Use and Access Existing SQLite Database on iOS - ios

I have a fully populated database in SQLite that I'd like to use in my new app. It's rather large, so I'd like to avoid changing it to another format if possible. How can I use this database in such a way that it ships with my app?
EDIT: If I just drop the file into my Supported Files directory, for example, how can I access it? How do I reference it?

SQLite database interaction can be made simple and clean by using FMDB Framework. FMDB is an Objective-C wrapper for the SQLite C interface.
Reference worth reading:
FMDB Framework Docs
Sample Project With Storyboard
Initial Setup
Add the SQLite DB like any other file in your application's bundle then copy the database to documents directory using the following code then use the database from the documents directory
First download the FMDB framework
Extract the framework now copy all the file from src/fmdb folder (not the src/sample or src/extra folders).
Click your project in the left column of Xcode.
Click the main target in the middle column.
Click the “Build Phases” tab.
Expand the arrow next to “Link Binary With Libraries”.
Click the “+” button.
Search for libsqlite3.0.dylib and double click it.
Copying your existing database into app's document in didFinishLaunchingWithOptions: and maintain the database path through out the application.
In your AppDelegate add the following code.
AppDelegate.m
#import "AppDelegate.h"
#implementation AppDelegate
// Application Start
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Function called to create a copy of the database if needed.
[self createCopyOfDatabaseIfNeeded];
return YES;
}
#pragma mark - Defined Functions
// Function to Create a writable copy of the bundled default database in the application Documents directory.
- (void)createCopyOfDatabaseIfNeeded {
// First, test for existence.
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
// Database filename can have extension db/sqlite.
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *appDBPath = [documentsDirectory stringByAppendingPathComponent:#"database-name.sqlite"];
success = [fileManager fileExistsAtPath:appDBPath];
if (success) {
return;
}
// The writable database does not exist, so copy the default to the appropriate location.
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"database-name.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:appDBPath error:&error];
NSAssert(success, #"Failed to create writable database file with message '%#'.", [error localizedDescription]);
}
YourViewController.m
Select Query
#import "FMDatabase.h"
- (void)getAllData {
// Getting the database path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"database-name.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:dbPath];
[database open];
NSString *sqlSelectQuery = #"SELECT * FROM tablename";
// Query result
FMResultSet *resultsWithNameLocation = [database executeQuery:sqlSelectQuery];
while([resultsWithNameLocation next]) {
NSString *strID = [NSString stringWithFormat:#"%d",[resultsWithNameLocation intForColumn:#"ID"]];
NSString *strName = [NSString stringWithFormat:#"%#",[resultsWithNameLocation stringForColumn:#"Name"]];
NSString *strLoc = [NSString stringWithFormat:#"%#",[resultsWithNameLocation stringForColumn:#"Location"]];
// loading your data into the array, dictionaries.
NSLog(#"ID = %d, Name = %#, Location = %#",strID, strName, strLoc);
}
[database close];
}
Insert Query
#import "FMDatabase.h"
- (void)insertData {
// Getting the database path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"database-name.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:dbPath];
[database open];
NSString *insertQuery = [NSString stringWithFormat:#"INSERT INTO user VALUES ('%#', %d)", #"Jobin Kurian", 25];
[database executeUpdate:insertQuery];
[database close];
}
Update Query
- (void)updateDate {
// Getting the database path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"fmdb-sample.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:dbPath];
[database open];
NSString *insertQuery = [NSString stringWithFormat:#"UPDATE users SET age = '%#' WHERE username = '%#'", #"23", #"colin" ];
[database executeUpdate:insertQuery];
[database close];
}
Delete Query
#import "FMDatabase.h"
- (void)deleteData {
// Getting the database path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"database-name.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:dbPath];
[database open];
NSString *deleteQuery = #"DELETE FROM user WHERE age = 25";
[database executeUpdate:deleteQuery];
[database close];
}
Addition Functionality
Getting the row count
Make sure to include the FMDatabaseAdditions.h file to use intForQuery:.
#import "FMDatabase.h"
#import "FMDatabaseAdditions.h"
- (void)gettingRowCount {
// Getting the database path.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"database-name.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:dbPath];
[database open];
NSUInteger count = [database intForQuery:#"SELECT COUNT(field_name) FROM table_name"];
[database close];
}

Add the Sqlite DB like any other file in your application bundle
Copy it to documents directory via code and use it .The purpose of this is that updating content in sqlite is possible in Documents directory only
-(void) checkAndCreateDatabase
{
// Check if the SQL database has already been saved to the users phone, if not then copy it over
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];
}
- (id)init {
if ((self = [super init]))
{
_databaseName = DB_NAME;
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
_databasePath = [documentsDir stringByAppendingPathComponent:_databaseName];
if (sqlite3_open([[self dbPath] UTF8String], &_database) != SQLITE_OK)
{
[[[UIAlertView alloc]initWithTitle:#"Missing"
message:#"Database file not found"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil, nil]show];
}
}
return self;
}

This following methods will help you to handle database
Method for copy database in document directory if not exist
-(void)copyDatabase
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *insPath = [NSString stringWithFormat:#"Instamontage.sqlite"];
destPath = [documentsDirectory stringByAppendingPathComponent:insPath];
NSString *srcPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:insPath];
// NSLog(#"\n src %# \n dest %#", srcPath, destPath);
if (![[NSFileManager defaultManager] fileExistsAtPath:destPath])
{
NSError *error;
NSLog(#"not exist");
[[NSFileManager defaultManager] copyItemAtPath:srcPath toPath:destPath error:&error];
}
else
{
NSLog(#"exist");
}
}
Method for insert/deleting/updating table
-(BOOL)dataManipulation: (NSString *)query
{
BOOL result=NO;
if (sqlite3_open([destPath UTF8String], &connectDatabase)==SQLITE_OK)
{
sqlite3_stmt *stmt;
if (sqlite3_prepare_v2(connectDatabase, [query UTF8String], -1, &stmt, NULL)==SQLITE_OK)
{
sqlite3_step(stmt);
result=YES;
}
sqlite3_finalize(stmt);
}
sqlite3_close(connectDatabase);
return result;
}
Method for getting rows from table
-(NSMutableArray *)getData: (NSString *)query
{
NSMutableArray *arrData=[[NSMutableArray alloc]init];
if (sqlite3_open([destPath UTF8String],&connectDatabase)==SQLITE_OK)
{
sqlite3_stmt *stmt;
const char *query_stmt = [query UTF8String];
if (sqlite3_prepare_v2(connectDatabase,query_stmt, -1, &stmt, NULL)==SQLITE_OK)
{
while (sqlite3_step(stmt)==SQLITE_ROW)
{
NSMutableDictionary *dictResult=[[NSMutableDictionary alloc] init];
for (int i=0;i<sqlite3_column_count(stmt);i++)
{
NSString *str;
if (sqlite3_column_text(stmt,i)!=NULL)
{
str = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt,i)];
}
else
{
str=#"";
}
[dictResult setValue:str forKey:[NSString stringWithUTF8String:(char *)sqlite3_column_name(stmt,i)]];
}
[arrData addObject:dictResult];
}
sqlite3_finalize(stmt);
}
sqlite3_close(connectDatabase);
}
return arrData;
}
Above methods in swift will written as below
Method for copy database in document directory if not exist
func copyDatabaseToDocumentDirectory() {
let directoryList = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
var documentDirectory = directoryList.first
documentDirectory?.append("/DatabasePract1.sqlite")
print(documentDirectory!)
if !FileManager.default.fileExists(atPath: documentDirectory!) {
let databaseBundlePath = Bundle.main.path(forResource: "DatabasePract1", ofType: "sqlite")
do {
try FileManager.default.copyItem(atPath: databaseBundlePath!, toPath: documentDirectory!)
self.databasePath = documentDirectory
} catch {
print("Unable to copy database.")
}
} else {
print("database exist")
self.databasePath = documentDirectory
}
}
Method for insert/deleting/updating table
func dataManipulation(query: String) -> Bool {
var database: OpaquePointer?
var result = false
if (sqlite3_open(databasePath, &database) == SQLITE_OK) {
var queryStatement: OpaquePointer?
if (sqlite3_prepare_v2(database, query, -1, &queryStatement, nil) == SQLITE_OK) {
sqlite3_step(queryStatement)
result = true
} else {
let errmsg = String(cString: sqlite3_errmsg(database)!)
print("error preparing insert: \(errmsg)")
}
sqlite3_finalize(queryStatement)
}
sqlite3_close(database)
return result
}
Method for getting rows from table
func fetchData(_ query: String) -> [[String:Any]] {
var database: OpaquePointer?
var arrData: [[String:Any]] = []
if (sqlite3_open(databasePath, &database) == SQLITE_OK) {
var stmt:OpaquePointer?
if sqlite3_prepare(database, query, -1, &stmt, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(database)!)
print("error preparing insert: \(errmsg)")
return arrData
}
while(sqlite3_step(stmt) == SQLITE_ROW) {
var dictData: [String: Any] = [:]
for i in 0..<sqlite3_column_count(stmt) {
var strValue = ""
if (sqlite3_column_text(stmt, i) != nil) {
strValue = String(cString: sqlite3_column_text(stmt, i))
}
let keyName = String(cString: sqlite3_column_name(stmt, i), encoding: .utf8)
dictData[keyName!] = strValue
}
arrData.append(dictData)
}
sqlite3_close(database)
}
return arrData
}

Using swift, singleton class and FMDB. you can use below code to achieve it very easily.
Download example
import Foundation
class LocalDatabase: NSObject {
//sharedInstance
static let sharedInstance = LocalDatabase()
func methodToCreateDatabase() -> NSURL? {
let fileManager = NSFileManager.defaultManager()
let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
if let documentDirectory:NSURL = urls.first { // No use of as? NSURL because let urls returns array of NSURL
// exclude cloud backup
do {
try documentDirectory.setResourceValue(true, forKey: NSURLIsExcludedFromBackupKey)
} catch _{
print("Failed to exclude backup")
}
// This is where the database should be in the documents directory
let finalDatabaseURL = documentDirectory.URLByAppendingPathComponent("contact.db")
if finalDatabaseURL.checkResourceIsReachableAndReturnError(nil) {
// The file already exists, so just return the URL
return finalDatabaseURL
} else {
// Copy the initial file from the application bundle to the documents directory
if let bundleURL = NSBundle.mainBundle().URLForResource("contact", withExtension: "db") {
do {
try fileManager.copyItemAtURL(bundleURL, toURL: finalDatabaseURL)
} catch _ {
print("Couldn't copy file to final location!")
}
} else {
print("Couldn't find initial database in the bundle!")
}
}
} else {
print("Couldn't get documents directory!")
}
return nil
}
func methodToInsertUpdateDeleteData(strQuery : String) -> Bool
{
// print("%#",String(methodToCreateDatabase()!.absoluteString))
let contactDB = FMDatabase(path: String(methodToCreateDatabase()!.absoluteString) )
if contactDB.open() {
let insertSQL = strQuery
let result = contactDB.executeUpdate(insertSQL,
withArgumentsInArray: nil)
if !result {
print("Failed to add contact")
print("Error: \(contactDB.lastErrorMessage())")
return false
} else {
print("Contact Added")
return true
}
} else {
print("Error: \(contactDB.lastErrorMessage())")
return false
}
}
func methodToSelectData(strQuery : String) -> NSMutableArray
{
let arryToReturn : NSMutableArray = []
print("%#",String(methodToCreateDatabase()!.absoluteString))
let contactDB = FMDatabase(path: String(methodToCreateDatabase()!.absoluteString) )
if contactDB.open() {
let querySQL = strQuery
let results:FMResultSet? = contactDB.executeQuery(querySQL,
withArgumentsInArray: nil)
while results?.next() == true
{
arryToReturn.addObject(results!.resultDictionary())
}
// NSLog("%#", arryToReturn)
if arryToReturn.count == 0
{
print("Record Not Found")
}
else
{
print("Record Found")
}
contactDB.close()
} else {
print("Error: \(contactDB.lastErrorMessage())")
}
return arryToReturn
}
}

To copy .sqlite file in directory...
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
// Database filename can have extension db/sqlite.
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *databasePath = [documentsDirectory stringByAppendingPathComponent:#"MapView.sqlite"];
success = [fileManager fileExistsAtPath:databasePath];
// if (success){
// return;
// }
// The writable database does not exist, so copy the default to the appropriate location.
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"MapView.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:databasePath error:&error];
if (!success) {
//NSAssert1(0, #"Failed to create writable database file with message '%#'.", [error localizedDescription]);
}
else
{
NSLog(#"Database created successfully");
}
To select Data From Database...
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &mapDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat: #"SELECT * FROM maplatlong"];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(mapDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
while(sqlite3_step(statement) == SQLITE_ROW)
{
NSString *cityN = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
NSString *lat = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
NSString *longi = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 2)];
[cityName addObject:cityN];
[latitude addObject:lat];
[longitude addObject:longi];
}
sqlite3_finalize(statement);
}
sqlite3_close(mapDB);
}

Related

no such table: tablename in sqlite even after initialization

i am new to ios dev and i am having the following problem:
i initialized the tables i needed, and when i try to execute a query to any of the tables i get the "no such table" error, here is the steps and code:
-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Function called to create a copy of the database if needed.
[[SQLiteUtilities sharedSQLiteManager] initializationDatabase];
return YES;
}
and here is the implementation:
-(void)initializationDatabase {
NSString *path = [self databaseFilePath];
BOOL isExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
if (isExists) return;
FMDatabase *db = [FMDatabase databaseWithPath:path];
if ([db open] == NO) {
return;
}
NSString *sql =
#"CREATE TABLE albums("
"albumid INTEGER PRIMARY KEY AUTOINCREMENT,"
"directory CHAR(20) NOT NULL,"
"albumname CHAR(32) NOT NULL,"
"count INT NOT NULL,"
"orderid INT NOT NULL"
");"
"CREATE TABLE photos("
"photoid INTEGER PRIMARY KEY AUTOINCREMENT,"
"albumid INTEGER NOT NULL DEFAULT 0,"
"filename CHAR(50) NOT NULL DEFAULT \"\","
"originalname CHAR(50) DEFAULT \"\","
"addtime INTEGER NOT NULL DEFAULT 0,"
"createtime INTEGER NOT NULL DEFAULT 0,"
"filesize INTEGER NOT NULL DEFAULT 0"
");";
//[db executeQuery:sql1];
[db executeQuery:sql];
[db close];
}
and when i try to add anything as follows i get the "no such table:albums" error:
- (AlbumsUtilities *)createAlbumWithName:(NSString *)name {
FMDatabase *db = [FMDatabase databaseWithPath:[self databaseFilePath]];
if (![db open]) return nil;
NSString *directory = createRandomAlbumDirectory();
int maxid = 0;
BOOL success = [db executeUpdate:#"INSERT INTO albums(directory,albumname,count,orderid) VALUES(?,?,0,?)", directory,name,#(maxid)];
AlbumsUtilities *album = nil;
if (success) {
....(not getting here of course)
}
[db close];
return album;
}
any help would be appreciated, thanks.
Try this two function for initialize db .
ADD Blank File .sqlite extension
- (void)createCopyOfDatabaseIfNeeded {
// First, test for existence.
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSLog(#"%#",[self getDBPath]);
success = [fileManager fileExistsAtPath:[self getDBPath]];
if (success){
return;
}
// The writable database does not exist, so copy the default to the appropriate location.
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"db.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:[self getDBPath] error:&error];
if (!success) {
NSAssert1(0, #"Failed to create writable database file with message '%#'.", [error localizedDescription]);
}
}
-(NSString *)getDBPath{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *dbPath = [docsPath stringByAppendingPathComponent:#"db.sqlite"];
return dbPath;
}
After Initialize create table
-(void)createTable{
FMDatabase *database = [FMDatabase databaseWithPath:[self getDBPath]];
[database open];
[database executeUpdate:"your query"];
[database close];
}
Calling
-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Function called to create a copy of the database if needed.
[[SQLiteUtilities sharedSQLiteManager] createCopyOfDatabaseIfNeeded];
[[SQLiteUtilities sharedSQLiteManager] createTable];
}
#Try this:
Bool isSuccess = YES;
if (sqlite3_open(path, &db) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt =
"CREATE TABLE IF NOT EXISTS contactTable (albumid integer primary key autoincrement ,directory CHAR(20) NOT NULL, albumname CHAR(32) NOT NULL, albumname CHAR(32) NOT NULL, count INT NOT NULL, orderid INT NOT NULL);";
if (sqlite3_exec(db, sql_stmt, NULL, NULL, &errMsg)
!= SQLITE_OK)
{
sqlite3_close(db);
isSuccess = NO;
}
sqlite3_close(db);
return isSuccess;
}
else {
sqlite3_close(db);
isSuccess = NO;
}
}
sqlite3_close(db);
NSLog(#"Albums Table Created");
return isSuccess;

cannot create database table and insert in iOS sqlite3

I am new in iOS development. I am trying to do a simple todo list app. I am using xocde 8 and objective-C language . I tried several tutorial but could not create the database table. Here is my code.
-(void)createOrOpenDB{
printf("createOrOpenDB: into this function \n");
NSArray *docsDir = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *dirPaths = [docsDir objectAtIndex:0];
dbPathString = [[NSString alloc] initWithString: [dirPaths stringByAppendingPathComponent:#"person.db"]];
NSFileManager *fileManager = [NSFileManager defaultManager];
char *err;
printf("createOrOpenDB: into this function before if statement \n");
if(![fileManager fileExistsAtPath:dbPathString]){
const char *dbPath = [dbPathString UTF8String];
printf("createOrOpenDB: into this functions 1st if statement \n");
//create db here
if(sqlite3_open(dbPath, &personDB) ==SQLITE_OK){
const char *sql_stnt = "CREATE TABLE IF NOT EXISTS PERSONS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, AGE INTEGER)";
if(sqlite3_exec(personDB, sql_stnt, NULL, NULL, &err) !=SQLITE_OK){
printf("Failed to create table\n");
}
sqlite3_close(personDB);
printf("createOrOpenDB: database table created\n");
}
}
}
when i press the add button , its not giving me any error. but its not adding any data. NSLog in not working in xcode 8 . so i did printf instead . and my code breaks before the if statement . can anybody tell me what i am doing wrong?
do like this,
+(DBManager*)getSharedInstance{
if (!sharedInstance) {
sharedInstance = [[super allocWithZone:NULL]init];
[sharedInstance createDB];
}
return sharedInstance;
}
-(BOOL)createDB{
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];
// Build the path to the database file
databasePath = [[NSString alloc] initWithString:
[docsDir stringByAppendingPathComponent: #"student.db"]];
BOOL isSuccess = YES;
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: databasePath ] == YES)
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt = "create table if not exists studentsDetail (regno integer primary key, name text, department text, year text)";
if (sqlite3_exec(database, sql_stmt, NULL, NULL, &errMsg)
!= SQLITE_OK)
{
isSuccess = NO;
NSLog(#"Failed to create table");
}
else
{
NSLog(#"Table Created Successfully");
}
sqlite3_close(database);
return isSuccess;
}
else {
isSuccess = NO;
NSLog(#"Failed to open/create database");
}
sqlite3_finalize(statement);
}
return isSuccess;
// NSLog(#"database %#", isSuccess);
}
For saving the data in this table,
- (BOOL) saveData:(NSString*)registerNumber name:(NSString*)name
department:(NSString*)department year:(NSString*)year;
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
NSString *insertSQL = [NSString stringWithFormat:#"insert into studentsDetail (regno,name, department, year) values (\"%ld\",\"%#\", \"%#\", \"%#\")",(long)[registerNumber integerValue], name, department, year];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(database, insert_stmt,-1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
return YES;
}
else {
return NO;
}
sqlite3_reset(statement);
}
return NO;
}
It will create table every time when table does not exist.
Hope t will help you.

Taking too much time to retrieve rows from SQLite

I am new to iOS. I am trying to implement a SQLite database.
My problem is that when I go to fetch data from database, it takes a lot of time even though there are only 50 records inside the tables.
I did make a separate method for fetching data because many times I need to retrieve data for different tables.
My method:
-(NSArray*)fetch_data:(NSString *)table_name fields_arr:(NSMutableArray *)fields_arr{
NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = dirPaths[0];
databasePath = [[NSString alloc] initWithString:[docsDir stringByAppendingPathComponent: #"test.db"]];
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK)
{
sqlite3_stmt *SelectStatement;
NSMutableDictionary *record_dict;
NSString *SelectQry=#"select ";
NSString *lastField = [fields_arr lastObject];
for (int i =0; i<[fields_arr count]; i++) {
if (fields_arr[i] == lastField) {
SelectQry = [SelectQry stringByAppendingString:[NSString stringWithFormat:#"%# ",fields_arr[i]]];
} else {
SelectQry = [SelectQry stringByAppendingString:[NSString stringWithFormat:#"%#,",fields_arr[i]]];
}
}
SelectQry = [SelectQry stringByAppendingString:[NSString stringWithFormat:#"from %#",table_name]];
const char *query_stmt = [SelectQry UTF8String];
NSMutableArray *resultArray = [[NSMutableArray alloc]init];
if (sqlite3_prepare_v2(database,
query_stmt, -1, &SelectStatement, NULL) == SQLITE_OK)
{
while(sqlite3_step(SelectStatement) == SQLITE_ROW)
{
record_dict=[[NSMutableDictionary alloc]init];
for (int i = 0; i<[fields_arr count]; i++) {
NSString *field_value = [[NSString alloc]init];
field_value = [[NSString alloc] initWithUTF8String:
(const char *) sqlite3_column_text(SelectStatement, i)];
[record_dict setValue:field_value forKey:fields_arr[i]];
}
[resultArray addObject:record_dict];
}
return resultArray;
//sqlite3_reset(statement);
sqlite3_finalize(SelectStatement);
}
else{
sqlite3_finalize(SelectStatement);
return nil;
}
}
In your code you are opening database connection for each time method is called for fetching data. This is not appropriate way. You must establish connection only once and use it.
+(sqlite3 *)openDatabase{
if (database == NULL) {
NSString* str_path=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *path = [str_path stringByAppendingPathComponent:strDatabaseName];
if (sqlite3_open([path UTF8String], &database) == SQLITE_OK) {
NSLog(#"Database Successfully Opened");
}
else {
NSLog(#"Error in opening database");
database = NULL;
}
}
return database;}
You can call this on app launch from app delegate and define this method in a class where you are defining other DB methods. I hope it will reduce some overhead and will reduce some time too.

Error with sqlite statement

i got a sqlite database but something is wrong with my statement this is my method to open the database and to retrieve some data i need:
- (void)createEditableCopyOfDatabaseIfNeeded
{
// First, test for existence.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:#"monsterDB.DB"];
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
success = [fileManager fileExistsAtPath:writableDBPath];
if (success)
{
// TODO: auch aktuelle version ? -> server check
return;
}
// TODO: The writable database does not exist, so copy the default from server to the appropriate location.
}
- (sqlite3 *)getDBConnection
{
[self createEditableCopyOfDatabaseIfNeeded];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"monsterDB.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;
}
- (DEMonster *)getEventByType:(NSString *)type
{
DEMonster *result = nil;
sqlite3 *connection = [self getDBConnection];
NSString *textString = [NSString stringWithFormat:#"SELECT * FROM monsters WHERE type = '%#' ORDER BY RANDOM() LIMIT 1;", #"city"]; // TODO: Hier type nehmen für testzwecke nur city
const char *text = [textString UTF8String];
sqlite3_stmt *select_statement;
if (sqlite3_prepare_v2(connection, text, -1, &select_statement, NULL) != SQLITE_OK)
{
// error
NSLog(#"Error");
sqlite3_close(connection);
return result;
}
if (sqlite3_step(select_statement) == SQLITE_ROW)
{
result = [[DEMonster alloc] init];
result.name = [[NSString alloc] initWithUTF8String:(char const *)sqlite3_column_text(select_statement, 1)];
result.attacks = [[NSMutableArray alloc] initWithObjects:[[NSString alloc] initWithUTF8String:(char const *)sqlite3_column_text(select_statement, 2)], [[NSString alloc] initWithUTF8String:(char const *)sqlite3_column_text(select_statement, 3)], nil];
result.defenses = [[NSMutableArray alloc] initWithObjects:[[NSString alloc] initWithUTF8String:(char const *)sqlite3_column_text(select_statement, 4)], [[NSString alloc] initWithUTF8String:(char const *)sqlite3_column_text(select_statement, 5)], nil];
int length = sqlite3_column_bytes(select_statement, 6);
NSData *imageData = [NSData dataWithBytes:sqlite3_column_blob(select_statement, 6) length:length];
result.monsterIcon = [UIImage imageWithData:imageData];
result.attackValue = sqlite3_column_double(select_statement, 12);
result.defenseValue = sqlite3_column_double(select_statement, 13);
result.attackValues = [[NSMutableArray alloc] initWithObjects:[NSNumber numberWithDouble:sqlite3_column_double(select_statement, 8)], [NSNumber numberWithDouble:sqlite3_column_double(select_statement, 9)], nil];
result.defenseValues = [[NSMutableArray alloc] initWithObjects:[NSNumber numberWithDouble:sqlite3_column_double(select_statement, 10)], [NSNumber numberWithDouble:sqlite3_column_double(select_statement, 11)], nil];
}
sqlite3_finalize(select_statement);
sqlite3_close(connection);
return (result);
}
Basically the problem is in the "getEventByType" method. Somehow i always get the "Error" NSLog, because my statement does not return "SQLITE_OK".
The output looks like this:
2014-04-15 22:24:15.805 MonsterSafari[3701:60b] Database Successfully Opened :)
2014-04-15 22:24:15.806 MonsterSafari[3701:60b] Error
As you can see the database looks to be opened successfully, but somehow the statement looks to be wrong. When i run the exact same statement in my sqlbrowser (some app i use to browse the sqlite database) the query works just fine. Any idea what could possibly be wrong ?
Thanks in advance

Creating a singleton DB helper class

I am trying to write a Master-Detail application that gets it's data from a sqlite database. As part of this I'm trying to create a helper class that creates a singleton instance of my database. All I want it to do is initialise the database so I can then reference this from the different views of the application.
I followed a tutorial that does this here: http://www.raywenderlich.com/913/sqlite-101-for-iphone-developers-making-our-app
I got the tutorial to work however now I am trying to modify it to fit my application and I can't seem to get it working. I have no errors or warnings but when I run the app on the emulator none of the debug text I have put in executes. So it looks to me like my init function is not executing. I just can't figure out why.
Can anyone spot my problem in the code below?
LoyaltyProgramDatabase.h
#import <Foundation/Foundation.h>
#import <sqlite3.h>
#interface LoyaltyProgramDatabase : NSObject {
sqlite3 *_loyaltyProgDB;
}
#property (strong, nonatomic) NSString *databasePath; //Path file of our database
#property (nonatomic) sqlite3 *loyaltyProgDB; //Reference to the database
+ (LoyaltyProgramDatabase*)loyaltyProgDB;
#end
LoyaltyProgramDatabase.m
#import "LoyaltyProgramDatabase.h"
#implementation LoyaltyProgramDatabase
static LoyaltyProgramDatabase *_loyaltyProgDB;
//Create a singleton instance of loyaltyProgDB
+ (LoyaltyProgramDatabase*)loyaltyProgDB {
if (_loyaltyProgDB == nil) {
_loyaltyProgDB = [[LoyaltyProgramDatabase alloc] init];
}
return _loyaltyProgDB;
}
- (id)init {
NSLog(#"Inside init function");
if ((self = [super init])) {
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];
// Build the path to the database file
_databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:#"loyaltyProg.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_loyaltyProgDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt = "CREATE TABLE IF NOT EXISTS scoreCard (ID INTEGER PRIMARY KEY AUTOINCREMENT, campaignID INTEGER, merchantName TEXT)";
if (sqlite3_exec(_loyaltyProgDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
//_status.text = #"Failed to create table";
NSLog(#"Failed to create table");
}
sqlite3_close(_loyaltyProgDB);
} else {
//_status.text = #"Failed to open/create database";
NSLog(#"Failed to open/create database");
}
}
}
return self;
}
- (void)dealloc {
sqlite3_close(_loyaltyProgDB);
}
#end
Try this:
+ (id)allocWithZone:(NSZone *)zone
{
return [self loyaltyProgDB];
}
+ (LoyaltyProgramDatabase*)loyaltyProgDB
{
static BNRImageStore *loyaltyProgDB = nil;
if (!loyaltyProgDB) {
// Create the singleton
loyaltyProgDB = [[super allocWithZone:NULL] init];
}
return loyaltyProgDB;
}
- (id)init {
self = [super init];
if (self) {
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];
// Build the path to the database file
_databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:#"loyaltyProg.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_loyaltyProgDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt = "CREATE TABLE IF NOT EXISTS scoreCard (ID INTEGER PRIMARY KEY AUTOINCREMENT, campaignID INTEGER, merchantName TEXT)";
if (sqlite3_exec(_loyaltyProgDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
//_status.text = #"Failed to create table";
NSLog(#"Failed to create table");
}
sqlite3_close(_loyaltyProgDB);
} else {
//_status.text = #"Failed to open/create database";
NSLog(#"Failed to open/create database");
}
}
}
return self;
}
If you have not written a line of code that says [[LoyaltyProgramDatabase alloc] init] or [LoyaltyProgramDatabase loyaltyProgDB], then your init function is never getting called.
The init is not automatically called when you start the app. The only time any init function is called automatically is if you have a UI element in a nib/xib/storyboard file, and the app creates the element utilizing various initialization functions, but never your own init function. But for something like what you have written, to initialize the database object, you need to call the init function yourself.
In your app delegate, under the didFinishLaunching function, put this line:
[LoyaltyProgramDatabase loyaltyProgDB];
This isn't a really up-to-date singleton pattern by the way. This is actually a lazy loader function. If you want a more secure singleton, use this code.
+(id)sharedInstance {
static dispatch_once_t pred = 0;
__strong static id _sharedObject = nil;
dispatch_once(&pred, ^{
_sharedObject = [[self alloc] init];
});
return _sharedObject;
}
This will make sure the database is only ever initialized once and it is thread safe. To create/use the singleton, the code would change from the above to
[LoyaltyProgramDatabase sharedInstance]

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