I have a DBManager wich is fetching data from database (sqlite file). All other queries are fine, but this one seems to be somehow not working
-(NSArray *)readCountries{
NSLog(#"[DBManager] readCountries");
NSMutableArray *countriesArray = [[NSMutableArray alloc] init];
//open db from users filesystem
if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) {
const char* sql = "SELECT DISTINCT country FROM aed ORDER BY rowid";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) == SQLITE_OK) {
//loop through results
while (sqlite3_step(statement) == SQLITE_ROW) {
//read data from record
NSString *_country;
char* tmpCountry = (char*)sqlite3_column_text(statement, 1);
NSLog(#"tmpCountry = %#", [NSString stringWithUTF8String:tmpCountry]);
if (tmpCountry != NULL) {
_country = [NSString stringWithUTF8String:tmpCountry];
}else{
_country = #"n/a";
}
NSLog(#"country = %#", _country);
[countriesArray addObject:_country];
}
}
//finalize statement
sqlite3_finalize(statement);
}
//close database
sqlite3_close(database);
NSLog(#"[DBManager] countriesArray has %d objects", [countriesArray count]);
return (NSArray*)countriesArray;
}
All I get from logs, that my array has 5 objects, which is fine - but it souldn't be only "n/a"... any idea? Other queries are good, they mostly use sqlite3_column_text so I don't get it, why it's not working here - maybe a fresh eye will help.
This is a confusing inconsistency with the sqlite C-api. When using the sqlite3_column_xxx functions, the column index is 0-based. But with the sqlite3_bind_xxx functions, the column index is 1-based.
Change this:
char* tmpCountry = (char*)sqlite3_column_text(statement, 1);
to:
char* tmpCountry = (char*)sqlite3_column_text(statement, 0);
BTW - you should add else statements to your sqlite3_open and sqlite3_prepare calls. If they fail you can log the error using the sqlite3_errmsg function.
Related
I had debugged code but don't know why While statement is not executing . After putting NSlog I came to know it's mismatching the result. 101 and SQLITE_ROW is equal to 100.
But query has result. If I fetch Select * from table name its returning me result and while statement executes. If I fetch result
sql_stmt = [NSString stringWithFormat:#"SELECT * FROM DeviceType WHERE upper(TypeName) = upper('%#')", deviceType];
While statement never execute so please help. don't know where is the problem.
Here is the code:
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
NSString* documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:#"ClientDB.sqlite"];
NSString* sql_stmt = [self searchStringForLocalData];
BOOL found = NO;
if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
{
const char* sql1 = [sql_stmt UTF8String];
sqlite3_stmt *statement;
NSNumber *typeCount;
typeCount = 0;
if (sqlite3_prepare_v2(database, sql1, -1, &statement, NULL) == SQLITE_OK)
{
NSLog(#" %d, %d ",sqlite3_step(statement),SQLITE_ROW);
while (sqlite3_step(statement) == SQLITE_ROW) {
// The second parameter indicates the column index into the result set.
int primaryKey1 = sqlite3_column_int(statement, 0);
NSNumber *typeId = [[NSNumber alloc] initWithInt:primaryKey1];
NSString *typeName =[NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 1)];
NSString* sql_stmt1 = [NSString stringWithFormat:#"SELECT COUNT(*) FROM Devices WHERE DeviceTypeId =%d",primaryKey1];
const char *sql1 = [sql_stmt1 UTF8String];
sqlite3_stmt *statement;
NSNumber *typeCount;
typeCount = 0;
As already mentioned in a comment, the code calls sqlite3_step once for the NSLog, and then a second time in the condition of the while loop.
If your query returns exactly one record, the first sqlite3_step call will step to that record, and the second sqlite3_step call will then report (correctly) that no further results are available.
Just remove that NSLog call.
Alternatively, call sqlite3_step only once, and use the same return value for both the logging and the loop:
int rc;
...
while (1) {
rc = sqlite3_step(statement);
NSLog(#" %d, %d ", rc, SQLITE_ROW);
if (rc != SQLITE_ROW)
break;
...
}
if (rc != SQLITE_DONE)
NSLog(#"error: %s", sqlite3_errmsg(database));
Try to use the following syntax
while(sqlite3_step(stmt)!=SQLITE_DONE)
{
//do ur processing
for(i=0;i<NO_OF_COLS;i++)
{
char * tmp1=sqlite3_column_text(stmt,i);
if(tmp1!=NULL)
{
//use the value
}
else
{
//use a default
}
}
}
It shows that your table is totally empty. You may want to check your insert whether it works correctly. If you're using sqlite3_prepare_v2 to prepare your statement with some ? marks, remember to execute your query after all. Simply like this:
if(sqlite3_step(stmt) == SQLITE_DONE) NSLog(#"INSERTED");
else NSLog(#"NO INSERTED");
Note: It will display error only if your query is wrong, but not your prepared statement was executed or not.
I'm trying to get data from my DB but I have some problem.
Here is my code:
NSString *action=[[NSString alloc]init];
NSString *queryStatement = [NSString stringWithFormat:#"SELECT ACTIONNAME FROM ACTIONS WHERE ACTIONSYMBOL = '%#'", symbol];
// Prepare the query for execution
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(database, [queryStatement UTF8String], -1, &statement, NULL) == SQLITE_OK)
{
// Create a new address from the found row
while (sqlite3_step(statement) == SQLITE_ROW) {
action = [NSString stringWithUTF8String:(char*)sqlite3_column_text(statement, 1)]; // fails on this line
}
sqlite3_finalize(statement);
return action;
}
(the parameter symbol come from outside)
When I run this, it fails at the line with the call to stringWithUTF8String with sqlite3_column_text results.
You probably want to collect the results in an NSMutableArray:
NSMutableArray *action = [[NSMutableArray alloc] init];
...
while (sqlite3_step(statement) == SQLITE_ROW) {
[action addObject:[NSString stringWithUTF8String:(char*)sqlite3_column_text(statement, 0)]];
}
...
You can then see what was collected later:
for (NSString *s in action) {
NSLog(#"%#", s);
}
EDIT As pointed out in #Rob's answer, the first column is 0, not 1.
In your call to sqlite3_column_text, you're using the index 1, but it takes a zero-based index. Use 0 instead of 1. See the SQLite sqlite_column_XXX documentation, which says:
The leftmost column of the result set has the index 0.
By the way, since stringWithUTF8String throws an exception if you pass it a NULL value, it's often safer to check the result if sqlite3_column_text is not NULL before proceeding, and handle the error gracefully otherwise. Also, you might want to check for sqlite3_step and sqlite3_prepare_v2 errors, like so:
NSString *queryStatement = [NSString stringWithFormat:#"SELECT ACTIONNAME FROM ACTIONS WHERE ACTIONSYMBOL = '%#'", symbol]; // note, it can be dangerous to use `stringWithFormat` to build SQL; better to use `?` placeholders in your SQL and then use `sqlite3_bind_text` to bind the `symbol` value with the `?` placeholder
if (sqlite3_prepare_v2(database, [queryStatement UTF8String], -1, &statement, NULL) == SQLITE_OK)
{
int rc;
while ((rc = sqlite3_step(statement)) == SQLITE_ROW) {
const unsigned char *value = sqlite3_column_text(statement, 0); // use zero
if (value) {
NSString *action = [NSString stringWithUTF8String:(const char *)value];
// now do whatever you want with `action`, e.g. add it to an array or what
} else {
// handle the error (or NULL value) gracefully here
}
// make sure to check for errors in `sqlite3_step`
if (rc != SQLITE_DONE)
{
NSLog(#"%s: sqlite3_step failed: %s", __FUNCTION__, sqlite3_errmsg(database));
}
}
}
else
{
NSLog(#"%s: sqlite3_prepare_v2 failed: %s", __FUNCTION__, sqlite3_errmsg(database));
}
Incidentally, as the above illustrates, to correctly perform all of the error checking is a little cumbersome. This is where FMDB can be useful, simplifying the above to (where db is an FMDatabase object that has been opened):
FMResultSet *rs = [db executeQuery:#"SELECT ACTIONNAME FROM ACTIONS WHERE ACTIONSYMBOL = ?", symbol];
if (!rs) {
NSLog(#"%s: executeQuery failed: %#", __FUNCTION__, [db lastErrorMessage]);
return;
}
while ([rs next]) {
NSString *action = [rs stringForColumnIndex:0];
// do whatever you want with `action` here
}
[rs close];
And if you use ? placeholders (rather than using stringWithFormat to build your SQL, which is dangerous) the benefits of using FMDB are even more compelling.
I am deleting records from the database.and it is working fine .But it is crashing when there is no data in the database. The code is given Below
int noOfRecordsDeleted;
[self openDatabaseConnection];
// query = [NSString stringWithFormat:#"delete from %# where %#",query];
NSLog(#"del query=%#",query);
const char *sql = [query cStringUsingEncoding:NSUTF8StringEncoding];
sqlite3_stmt *statement = nil;
if(sqlite3_prepare_v2(dataBaseConnection,sql, -1, &statement, NULL)!= SQLITE_OK)
{
NSAssert1(0,#"error preparing statement",sqlite3_errmsg(dataBaseConnection));
}
else
{
int success = sqlite3_step(statement);
NSLog(#"%d",success);
}
sqlite3_finalize(statement);
noOfRecordsDeleted = sqlite3_changes(dataBaseConnection);
[self closeDatabaseConnection];
return noOfRecordsDeleted;
It is working fine. But if i am adding data i empty database it is crashing
[self openDatabaseConnection];
NSString *query;
query = [NSString stringWithFormat:#"insert into Userdetail(aboutMe,anniversary,areacode,birthdate,device_id,chat_id,emailid,gender ,image,last_login,latitute,longitude,Looking_For,mobilenumber,mobilenumber1 ,mobilenumber2,mood,name,password,place,profileviews,statusmessage) values ('%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#','%#')",aboutMe,anniversarydate,areacode,birthdate,
device_id,chat_id,email_id,gender,image,last_login,latitude,longitude,looking_for,mobilenumber,mobilenumber1,mobilenumber2,mood,name,password,place,profileviews,statusmessage];
NSLog(#"saveNewTemplateData query=%#",query);
const char *sql = [query cStringUsingEncoding:NSUTF8StringEncoding];
sqlite3_stmt *statement = nil;if(sqlite3_prepare_v2(dataBaseConnection,sql , -1, &statement, NULL)!= SQLITE_OK)
{
NSAssert1(0,#"error preparing statement",sqlite3_errmsg(dataBaseConnection));
}
else
{
sqlite3_step(statement);
}
sqlite3_finalize(statement);
[self closeDatabaseConnection];
above is the code
First of all check the Database is empty or not by using the following statement
if(sqlite3_column_text(statement, 0) != nil){//Data exists}
Then in the if method add the code to delete the dataBase.
It works fine.
query = [NSString stringWithFormat:#"delete from %# where %#",query];
what does this query means I think its the mistake of your query please doublecheck it
if the error persists programmatically check
by using if(sqlite3_column_text(statement, 0) != nil)
One issue I saw that you are calling sqlite3_finalize(statement); regardless the state of sqlite3_prepare_v2. You only need to call sqlite3_finalize if the sqlite3_prepare_v2 executed successfully.
Change that to:
if(sqlite3_prepare_v2(dataBaseConnection,sql, -1, &statement, NULL)!= SQLITE_OK)
{
NSAssert1(0,#"error preparing statement",sqlite3_errmsg(dataBaseConnection));
}
else
{
int success = sqlite3_step(statement);
NSLog(#"%d",success);
sqlite3_finalize(statement);
}
if (condition for check database empty (select * from table)){
}else{
//Perform Delete operation
}
I have SQLite database with 5 columns named: Name, ID, ChildID, ParentID, BrotherID.
In this database I have many records and I want to store one of all columns value in array and return this array. For example I want to get all value in ParentID column. I use this query code:
Select ParentID from Table1 (Table1 is name of table)
This is my code for get array from certain column :
/*==================================================================
METHOD FOR GETTING MIDIFIED FROM DATABASE
==================================================================*/
- (NSMutableArray*)readingModified
{
ModiArray = [[NSMutableArray alloc] init];
// Setup the database object
sqlite3 *database2;
// Open the database from the users filessytem
if(sqlite3_open([[self DatabaseSqlite] UTF8String], &database2) == SQLITE_OK)
{
// Setup the SQL Statement and compile it for faster access
//SQLIte Statement
NSString *sqlStatement_userInfo =[NSString stringWithFormat:#"Select ParentID from Table1"];
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database2, [sqlStatement_userInfo UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK)
{
// Loop through the results and add them to the feeds array
while(sqlite3_step(compiledStatement) == SQLITE_ROW)
{
// Init the Data Dictionary
NSMutableDictionary *_dataDictionary2=[[NSMutableDictionary alloc] init];
NSString *_recordParentID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];
[_dataDictionary2 setObject:[NSString stringWithFormat:#"%#",_recordModified] forKey:#"ParentID"];
[array addObject:_dataDictionary2];
}
}
else
{
NSLog(#"No Data Found");
}
// Release the compiled statement from memory
sqlite3_finalize(compiledStatement);
}
sqlite3_close(database2);
return ModiArray;
}
please tell me my mistake.
my friend a few be careful.
this code is right but in line you mistake :
[array addObject:_dataDictionary2];
instead array put ModiArray
/*==================================================================
METHOD FOR GETTING MIDIFIED FROM DATABASE
==================================================================*/
- (NSMutableArray*)readingModified
{
ModiArray = [[NSMutableArray alloc] init];
// Setup the database object
sqlite3 *database2;
// Open the database from the users filessytem
if(sqlite3_open([[self DatabaseSqlite] UTF8String], &database2) == SQLITE_OK)
{
// Setup the SQL Statement and compile it for faster access
//SQLIte Statement
NSString *sqlStatement_userInfo =[NSString stringWithFormat:#"Select ParentID from Table1"];
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database2, [sqlStatement_userInfo UTF8String], -1, &compiledStatement, NULL) == SQLITE_OK)
{
// Loop through the results and add them to the feeds array
while(sqlite3_step(compiledStatement) == SQLITE_ROW)
{
// Init the Data Dictionary
NSMutableDictionary *_dataDictionary2=[[NSMutableDictionary alloc] init];
NSString *_recordParentID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];
[_dataDictionary2 setObject:[NSString stringWithFormat:#"%#",_recordModified] forKey:#"ParentID"];
[ModiArray addObject:_dataDictionary2];
}
}
else
{
NSLog(#"No Data Found");
}
// Release the compiled statement from memory
sqlite3_finalize(compiledStatement);
}
sqlite3_close(database2);
return ModiArray;
}
You are adding object to array and allocating and returning ModiArray.
hi all
i have some problem in using sqlite in IOS. i have select data from database, and then i want to save that data in a variable. But when i use while(sqlite3_step(statement) == SQLITE_ROW) loop, the code never execute.
here is my code :
-(void)retrieveProjectNameFromDb:(NSString *)segmenId{
NSString *query;
NSString *nameProjectStr;
NSString *dbPath = [[NSBundle mainBundle] pathForResource:#"database" ofType:#"sqlite"];
if (sqlite3_open([dbPath UTF8String], &db) != SQLITE_OK) {
sqlite3_close(db);
NSAssert(0, #"Database failed to open.");
}else {
query = [NSString stringWithFormat:#"SELECT remote_projectname, remote_base_uri FROM REMOTE_SETTING WHERE remote_settingid = '%#' ORDER BY remote_projectname", segmenId];
NSLog(#"query : %#", query);
}
sqlite3_stmt *statement;
if(sqlite3_prepare_v2(db, [query UTF8String], -1, &statement, nil)==SQLITE_OK){
NSLog(#"sqlite row : %d", SQLITE_ROW);
NSLog(#"sqlite 3 : %d", sqlite3_step(statement));
while (sqlite3_step(statement) == SQLITE_ROW) {
char *nameProject = (char *)sqlite3_column_text(statement, 0);
if (nameProject == nil) {
NSLog(#"UNNAMED");
}else {
NSLog(#"else");
nameProjectStr = [NSString stringWithUTF8String:nameProject];
}
projectName.text = nameProjectStr;
nameProject = nil;
}
NSLog(#"project name : %#", projectName.text);
sqlite3_close(db);
}
}
when i nslog the value, sqlite3_step(statement) always show 101 and sqlite_row always show 100. Why it can happen??
can somebody help me, please?
thank you
Regards
-risma-
As you mentioned sqlite3_step(statement) always show 101 which means sqlite3_step has finished executions hence it means your sql query is not returning any rows from database. I would recommend you to first check in database if any record exists in table REMOTE_SETTING for remote_settingid which you are referring.
For your reference I took following constant snippet from sqlite.org
#define SQLITE_DONE 101 /* sqlite_step() has finished executing */
Remove the NSLog entry in which you are having sqlite3_step(). Since you have your NSLog statement executing sqlite3_step(), the record is already stepped through here. Hence, your while loop won't execute as there are no more rows to step through.
I think this will surely help you. :)
From your description of the logging output I would guess that your query is returning an empty row set. However I can see two other problems here:
You discard the result of your first call to sqlite3_step, because you log it then immediately call sqlite3_step again. That means you will miss the first row.
You probably should not be closing the database after a single query. You should finalize the statement after the query, but only close the database when your app shuts down.
Try:
if(sqlite3_prepare_v2(db, [query UTF8String], -1, &statement, nil)==SQLITE_OK){
NSLog(#"sqlite row : %d", SQLITE_ROW);
int stepResult = sqlite3_step(statement);
NSLog(#"sqlite 3 : %d", stepResult);
while (stepResult == SQLITE_ROW) {
char *nameProject = (char *)sqlite3_column_text(statement, 0);
if (nameProject == nil) {
NSLog(#"UNNAMED");
}else {
NSLog(#"else");
nameProjectStr = [NSString stringWithUTF8String:nameProject];
}
projectName.text = nameProjectStr;
nameProject = nil;
stepResult = sqlite3_step(statement);
}
NSLog(#"project name : %#", projectName.text);
sqlite3_finalize(&statement);
}
Try with something like this..
sqlite3 *database1;
NSString *sqlStatement1 = #"";
if(sqlite3_open([databasePath UTF8String], &database1) == SQLITE_OK)
{
sqlStatement1 = [NSString stringWithString:#"SELECT uniqueid from shortlisted"];
sqlite3_stmt *compiledStatement1;
if(sqlite3_prepare_v2(database1, [sqlStatement1 cStringUsingEncoding:NSUTF8StringEncoding], -1, &compiledStatement1, NULL) == SQLITE_OK)
{
while(sqlite3_step(compiledStatement1) == SQLITE_ROW)
{
NSString * str = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
}
}
sqlite3_finalize(compiledStatement1);
sqlite3_close(database1);
}
Also close database instance whenever you open them.. if you are not closing an instance then that can cause issues..
Sorry I am pasting this from my project.. but actually I am in a bit hurry... I'll modify this answer when I reach home...