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//  

//    

//  Persistence3  

//  

//  Created by liu lavy on 11-10-3.  

//  Copyright 2011 __MyCompanyName__. All rights reserved.  

//  

  

#import ""  

#import <>  

  

@implementation Persistence3ViewController  

@synthesize field1;  

@synthesize field2;  

@synthesize field3;  

@synthesize field4;  

  

//The complete path to the data file  

- (NSString *)dataFilePath {  

    //Retrieve the Documents directory path. The second parameter means limiting search to our application sandbox  

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  

    // Each application has only one Documents directory  

    NSString *documentsDirectory = [paths objectAtIndex:0];  

    //Create a file name  

    return [documentsDirectory stringByAppendingPathComponent:kFilename];  

}  

  

// When the application exits, save the data to the attribute list file  

- (void)applicationWillResignActive:(NSNotification *)notification {  

    sqlite3 *database;  

    if(sqlite3_open([[self dataFilePath] UTF8String], &database) != SQLITE_OK) {  

        sqlite3_close(database);  

        NSAssert(0, @"Failed to open database");  

    }  

      

    for(int i = 1; i <= 4; i++) {  

        NSString *fieldname = [[NSString alloc] initWithFormat:@"field%d", i];  

        UITextField *field = [self valueForKey:fieldname];  

        [fieldname release];  

          

        char *update = "INSERT OR REPLACE INTO FIELDS (ROW, FIELD_DATA) VALUES (?, ?);";  

        sqlite3_stmt *stmt;  

        //Compile the SQL statement into a structure (sqlite3_stmt) inside sqlite, similar to the PreparedStatement precompilation of java JDBC  

        if (sqlite3_prepare_v2(database, update, -1, &stmt, nil) == SQLITE_OK) {  

            //When binding parameter, the index of the parameter list starts from 1, and when taking out data, the index of the column starts from 0  

            sqlite3_bind_int(stmt, 1, i);  

            sqlite3_bind_text(stmt, 2, [ UTF8String], -1, NULL);  

        } else {  

            NSAssert(0, @"Error:Failed to prepare statemen");  

        }  

        //Execute SQL text to get the results  

        int result = sqlite3_step(stmt);  

        if(result != SQLITE_DONE) {  

            NSAssert1(0, @"Error updating table: %d", result);  

        }  

        //Release the memory occupied by stmt (allocated by sqlite3_prepare_v2())  

        sqlite3_finalize(stmt);  

    }  

    sqlite3_close(database);  

}  

  

/* 

 // The designated initializer. Override to perform setup that is required before the view is loaded. 

 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { 

 self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 

 if (self) { 

 // Custom initialization 

 } 

 return self; 

 } 

 */  

  

/* 

 // Implement loadView to create a view hierarchy programmatically, without using a nib. 

 - (void)loadView { 

 } 

 */  

  

  

  

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.  

- (void)viewDidLoad {  

    [super viewDidLoad];  

    NSString *filePath = [self dataFilePath];  

    //Check whether the data file exists  

    if([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {  

        //Open the database  

        sqlite3 *database;  

        if(sqlite3_open([filePath UTF8String], &database) != SQLITE_OK) {  

            sqlite3_close(database);  

            NSAssert(0, @"Failed to open database");  

        }  

          

        //Create a table  

        char *errorMsg;  

        NSString *createSQL =   

            @"CREATE TABLE IF NOT EXISTS FIELDS (ROW INTEGER PRIMARY KEY, FIELD_DATA TEXT);";  

        if(sqlite3_exec(database, [createSQL UTF8String], NULL, NULL, &errorMsg) != SQLITE_OK) {  

            sqlite3_close(database);  

            NSAssert(0, @"Error creating table: %s", errorMsg);  

        }  

  

        //Inquiry  

        NSString *query = @"SELECT ROW, FIELD_DATA FROM FIELDS ORDER BY ROW";  

        sqlite3_stmt *statement;  

        //Set nByte to speed up operation  

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

            while (sqlite3_step(statement) == SQLITE_ROW) {//Return to each row  

                int row = sqlite3_column_int(statement, 0);  

                char *rowData = (char *)sqlite3_column_text(statement, 1);  

                  

                NSString *fieldName = [[NSString alloc] initWithFormat:@"field%d", row];  

                NSString *fieldValue = [[NSString alloc] initWithUTF8String:rowData];  

                  

                UITextField *field = [self valueForKey:fieldName];  

                 = fieldValue;  

                  

                [fieldName release];  

                [fieldValue release];  

            }  

            //Release the memory occupied by the statement (allocated by sqlite3_prepare())  

            sqlite3_finalize(statement);  

        }  

        sqlite3_close(database);  

    }  

      

      

    UIApplication *app = [UIApplication sharedApplication];  

    [[NSNotificationCenter defaultCenter] addObserver:self  

                                             selector:@selector(applicationWillResignActive:)  

                                                 name:UIApplicationWillResignActiveNotification  

                                               object:app];  

    [super viewDidLoad];  

}  

  

  

/* 

 // Override to allow orientations other than the default portrait orientation. 

 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { 

 // Return YES for supported orientations 

 return (interfaceOrientation == UIInterfaceOrientationPortrait); 

 } 

 */  

  

- (void)didReceiveMemoryWarning {  

    // Releases the view if it doesn't have a superview.  

    [super didReceiveMemoryWarning];  

      

    // Release any cached data, images, etc that aren't in use.  

}  

  

- (void)viewDidUnload {  

    self.field1 = nil;  

    self.field2 = nil;  

    self.field3 = nil;  

    self.field4 = nil;  

    [super viewDidUnload];  

}  

  

  

- (void)dealloc {  

    [field1 release];  

    [field2 release];  

    [field3 release];  

    [field4 release];  

    [super dealloc];  

}  

  

@end