Storing and retrieving data from sqlite database

Question

I am building an app which contains a form in one view,in which the user fills all the fields and when he clicks the save button the data must be saved in to database and af

Answer 1

You should use FMDB to reduce the complexity of your code.

It is an Objective-C wrapper around SQLite.

FMDB on github

Answer 2

you can check whether your data has been saved or not by checking the database table. Go to Users>your computer name>Library>Application support>iphone Simulator>4.3(your version of ios)>Application.. Then look for your Application,go to documents and open the sqlite file. Here you can see the data.

Answer 3

First you should create the sqlite3 database file (check this link), then you should include it into your project. Now to connect to it you can use the following code:

#pragma mark -
#pragma mark Create/Load Database
+ (void)createEditableCopyOfDatabaseIfNeeded {
    // First, test for existence.
    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString * documentsDirectory = [paths objectAtIndex:0];
    NSString * writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"DATABASENAME.DB"];

    BOOL success;
    NSFileManager * fileManager = [NSFileManager defaultManager];
    success = [fileManager fileExistsAtPath:writableDBPath];
    if (success) {
        return;
    }

    // The writable database does not exist, so copy the default to the appropriate location.
    NSError * error;
    NSString * defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"DATABASENAME.DB"];
    success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
    if (!success) {
        NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]);
    }
}
+ (sqlite3 *)getDBConnection {
    [DatabaseController createEditableCopyOfDatabaseIfNeeded];

    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString * documentsDirectory = [paths objectAtIndex:0];
    NSString * path = [documentsDirectory stringByAppendingPathComponent:@"DATABASENAME.DB"];

    // Open the database. The database was prepared outside the application.
    sqlite3 * newDBConnection;
    if (sqlite3_open([path UTF8String], &newDBConnection) == SQLITE_OK) {
        //NSLog(@"Database Successfully Opened :)");
    } else {
        //NSLog(@"Error in opening database :(");
    }
    return newDBConnection;
}

then to insert a record you can use this code:

+ (void)insertEvent:(Event *)newEvent {
    sqlite3 * connection = [DatabaseController getDBConnection];
    const char * text = "INSERT INTO Event (Serial, Name, Date) VALUES (?, ?, ?)";
    sqlite3_stmt * insert_statement;
    int prepare_result = sqlite3_prepare_v2(connection, text, -1, &insert_statement, NULL);
    if ((prepare_result != SQLITE_DONE) && (prepare_result != SQLITE_OK)) {
        // Error
        sqlite3_close(connection);
        return;
    }

    sqlite3_bind_int(insert_statement, 1, newEvent.Serial);
    sqlite3_bind_text(insert_statement, 2, [newEvent.Name UTF8String], -1, SQLITE_TRANSIENT);
    sqlite3_bind_double(insert_statement, 3, [newEvent.Date timeIntervalSince1970]);

    int statement_result = sqlite3_step(insert_statement);
    if ((statement_result != SQLITE_DONE) && (statement_result != SQLITE_OK)) {
        //Error
        sqlite3_close(connection);
        return;
    }

    sqlite3_finalize(insert_statement);

    // Get the Id of the inserted event
    int rowId = sqlite3_last_insert_rowid(connection);
    newEvent.Id = rowId;

    sqlite3_close(connection);
}

now to get an event:

+ (Event *)getEventById:(int)id {
    Event * result = nil;
    sqlite3 * connection = [DatabaseController getDBConnection];

    const char * text = "SELECT * FROM Event WHERE Id = ?";
    sqlite3_stmt * select_statement;

    int prepare_result = sqlite3_prepare_v2(connection, text, -1, &select_statement, NULL);
    if ((prepare_result != SQLITE_DONE) && (prepare_result != SQLITE_OK)) {
        // error
        sqlite3_close(connection);
        return result;
    }

    sqlite3_bind_int(select_statement, 1, id);

    if (sqlite3_step(select_statement) == SQLITE_ROW) {
        result = [[[Event alloc] init] autorelease];

        result.Id = sqlite3_column_int(select_statement, 0);
        result.Serial = sqlite3_column_int(select_statement, 1);
        result.Name = (((char *) sqlite3_column_text(select_statement, 2)) == NULL)? nil:[NSString stringWithUTF8String:((char *) sqlite3_column_text(select_statement, 2))];
        result.Date = [NSDate dateWithTimeIntervalSince1970:sqlite3_column_double(select_statement, 3)];
    }
    sqlite3_finalize(select_statement);

    sqlite3_close(connection);
    return (result);
}

Answer 4

Here is a blog post that should get you pointed in the right direction, pretty useful to me so sharing it with you.:P

http://dblog.com.au/iphone-development-tutorials/iphone-sdk-tutorial-reading-data-from-a-sqlite-database/

Answer 5

This code used for storing data and retriving data from sqlite data base First you just add sqlite3 frame work after that write bellow code in objective-c

ViewController.h

   #import <UIKit/UIKit.h>
   #import "sqlite3.h"
  @interface ViewController : UIViewController

  @property (weak, nonatomic) IBOutlet UITextField *firstName;
  @property (weak, nonatomic) IBOutlet UITextField *lastName;
  @property (weak, nonatomic) IBOutlet UITextField *state;
 @property (weak, nonatomic) IBOutlet UITextField *mobileNum;

 - (IBAction)saveButton:(id)sender;


- (IBAction)featchButton:(id)sender;
 @property (weak, nonatomic) IBOutlet UILabel *label;

 @property NSString *myDatabase;
 @property sqlite3 *marksDB;

ViewController.m

         #import "ViewController.h"

          @interface ViewController ()

           @end

           @implementation ViewController

      - (void)viewDidLoad {
      [super viewDidLoad];
NSString *docsDir;
NSArray *dirPaths;

dirPaths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);


docsDir=dirPaths[0];

_myDatabase=[[NSString alloc]initWithString:[docsDir stringByAppendingString:@"marks.db"]];
NSLog(@"My Data base %@",_myDatabase);

NSFileManager *fileMgr=[NSFileManager defaultManager];
if ([fileMgr fileExistsAtPath:_myDatabase]==NO)
{
    const char *dbpath=[_myDatabase UTF8String];

    if (sqlite3_open(dbpath, &_marksDB)==SQLITE_OK)
    {
        char *errMsg;


     const char *sql_stmt="CREATE TABLE IF NOT EXISTS MARKS(ID INTEGER     PRIMARY KEY AUTOINCREMENT ,FIRST NAME TEXT,LAST NAME TEXT,STATE TEXT,MOBILE INTEGER  )";

        if (sqlite3_exec(_marksDB, sql_stmt, NULL, NULL, &errMsg)!=SQLITE_OK)
        {
          _label.text=@"Failed to create Table";
        }
        sqlite3_close(_marksDB);
    }
    else
    {
         _label.text=@"Failed to Create/Open Database";
    }
}

}

        - (IBAction)saveButton:(id)sender {
        sqlite3_stmt *statement;
const char *dbpath=[_myDatabase UTF8String];
if (sqlite3_open(dbpath, &_marksDB)==SQLITE_OK)
{
    NSString *insertSQL=[NSString stringWithFormat:@"INSERT INTO MARKS(firstname,lastname,state,mobile )VALUES(\"%@\",\"%@\",\"%@\",\"%@\")",_firstName.text,_lastName.text,_state.text,_mobileNum.text ];
    const char *insert_stmt=[insertSQL UTF8String];

    sqlite3_prepare_v2(_marksDB, insert_stmt, -1, &statement, NULL);
    if (sqlite3_step(statement)==SQLITE_DONE)
    {
       _label.text=@"Contact Added";
        _firstName.text=@"";
       _lastName.text=@"";
       _state.text=@"";
       _mobileNum.text=@"";

    }
    else
    {
        _label.text=@"Failed to Add Contact";
    }
    sqlite3_finalize(statement);
    sqlite3_close(_marksDB);

}

}

      - (IBAction)featchButton:(id)sender {
         const char *dbpath=[_myDatabase UTF8String];
        sqlite3_stmt *statement;
           if (sqlite3_open(dbpath, &_marksDB)==SQLITE_OK)

{

    NSString *query=[NSString stringWithFormat:@"SELECT firstname,lastname,state,mobile,  FROM MARKS WHERE firstname=\"%@\"",_firstName.text];
    const char *query_stmt=[query UTF8String];
    if (sqlite3_prepare_v2(_marksDB, query_stmt, -1, &statement, NULL)==SQLITE_OK)
    {
        if (sqlite3_step(statement)==SQLITE_ROW)
        {
            NSString *first=[[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)];
            _firstName.text=first;

            NSString *lastName=[[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 1)];
           _lastName.text=lastName;

            NSString *state=[[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 2)];
            _state.text=state;
            NSString *mobile=[[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 3)];
            _mobileNum.text=mobile;


           _label.text=@"Match Found";





        }
        else
        {
           _label.text=@"Not Matched";
            _lastName.text=@"";
            _state.text=@"";
            _mobileNum.text=@"";
        }
        sqlite3_finalize(statement);
    }
    sqlite3_close(_marksDB);
}


 }
  @end