I saved core data in SQLite file but I am wonder what's the table name in coredata I have three entities one of them is students.
While trying to using SQLite statement to read it it not enter the while
const char *sqlStatement = "SELECT * FROM students";
sqlite3_stmt *compiledStatement;
if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {
while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
NSLog(aName);
}
}
Any suggestion why not enter the if statement?
Well, you shouldn't be querying your CoreData tables directly, CoreData is there to abstract the storage from the code. You should use NSFetchRequest. But to answer your question, the table will normally be called zstudents.
Are you sure the table is actually called students? The core data underlying sqlite database generally has something like ZStudents as table names. You can use the free SQLite Database browser to view the schema in .sqlite files, but I have to wonder, why are writing SQL statements if you are using Core Data?
Related
I configured SQLCipher as the tutorial in their site... I can compile & Run the project.
But sqlite3_exec returns SQLITE_NOTADB when trying to execute a statement.
Please find code snippet below:
=================
NSString *dbPath = [self getDBPath];
BOOL success = [fileManager fileExistsAtPath:dbPath];
if(success) {
int sql_results = sqlite3_open([dbPath UTF8String], &SQLDB);
const char* key = [#"BIGSecret" UTF8String];
sqlite3_key(SQLDB, key, strlen(key));
if (sql_results == SQLITE_OK) {
NSString *sql;
const char *update_sql;
sql = [NSString stringWithFormat:#"DROP table %#",tablename];
update_sql = [sql cStringUsingEncoding:NSUTF8StringEncoding];
if(sqlite3_exec(SQLDB, update_sql, nil, nil, nil) == SQLITE_OK) {
NSLog(#"Good to go %# dropped",tablename);
}
else {
NSLog(#"Bad Delete Cat SQL: %s -- %d", update_sql,sql_results);
NSLog(#"error code %i", sql_results);
}
Am not able to get the issue, where I went wrong....
Thanks,
Ben
Cross posting from Mailing list:
I noticed in your code that you are only entering the block to
sqlite3_open if the database file exists. Are you by chance trying to
encrypt an existing standard SQLite database using SQLCipher using
this code? If so, calling sqlite3_key will not work that way. You'd
instead want to open the standard SQLite database, attach a new
encrypted database, and then export the data between the two. There
are some more details on this procedure here:
http://sqlcipher.net/sqlcipher-api/#sqlcipher_export
Once you're dealing with an encrypted database you can call
sqlite3_key as the first operation before using it.
I am new in sqlite in ios. Thus, what I have to do first and next in order to save data to different tables of database?
I have used Sqlite database in my various application, it works fine for me. You have to follow these steps for inserting the data in the tables of Sqlite database ...
1.First of all you need to create your database... I hope you have created and inserted in your project and also added linked framework libsqlite3.0.dylib and import these in your classes.
2. Replace your insertion method write this code ...
+(void)insertRecord:(NSString *)dbPath record:(NSMutableArray*)dataArray{
#try{
sqlite3_stmt *insertStmnt;
if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK){
for(int i=0; i<[dataArray count]; i++){
id record=[dataArray objectAtIndex:i];
NSString *insertQuery = [NSString stringWithFormat:#"INSERT INTO Table_Name (\"Column1\",\"Column2\",\"Column3\",\"Column4\",) VALUES('%#','%#','%#','%#')",[[record objectForKey:#"col1"] stringByReplacingOccurrencesOfString:#"'" withString:#"''"],[[record objectForKey:#"col2"] stringByReplacingOccurrencesOfString:#"'" withString:#"''"],[[record objectForKey:#"col3"] stringByReplacingOccurrencesOfString:#"'" withString:#"''"],[[record objectForKey:#"col4"] stringByReplacingOccurrencesOfString:#"'" withString:#"''"]];
const char *sql = [insertQuery cStringUsingEncoding:NSUTF8StringEncoding];
if(sqlite3_prepare_v2(database, sql, -1, &insertStmnt, NULL) == SQLITE_OK){
}else{
}
if(SQLITE_DONE != sqlite3_step(insertStmnt)){
}
}
}
}#catch (NSException *r) {
NSLog(#"UU %#",r);
}
}
Where record is the array of dictionary, which contains the values which you want to insert in the table or values get from the user.
stringByReplacingOccurrencesOfString:
The above method is necessary because if any user enters the data with single cote, then it will lead to your application crash.(you may remove this if you does not take input from the user)
Yes, You can also follow these links for better understanding..
1.http://www.techotopia.com/index.php/IOS_4_iPhone_Database_Implementation_using_SQLite
2.SQLite Tutorial
Hope it will work for you, if you have any query then may reply..
If you're using SQLite then go get FMDB as it will make your life alot easier. All that code above can be shrunk down to a thread safe call something like (off the top of my head, so probably not compile ready).
[queue inDatabase:^(FMDatabase *db) {
[db executeUpdateWithFormat:#"INSERT OR REPLACE INTO table (f1,f2) VALUES (%#, %#);", field1, field2];
DLog(#"insert error: %#", [db lastErrorMessage]);
}];
I am working on sqlite database , trying to insert into database but it is giving error "Error while inserting " Database is locked .
I searched some post and also write reset and finalize statement but it is giving same error.
Here is my code
if(addStmt == nil)
{
//const char *sql = "insert into Limittabel (limitAmt) Values(?)";
//const char *sql="INSERT INTO Limittabel (limitAmt, Profileid) VALUES(?, ?)";
const char *sql="insert into Limittabel (limitAmt,Profileid) Values (?,?)";
// Insert into Limittabel (limitAmt,Profileid) Values ($500,1)
if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK)
NSAssert1(0, #"Error while creating add statement. '%s'", sqlite3_errmsg(database));
}
sqlite3_bind_text(addStmt, 1, [limitAmt UTF8String], -1, SQLITE_TRANSIENT);
// NSString *str_id_poi = [[NSString alloc] initWithFormat:#"%d", [Profileid integerValue]];
// sqlite3_bind_text(addStmt, 2, [str_id_poi UTF8String], -1, SQLITE_TRANSIENT);
//sqlite3_bind_text(addStmt, 2, [ UTF8String], -1, SQLITE_TRANSIENT);
NSLog(#"***Storing END on Database ***");
if(SQLITE_DONE != sqlite3_step(addStmt))
{
NSAssert1(0, #"Error while inserting data. '%s'", sqlite3_errmsg(database));
} // sqlite3_finalize(addStmt);
else{
//sqlite3_last_insert_rowid;
limitid = sqlite3_last_insert_rowid(database);
NSLog(#"YES THE DATA HAS BEEN WRITTEN SUCCESSFULLY");
}
sqlite3_finalize(addStmt);
}
sqlite3_reset(addStmt);
//sqlite3_finalize(addStmt);
}
If I am not opening the database it is giving Database locked error, if opening database it is giving ' No such Table ' error
Please Help me.
Thanks
I don't understand the "if I am not opening the database it is giving Database locked error" comment, because you simply can't use a database without opening it. It makes no sense to call SQLite functions without first opening database. Maybe I'm not understanding this comment.
But ignoring that for a second, you later say, "if opening database it is giving 'No such table' error": Are you sure you're finding the database correctly? The problem is, if you open database and it's not found, then a blank database will be created. Are you sure this hasn't happened to you? If this may have happened to you, you might want to
Reset the simulator (if you're using simulator) or delete and reinstall the app to make sure any blank databases that sqlite3_open may have created for you will be removed; and
Check to make sure the database exists before you open it or replace your occurrence of sqlite3_open with sqlite3_open_v2 with a third parameter of SQLITE_OPEN_READWRITE and fourth parameter of NULL. See SQLite will not prepare query when accessing database in Xcode
As an aside, you don't mention whether you're opening this from the bundle or Documents, but generally I advise to programmatically copy from bundle to Documents and then open it from there.
If you're doing this on the simulator, I sometimes find it helpful to examine the database used by the simulator from my Mac. Thus, I go to "~/Library/Application Support/iPhone Simulator/5.1/Applications/" (replace the 5.1 with whatever version of your simulator you are using ... if the Library is hidden, unhide it from Terminal with chflags nohidden ~/Library), I then go into the directory for the particular application, go into it's Documents folder, and then open the database in the Mac command line sqlite3 program. You can use that to examine the database and make sure the db is as you expect it.
Just a few thoughts for the "no such table" error.
Here is link for creating, Open , inserting, and retrieve data from the SQLite database . It will help you.
SQLite Datase Create,Insert and Retrieve from the database Click here
jonty to deal with the database its compulsory that first we open the database and then we makes changes in database
and if it giving the error No such table then i recommend you check the existence of table in database i.e. such table created or not.
Try this code,
if(sqlite3_open([YourDatabasePath UTF8String],&db) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat: #"insert into Limittabel (limitAmt,Profileid) Values (?,?)"];
char *errmsg=nil;
if(sqlite3_exec(db, [querySQL UTF8String], NULL, NULL, &errmsg)==SQLITE_OK)
{
NSLog(#"YES THE DATA HAS BEEN WRITTEN SUCCESSFULLY");
}
}
sqlite3_close(db);
If this code doesn't work then there is a problem in your query, check your query again. this code works at my side.
HI folks,
i am getting all the tables from mydatabase.
my code is
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {
// Setup the SQL Statement and compile it for faster access
const char *sqlStatement = "SELECT * FROM sqlite_master where type='table'";
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) {
// Read the data from the result row
NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
[categoriesList addObject:aName];
}
}
// Release the compiled statement from memory
sqlite3_finalize(compiledStatement);
}
but i need few of table need to add in one array and reaming are need to add in another array.
for eg: i have tables like fruits,flowers,... And another tables like list1,list2,list3.
i need to get fruits,flowers... into one array and list1,list2... are needed to be added into another array.Because i am displaying all the items in fruits,flowers ....
And in list1,list2 i maintain the all the selected item among these categories.
but by using the above code i am getting all the list of tables.
can any one please help me.
(let me add comment if any one didn't get my question)
Thank u in advance.
how can i get tables differently.
You can test that the table name starts with "list" using hasPrefix:
if ([aName hasPrefix:#"list"]) // true if aName starts with "list"
[listCategoriesList addObject:aName];
else
[otherCategoriesList addObject:aName];
In order to separate the tables into two groups, you need some way to distinguish between them. Either you know in advance which tables should belong to list1, or list1 should contain all the tables that start with 'f', or all the tables with an odd number of rows, or...
I'm writing an application for the iPhone that communicates with a SQLite database but I'm running into a small problem. Whenever I try to query information based on a condition that contains an apostrophe, no results are returned.... even if a result that matches the requested condition exists. Let me give some specifics...
SQLite Table
Row--Column1--Column2---------
Test Data - 001
User's Data - 002
Objective-C Code
//Create the sql statement
sqlite3_stmt *sqlStatement;
//Create the name of the category that will be passed in
NSString *categoryName = #"User's Data";
//Create the rest of the SQL query
NSString *sqlQuery = "SELECT * FROM theTableName WHERE Column1 = ?";
//If there are no errors in the SQL query
if (sqlite3_prepare_v2(theDatabase, sqlQuery, -1, &sqlStatement, nil) == SQLITE_OK)
{
//Bind the category name to the sql statement
sqlite3_bind_text(sqlStatement, 1, [categoryName UTF8String], -1, SQLITE_TRANSIENT);
//While there are rows being returned
while (sqlite3_step(sqlStatement) == SQLITE_ROW)
{
//Retrieve row data
}
}
else
{
//Save error message to the application log and terminate the app
NSAssert1(0,#"Error: Failed to prepare the SQL statement with message '%s'.", sqlite3_errmsg(database));
}
//Reset the sql statement
sqlite3_reset(sqlStatement);
I'm semi-new to objective C, so my first thought when writing this code was to sanitize the user inputs. But after doing some research, I read that the sqlite3_bind calls do the necessary sanitation for you. But whenever the code runs, the while loop is skipped right over because there are no rows being returned. It should return the second row from the database table. If I copy/paste the exact same SQL query into a SQL managing program (I use SQLite Manager) (and with the necessary query sanitation of course), it returns the correct data.
I've spent a long time trying to debug this myself and even a greater amount of time trying to search online for a similar problem being explained and resolved, but to no avail. As of now, I just disabled the user's ability to key in an apostrophe on the iPhone's virtual keyboard. But this is a feature I'd love to include in my finished product. Can anyone here offer me any helpful tips? Any kind of help would be greatly appreciated.
For sqlite your request will be (as you can see it is even wrong highlighted):
SELECT * FROM theTableName WHERE Column1 = User's data
And it will wait for the closing ' symbol
You should echo ' symbol, for example in following way:
NSString *sqlQuery = [NSString stringWithFormat:#"SELECT * FROM tableName WHERE Column1=\"%#\"", categoryName];
In this case query will be
select * from theTableName where column1="User's data"
that is completely legal query.
In this case you don't need binding any more and final code will look like:
if (sqlite3_prepare_v2(database, [sqlQuery UTF8String], -1, &sqlStatement, nil) == SQLITE_OK)
{
//While there are rows being returned
while (sqlite3_step(sqlStatement) == SQLITE_ROW)
{
//Retrieve row data
}
}
else
{
//Save error message to the application log and terminate the app
NSAssert1(0,#"Error: Failed to prepare the SQL statement with message '%s'.", sqlite3_errmsg(database));
}
The official character is ''
sanitize with:
NSString *stringToSanitize = #"This is the value with ' character";
NSString *sanitized = [stringToSanitize stringByReplacingOccurrencesOfString:#"'"
withString:#"''"];
Then you can use it on your querys