

- (NSData*) LoadImagesFromSql
{
    NSData* data = nil;
    directoryPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    documentsDirectory = [directoryPaths objectAtIndex:0];
    NSString * databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"informationdb.sql"]];

    int openDatabaseResult = sqlite3_open_v2([databasePath UTF8String], &sqlite3DatabaseObject, SQLITE_OPEN_READWRITE , NULL);
    if (openDatabaseResult == SQLITE_OK) {
         const char* sqlite3Query = "SELECT PHOTO FROM PICTURES";
        int sqlite3Prepare = sqlite3_prepare_v2(sqlite3DatabaseObject, sqlite3Query, -1, &sqlite3Statement, NULL);
    if( sqlite3Prepare == SQLITE_OK )
    {
        const char *myData = sqlite3_column_blob(sqlite3Statement, 1);
        int myDataSize = sqlite3_column_bytes(sqlite3Statement, 1);
        data = [NSData dataWithBytes:myData length:myDataSize];
        sqlite3_step(sqlite3Statement);
    }
         sqlite3_finalize(sqlite3Statement);
    }
    sqlite3_close(sqlite3DatabaseObject);
    return data;

}

Thank you.

Simple questions: Do you pass the two if test? What's wrong exactly with your code? Also, please name your method starting with a lower case. — Larme
– Larme, Commented Apr 11, 2017 at 12:24
@simeryn please refer this link stackoverflow.com/questions/43339680/… — Shahrukh
– Shahrukh, Commented Apr 11, 2017 at 12:31
yes the if test was successful but "myData" is showing NULL. — Simeryn Denis
– Simeryn Denis, Commented Apr 11, 2017 at 12:32

Jigar · Accepted Answer · 2017-04-11 13:41:22Z

2

first delete database in document directory than change all three method to my code

-(void)database
{

    directoryPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    documentsDirectory = [directoryPaths objectAtIndex:0];
    NSString * databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"informationdb.sql"]];
    NSLog(@"database path=%@",databasePath);
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if ([fileManager fileExistsAtPath:databasePath] == NO) {
        const char *dbPath = [databasePath UTF8String];
        if (sqlite3_open(dbPath, &sqlite3DatabaseObject)== SQLITE_OK) {
            char * errorMessage;
            const char *sqlite3Query = "CREATE TABLE IF NOT EXISTS  PICTURES (PHOTO BLOB,Id integer PRIMARY KEY)";
            if (sqlite3_exec(sqlite3DatabaseObject, sqlite3Query, NULL, NULL, &errorMessage)!= SQLITE_OK) {
                NSLog(@"failed = %@",sqlite3DatabaseObject);
            }
            sqlite3_close(sqlite3DatabaseObject);
        }else{
            NSLog(@"failed to create database");
        }
    }
}



- (void) SaveImagesToSql: (NSData*) imgData  {

    directoryPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    documentsDirectory = [directoryPaths objectAtIndex:0];
    NSString * databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"informationdb.sql"]];
    NSLog(@"database path=%@",databasePath);
    const char* sqlite3Query = "INSERT INTO PICTURES (PHOTO) VALUES (?)";
    int openDatabaseResult = sqlite3_open_v2([databasePath UTF8String], &sqlite3DatabaseObject, SQLITE_OPEN_READWRITE , NULL);
    if (openDatabaseResult == SQLITE_OK) {
        int sqlite3Prepare = sqlite3_prepare_v2(sqlite3DatabaseObject, sqlite3Query, -1, &sqlite3Statement, NULL);
        if( sqlite3Prepare == SQLITE_OK ) {
            sqlite3_bind_blob(sqlite3Statement, 1, [imgData bytes], [imgData length], SQLITE_TRANSIENT);
            sqlite3_step(sqlite3Statement);
        }
        else
        {
            NSLog(@"Error is: %s", sqlite3_errmsg(sqlite3DatabaseObject));
        }
        sqlite3_finalize(sqlite3Statement);

    }
    else NSLog( @"Error is:  %s", sqlite3_errmsg(sqlite3DatabaseObject) );
    sqlite3_close(sqlite3DatabaseObject);
}


- (NSData*)LoadImagesFromSql
{
    NSData* data = nil;
    directoryPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    documentsDirectory = [directoryPaths objectAtIndex:0];
    NSString * databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"informationdb.sql"]];
    sqlite3_stmt *compiledStmt;
    sqlite3 *db;
    int i = 1;
    if(sqlite3_open([databasePath UTF8String], &db)==SQLITE_OK){
        NSString *insertSQL = [NSString stringWithFormat:@"SELECT PHOTO FROM PICTURES WHERE Id = %d",i];
        if(sqlite3_prepare_v2(db,[insertSQL cStringUsingEncoding:NSUTF8StringEncoding], -1, &compiledStmt, NULL) == SQLITE_OK) {
            while(sqlite3_step(compiledStmt) == SQLITE_ROW) {

                int length = sqlite3_column_bytes(compiledStmt, 0);
                data = [NSData dataWithBytes:sqlite3_column_blob(compiledStmt, 0) length:length];

                NSLog(@"Length : %lu", (unsigned long)[data length]);

//                if(imageData == nil)
//                    NSLog(@"No image found.");
//                else
//                    imgView.image = [UIImage imageWithData:imageData];
            }
        }
        sqlite3_finalize(compiledStmt);
    }
    sqlite3_close(db);
    return data;
}

answered Apr 11, 2017 at 13:41

Jigar

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5 Comments

Jigar Over a year ago

@Simeryn Denis check my answer

Simeryn Denis Over a year ago

it says table doesn't exist.

Simeryn Denis Over a year ago

no buddy still it's not working.I deleted these 3 methods and replace with your code. It's SAYING Error is: no such table: PICTURES

Jigar Over a year ago

@SimerynDenis debug create table function and check PICTURES table create or not

Jigar Over a year ago

Let us continue this discussion in chat.

Simeryn Denis · Accepted Answer · 2017-04-12 06:19:00Z

2

solved it by this:

- (NSData*) LoadImagesFromSql
{
    directoryPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    documentsDirectory = [directoryPaths objectAtIndex:0];
    NSString * databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"informationdb.sql"]];

    NSData* data = nil;
    //  int i=0;

    NSString* sqlite3Query = [NSString stringWithFormat:@"SELECT PHOTO FROM PICTURES "];

    int openDatabaseResult = sqlite3_open_v2([databasePath UTF8String], &sqlite3DatabaseObject, SQLITE_OPEN_READWRITE , NULL);
    if (openDatabaseResult == SQLITE_OK)
    {
        int sqlite3Prepare = sqlite3_prepare_v2(sqlite3DatabaseObject, [sqlite3Query UTF8String], -1, &sqlite3Statement, NULL);
        if( sqlite3Prepare == SQLITE_OK )
        {
            while (sqlite3_step(sqlite3Statement) == SQLITE_ROW) {
                const char *myData = sqlite3_column_blob(sqlite3Statement, 0);
                int myDataSize = sqlite3_column_bytes(sqlite3Statement, 0);
                data = [NSData dataWithBytes:myData length:myDataSize];
            }
            sqlite3_finalize(sqlite3Statement);
        }
    }
    sqlite3_close(sqlite3DatabaseObject);
    return data;

}

and updated viewWillAppear as :

-(void)viewWillAppear:(BOOL)animated{

    dbmClass = [[DBManager alloc]init];
    if (imgPic.image != nil) {
        imgPic.image = nil;
    }
    imgPic.image = [UIImage imageWithData:[dbmClass LoadImagesFromSql]];
    NSLog(@"%@",[dbmClass LoadImagesFromSql]);


}

answered Apr 12, 2017 at 6:19

Simeryn Denis

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2 Comments

Jigar Over a year ago

in your code try to save 2 or more image than check.you does not get image in imageview

Simeryn Denis Over a year ago

No it works i tried saving 2 images it works perfectly.The method every time gets the last image which I upload in the database.

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