-(void)initializeTableData
{
sqlite3 *db=[DatabaseTestAppDelegate getNewDBConnection];
sqlite3_stmt *statement=nil;
const char *sql="select * from WhereTo";
if (sqlite3_prepare_v2(db, sql, -1, &statement, NULL)!=SQLITE_OK)
NSAssert1(0,#"error in preparing staement",sqlite3_errmsg(db));
else {
while(sqlite3_step(statement)==SQLITE_ROW)
[tableData addObject:[NSString stringWithFormat:#"%s",(char*)sqlite3_column_text(statement,1)]];
}
sqlite3_finalize(statement);
}
at sqlite3 *db=[DatabaseTestAppDelegate getNewDBConnection]; <--- it says, DatabaseTestAppDelegate may not respond to '+getNewDbConnection'
and here is my getNewDbConnection
+(sqlite3 *) getNewDBConnection{
sqlite3 *newDBconnection;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"Malacca-lah.sqlite"];
// Open the database. The database was prepared outside the application.
if (sqlite3_open([path UTF8String], &newDBconnection) == SQLITE_OK) {
NSLog(#"Database Successfully Opened :)");
}
else {
NSLog(#"Error in opening database :(");
}
return newDBconnection;
}
im new to XCode and also SQLite... been learning this for the past few weeks now, trying to get a hang on it... anyways, pls help me out with this problem. I understand the whole code but i dont understand why the inheritance has an issue.
Thanks in advance
If it says that a class may not respond to a selector, it means that it can not able to find the method declaration of the selector. Have you declared the method +(sqlite3 *)getNewDBConnection in DatabaseTestAppDelegate's header(".h") file?
Related
In my application i open the database many time in one loop and then again i open the database it will not execute if (sqlite3_open([[self getDBPath] UTF8String], &database) == SQLITE_OK) this statement so my application doesnt work....
-(NSString *)getDBPath
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
return [documentsDir stringByAppendingPathComponent:#"BasicGreetings.sqlite"];
}
-(void) fillimage:(NSInteger)imgno
{
testAppDelegate *appDelg = (testAppDelegate *)[[UIApplication sharedApplication]delegate];
sqlite3 *database= nil;
if (sqlite3_open([[self getDBPath] UTF8String], &database) == SQLITE_OK)
{
const char *sql = "select setflag from Tblsetflag where imgNo = ?";
sqlite3_stmt *selectStmt = nil;
if (sqlite3_prepare_v2(database, sql, -1, &selectStmt, NULL) == SQLITE_OK)
{
sqlite3_bind_int(selectStmt, 1,imgno);
while (sqlite3_step(selectStmt) == SQLITE_ROW)
{
appDelg.a = sqlite3_column_int(selectStmt, 0);
NSLog(#"%d",appDelg.a);
}
}
}
sqlite3_close(database);
}
Can you post the code to getDBPath, I suspect it can't find the file... check that value you return from that method (run in the simulator) and browse the simulator documents directory in Finder and verify the file exists.
Don't open and close your database on every pass through your -fillimage: method. You really should open it once at the start of your application (or when your application has become active from the background) and close it when your application exits or goes to the background.
You also never finalize your prepared statement, which may be leading to the sqlite3_close() failing. Again, you may want to create a prepared statement once, then reset it every time you run that method and finalize it before the SQLite database is closed.
How to use sqlite3_column_blob with NSData what parameter I need to pass
In my iPhone App I want to retrive image stored in NSData format in sqlite database in BLOB datatype
for retriving it
//select query
NSString *selectQuery = [NSString stringWithFormat:#"select image_column from tbl_image where id=1"];
NSArray *arraySelect = [database executeQuery:selectQuery];
//displaying image
NSData *imageData = [[arraySelect objectAtIndex:0] valueForKey:#"image_column"];
self.img3=[UIImage imageWithData:imageData];
imageView.image=img3;
from above code I am not able to display image
so please help and suggest
thanks
sqlite *database;
sqlite3_stmt *Stmt;
sqlite3_open([[self getDBPath] UTF8String],&database)
- (NSString *) getDBPath
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
return [documentsDir stringByAppendingPathComponent:#"XXX.sqlite"];
}
NSData*thumbnailData;
//Inserting Thumbnail Data
NSString *lSQL = [NSString stringWithFormat:#"insert into Table(Thumbnail1) values(?)"];
if(sqlite3_prepare_v2(database, [lSQL UTF8String], -1, &Stmt, NULL) == SQLITE_OK)
{
sqlite3_bind_blob(Stmt, 1,[thumbnailData bytes], [thumbnailData length], NULL);
sqlite3_step(Stmt);
sqlite3_reset(Stmt);
if(Stmt)
sqlite3_finalize(Stmt);
}
//Fetching Thumbnail Data
NSString *lSQL = [NSString stringWithFormat:#"select Thumbnail1 from table"];
if(sqlite3_prepare_v2(database, [lSQL UTF8String], -1, &Stmt, NULL) == SQLITE_OK)
{
while(sqlite3_step(Stmt) == SQLITE_ROW)
{
NSString *myColNameNSString = [NSString stringWithFormat:#"%s", sqlite3_column_name(Stmt)];
if ([myColNameNSString isEqualToString:#"Thumbnail1"])
{
thumbnailData = [[NSData alloc] initWithBytes:sqlite3_column_blob(Stmt) length:sqlite3_column_bytes(Stmt)];
}
}
}
Hey, I don't what are your project requirements. I would not use BLOB unless it's required to.
reason is you are storing image file into sqlite, everytime you have to use the file you have access the database, process the file and use. which will be fairly easy and simple in terms of number of threads you are running if you use images directly form the disk. give a thought about it. Good Luck
i have a database that is in the documents directorys of the
Application/iPhoneSimulator/3.2/Applications/etc/Documents
I have this code under my method
databaseName = #"database.sql";
NSArray *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory.NSUserDomainMask,YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
databasePath = [documentsDir stringByAppendingPathComponent:databaseName];
How do i do an insert with a variable/ array .
Something like
"INSERT INTO TABLE (COLUMN) VALUES ('%#'),[appDelegate.variable objectAtIndex:0];
I insist you to go through this question.
First of all copy the database from main bundle to your application's document dir.
You can follow below code to implement it.
NSString *databaseFile=[[NSBundle mainBundle] pathForResource:kDataBaseName ofType:kDataBaseExt];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
NSString *dbPath=[basePath stringByAppendingPathComponent:[NSString stringWithFormat:#"%#.%#",kDataBaseName,kDataBaseExt]];
NSFileManager *fm=[NSFileManager defaultManager];
if(![fm fileExistsAtPath:dbPath]){
[fm copyItemAtPath:databaseFile toPath:dbPath error:nil];
}
[fm release];
self.dataBasePath=dbPath;
I am supplying you directly my project code. Please add comment if any doubts.
I have added comments for the explanation.
// function with multiple arguments which is going to be used for inserting into table.
+(void)insertBuilding:(NSString*)BName streetNo:(NSInteger)streetNo streetName:(NSString*)streetName streetDir:(NSString*)streetDir muni:(NSString*)muni province:(NSString*)province bAccess:(NSString*)bAccess bType:(NSString*)bType amnity:(NSString*)amnity latitude:(NSString*)latitude longitude:(NSString*)longitude imageName:(NSString*)imageName {
// application delegate where I have saved my database path.
BuildingLocatorAppDelegate *x=(BuildingLocatorAppDelegate *)[[UIApplication sharedApplication]delegate];
sqlite3 *database; // database pointer
// verifying if database successfully opened from path or not.
// you must open database for executing insert query
// i have supplied database path in argument
// opened database address will be assigned to database pointer.
if(sqlite3_open([[x dataBasePath] UTF8String],&database) == SQLITE_OK) {
// creating a simple insert query string with arguments.
NSString *str=[NSString stringWithFormat:#"insert into buildingDtl(b_name,streetNo,streetName,streetDir,muni,province,b_access,b_type,aminity,latitude,longitude,b_image) values('%#',%i,'%#','%#','%#','%#','%#','%#','%#','%#','%#','%#')",BName,streetNo,streetName,streetDir,muni,province,bAccess,bType,amnity,latitude,longitude,imageName];
// converting query to UTF8string.
const char *sqlStmt=[str UTF8String];
sqlite3_stmt *cmp_sqlStmt;
// preparing for execution of statement.
if(sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL)==SQLITE_OK) {
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt, NULL);
((returnValue==SQLITE_OK) ? NSLog(#"Success") : NSLog(#"UnSuccess") );
// if NSLog -> unsuccess - that means - there is some problem with insert query.
sqlite3_step(cmp_sqlStmt);
}
sqlite3_finalize(cmp_sqlStmt);
}
sqlite3_close(database);
// please don't forget to close database.
}
+(NSString *)stringWithFormat:(NSString *)format parameters:...];
NSString sql = [NSString stringWithFormat:#"INSERT INTO table VALUES('%#')", #"Hello, world!"];
sqlite3_....
Use either prepared statements in combination with the bind_*() functions (e.g. bind_text()) or the mprintf() function to insert strings, see this question for details.
To get a raw C-string you can pass to these functions use -UTF8String or -cStringUsingEncoding: on a NSString.
I have the following function in my iPhone project which works great...unless the query returns nothing and then the app crashes. It is being a pain to debug with none of the breakpoints being activated at all!
I know this works as I pass in static stuff that is in the DB and it returns a value.
-(NSString *)getSomeText:(NSString *)toPass {
sqlite3 *database;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *databasePath = [documentsDirectory stringByAppendingPathComponent:#"sf.sqlite"];
int strLength = 0;
strLength = [toPass length];
if (strLength <3)
return #"Unknown";
NSString *MIDstr;
NSMutableString * toPass Copy = [NSMutableString stringWithString:toPass];
MIDstr = [toPassCopy substringWithRange:NSMakeRange(0, 3)];
// Open the database from the users filessytem
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
// Setup the SQL Statement and compile it for faster access
NSString *BaseSQL = [NSString stringWithFormat:#"select * from MIDS where MID = '%#'",MIDstr];
NSLog(BaseSQL);
const char *sqlStatement = [BaseSQL UTF8String];
//NSLog(BaseSQL);
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {
// Loop through the results and add them to the feeds array
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
NSString *returnString = [NSString stringWithFormat:#"%#",aName];
return returnString;
}
}
// Release the compiled statement from memory
sqlite3_finalize(compiledStatement);
}
sqlite3_close(database);
}
A. if sqlite3_step does not return any rows, you crash because you have declared that you are returning a NSString, but when there are no rows you return nothing.
The caller will try to read a NSString from the stack and thus end up dereferencing garbage.
To quickly fix the problem, write:
sqlite3_close(database);
return nil;
}
and make sure the caller handles nil results.
B/ If you do have data, your code never gets to call sqlite3_finalize and sqlite3_close because you return early:
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
[..]
return returnString;
while (sqlite3_step(sqlstatement) == SQLITE_ROW )
{
//Your code goes here
}
sqlite3_finalize(sqlstatement);
sqlite3_close(databaseRefObj);
close the database and finalize your statement after the while loop this helped me out,
I was successfully accessing my database to get a list of cities on the App launch. I tried running a second query against it right afterward to get the list of States but all that happens is that my app blows up with no usable error in the console (simply says "Program received signal: EXEC_BAD_ACCESS" and nothing more).
Here is the code, I was hoping someone could potentially explain to me what I'm doing wrong:
-(void) initializeDatabase{
// The database is stored in the application bundle
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"mydatabase.sqlite"];
// Open the database. The database was prepared outside the application.
if (sqlite3_open([path UTF8String], &database) == SQLITE_OK){
[self initializeCities:database];
[self initializeStates:database];
} else {
// Even though the open failed, call close to properly clean up resources.
sqlite3_close(database);
NSAssert1(0, #"Failed to open database with message '%s'.", sqlite3_errmsg(database));
// Additional error handling, as appropriate...
}
}
-(void) initializeCities:(sqlite3 *)db {
NSMutableArray *cityArray = [[NSMutableArray alloc] init];
self.cities = cityArray;
[cityArray release];
// Get the primary key for all cities.
const char *sql = "SELECT id FROM my_table ORDER BY state";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(db, sql, -1, &statement, NULL) == SQLITE_OK){
while (sqlite3_step(statement) == SQLITE_ROW){
int primaryKey = sqlite3_column_int(statement, 0);
City *city = [[City alloc] initWithPrimaryKey:primaryKey database:db];
[cities addObject:city];
[city release];
}
}
// "Finalize" the statement - releases the resources associated with the statement.
sqlite3_finalize(statement);
}
-(void) initializeStates:(sqlite3 *)db {
NSMutableArray *statesArray = [[NSMutableArray alloc] init];
self.states = statesArray;
[statesArray release];
// Get the primary key for all cities.
const char *sql = "SELECT DISTINCT state FROM my_table ORDER BY state";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(db, sql, -1, &statement, NULL) == SQLITE_OK){
// We "step" through the results - once for each row
while (sqlite3_step(statement) == SQLITE_ROW){
NSString *state;
state = (NSString *)sqlite3_column_text(statement, 0);
[states addObject:state];
[state release];
}
}
// "Finalize" the statement - releases the resources associated with the statement.
sqlite3_finalize(statement);
}
I can't debug this code as the debugger never hits my breakpoints at all.
If I remove the initializeStates method the app works as expected (albiet without a list of states).
You are releasing "state" without having allocated it. Try something like this:
while (sqlite3_step(statement) == SQLITE_ROW){
NSString *state = [[NSString alloc] initWithCString:(char*)sqlite3_column_text(statement, 0) encoding:NSASCIIStringEncoding];
//state = (NSString *)sqlite3_column_text(statement, 0);
[states addObject:state];
[state release];
}
Update: add cast above to fix compiler warning
Your problem is this:
NSString *state = (NSString *)sqlite3_column_text(statement, 0);
According to the documentation, sqlite3_column_text() returns a char*, not an NSString*.
Edit: You wouldn't have had this problem if you'd have used a wrapper ;)