I am running a background task that goes out and downloads a JSON file, pareses it, then adds it to the contents to a SQLite database.
I am getting a couple of errors when it runs.
Caused by: android.database.CursorWindowAllocationException: Cursor
window allocation of 2048 kb failed. # Open Cursors=728 (# cursors
opened by this proc=728)
E/CursorWindow: Could not allocate CursorWindow
'/data/data/com.mycompany.inventory/databases/dbInventory.sql' of size
2097152 due to error -12.
The JSON has about 1500 items in it.
Here is the method my async task calls:
public void addModelsToDB(JSONObject dict){
String insertQuery = "";
String deleteQuery = "DROP TABLE IF EXISTS 'tblModels'";
String createQuery = "CREATE TABLE 'tblModels' ('modelsID' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,'makeKey' INTEGER, 'modelName' TEXT, 'modelKey' INTEGER)";
Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);
cursor.moveToFirst();
cursor = dbLocals.executeRawQuery(createQuery, null);
cursor.moveToFirst();
try {
JSONArray dicRecordSet = dict.getJSONArray("Recordset");
JSONObject dicRecords = dicRecordSet.getJSONObject(0);
JSONArray arrRecords = dicRecords.getJSONArray("Record");
for (int i = 0; i < arrRecords.length(); i++) {
JSONObject record = arrRecords.getJSONObject(i);
insertQuery = "INSERT INTO 'tblModels' VALUES(" + null + ", "
+ record.getString("MODMAKlMakeKey") + ", '"
+ record.getString("MODvc50Name").replaceAll("'", "''") + "', "
+ record.getString("MODlModelKey")
+")";
cursor = dbLocals.executeRawQuery(insertQuery, null);
cursor.moveToFirst();
}
} catch (JSONException e) {
e.printStackTrace();
}
cursor.close();
}
My database a manager returns a cursor.
public Cursor executeRawQuery(String query, String[] selectionArgs) {
Cursor cursor = databaseConn.rawQuery(query, selectionArgs);
return cursor;
}
What am I doing wrong?
You can't reuse the cursor variable because it shadows the original one, and therefore you can't close it:
Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);
then
cursor = dbLocals.executeRawQuery(insertQuery, null);
this second assignment means you can't close the original cursor.
Also, why are you creating the table here?
Edit:
Use it like this:
public void addModelsToDB(JSONObject dict){
String insertQuery = "";
String deleteQuery = "DROP TABLE IF EXISTS 'tblModels'";
String createQuery = "CREATE TABLE 'tblModels' ('modelsID' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,'makeKey' INTEGER, 'modelName' TEXT, 'modelKey' INTEGER)";
Cursor cursor = dbLocals.executeRawQuery(deleteQuery, null);
try {
cursor.moveToFirst();
cursor = dbLocals.executeRawQuery(createQuery, null);
cursor.moveToFirst();
} finally {
cursor.close();
}
try {
JSONArray dicRecordSet = dict.getJSONArray("Recordset");
JSONObject dicRecords = dicRecordSet.getJSONObject(0);
JSONArray arrRecords = dicRecords.getJSONArray("Record");
for (int i = 0; i < arrRecords.length(); i++) {
JSONObject record = arrRecords.getJSONObject(i);
insertQuery = "INSERT INTO 'tblModels' VALUES(" + null + ", "
+ record.getString("MODMAKlMakeKey") + ", '"
+ record.getString("MODvc50Name").replaceAll("'", "''") + "', "
+ record.getString("MODlModelKey")
+")";
cursor = dbLocals.executeRawQuery(insertQuery, null);
try {
cursor.moveToFirst();
} finally {
cursor.close();
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
You should close cursors after using them. Inside the loop, you are creating a cursor every iteration, without ever closing it. Apparently there is a limit for the number of open cursors and you hit that limit.
i have an issue with both functions
// Insert a new contact in database
public void insertInSignature(String TITLE_SI) {
try {
// Open Android Database
Boolean b = checkIsDataAlreadyInDBorNot("DELIVERY_SLIP",
"TITLE_SI", TITLE_SI);
if(b==false)
{
// cursor is empty
ContentValues initialValues = new ContentValues();
initialValues.put("TITLE_SI", TITLE_SI);
db.insertWithOnConflict("DELIVERY_SLIP", null, initialValues,
SQLiteDatabase.CONFLICT_IGNORE);
}
} catch (SQLException sqle) {
Log.e(TAG, "insertUser Error");
Log.e(TAG, "Exception : " + sqle);
} finally {
// Close Android Database
databaseHelper.close();
}
}
public boolean checkIsDataAlreadyInDBorNot(String TableName,
String dbfield, String fieldValue) {
db = databaseHelper.getWritableDatabase();
String Query = "Select * from " + TableName + " where " + dbfield + "="
+ "`"+ fieldValue+"`";
Cursor cursor = db.rawQuery(Query, null);
if (cursor.getCount() <= 0) {
return false;
}
return true;
}
I have this function , I'm inserting signature when it's not on the database.. But the function boolean return an SQLexception i don't know why i found informations about the form , but not for my problem.
Here my log.
http://hpics.li/0ae4ba2
I just want to know if the row exist on my database
here my table.
http://hpics.li/1fd3d9a
Thanks by advance if you need for informations ask me
In SQL, strings are delimited with single quotes ', not backticks `.
To avoid such formatting problems, and SQL injections, you should use parameters instead:
String query = "SELECT * FROM " + TableName + " WHERE " + dbfield + "= ?";
Cursor cursor = db.rawQuery(query, new String[] { fieldValue });
Instead of doing a query every time you want to insert, why not make the TITLE_SI column UNIQUE with ON CONFLICT IGNORE or ONC CONFLICT REPLACE? Then you don't need to check, you simply insert and let the uniqueness constraint manage this for you.
I would like to check whether a record exists or not.
Here is what I've tried:
MainActivity.class
public void onTextChanged(CharSequence s, int start, int before, int count) {
System.out.println("Ontext changed " + new String(s.toString()));
strDocumentFrom = s.toString();
if(s.toString().isEmpty()){
} else {
try{
strTransactionDate = dbHelper.getTransactionDateByDocumentNumber(strDocumentFrom);
//strTotalAmount = dbHelper.getTotalAmountByDocumentNumber(strDocumentFrom);
//strVan = dbHelper.getVanByDocumentNumber(strDocumentFrom);
//etTransactionDate.setText(strTransactionDate);
//etTotalAmount.setText(strTotalAmount);
//Log.d("Van", "" + strVan);
//etVan.setText(strVan);
} catch (SQLiteException e) {
e.printStackTrace();
Toast.makeText(ReceivingStocksHeader.this,
"Document number does not exist.", Toast.LENGTH_SHORT).show();
}
}
DBHelper.class
// TODO DISPLAYING RECORDS TO TRANSRCVHEADER
public String getTransactionDateByDocumentNumber(String strDocumentNumber){
String[] columns = new String[]{KEY_TRANSACTIONDATE};
Cursor c = myDataBase.query(TBL_INTRANS,
columns, null,
null, null, null, null, null);
if(c != null){
c.moveToFirst();
String date = c.getString(0);
return date;
} else {
Log.d("Error", "No record exists");
}
return null;
}
But it doesn't get it to the catch block to display the toast.
What am I doing wrong in here?
public static boolean CheckIsDataAlreadyInDBorNot(String TableName,
String dbfield, String fieldValue) {
SQLiteDatabase sqldb = EGLifeStyleApplication.sqLiteDatabase;
String Query = "Select * from " + TableName + " where " + dbfield + " = " + fieldValue;
Cursor cursor = sqldb.rawQuery(Query, null);
if(cursor.getCount() <= 0){
cursor.close();
return false;
}
cursor.close();
return true;
}
I hope this is useful to you...
This function returns true if record already exists in db. Otherwise returns false.
These are all good answers, however many forget to close the cursor and database. If you don't close the cursor or database you may run in to memory leaks.
Additionally: You can get an error when searching by String that contains non alpha/numeric characters. For example: "1a5f9ea3-ec4b-406b-a567-e6927640db40". Those dashes (-) will cause an unrecognized token error. You can overcome this by putting the string in an array. So make it a habit to query like this:
public boolean hasObject(String id) {
SQLiteDatabase db = getWritableDatabase();
String selectString = "SELECT * FROM " + _TABLE + " WHERE " + _ID + " =?";
// Add the String you are searching by here.
// Put it in an array to avoid an unrecognized token error
Cursor cursor = db.rawQuery(selectString, new String[] {id});
boolean hasObject = false;
if(cursor.moveToFirst()){
hasObject = true;
//region if you had multiple records to check for, use this region.
int count = 0;
while(cursor.moveToNext()){
count++;
}
//here, count is records found
Log.d(TAG, String.format("%d records found", count));
//endregion
}
cursor.close(); // Dont forget to close your cursor
db.close(); //AND your Database!
return hasObject;
}
Raw queries are more vulnerable to SQL Injection. I will suggest using query() method instead.
public boolean Exists(String searchItem) {
String[] columns = { COLUMN_NAME };
String selection = COLUMN_NAME + " =?";
String[] selectionArgs = { searchItem };
String limit = "1";
Cursor cursor = db.query(TABLE_NAME, columns, selection, selectionArgs, null, null, null, limit);
boolean exists = (cursor.getCount() > 0);
cursor.close();
return exists;
}
Source: here
SELECT EXISTS with LIMIT 1 is much faster.
Query Ex: SELECT EXISTS (SELECT * FROM table_name WHERE column='value' LIMIT 1);
Code Ex:
public boolean columnExists(String value) {
String sql = "SELECT EXISTS (SELECT * FROM table_name WHERE column='"+value+"' LIMIT 1)";
Cursor cursor = database.rawQuery(sql, null);
cursor.moveToFirst();
// cursor.getInt(0) is 1 if column with value exists
if (cursor.getInt(0) == 1) {
cursor.close();
return true;
} else {
cursor.close();
return false;
}
}
You can use SELECT EXISTS command and execute it for a cursor using a rawQuery,
from the documentation
The EXISTS operator always evaluates to one of the integer values 0
and 1. If executing the SELECT statement specified as the right-hand
operand of the EXISTS operator would return one or more rows, then the
EXISTS operator evaluates to 1. If executing the SELECT would return
no rows at all, then the EXISTS operator evaluates to 0.
I have tried all methods mentioned in this page, but only below method worked well for me.
Cursor c=db.rawQuery("SELECT * FROM user WHERE idno='"+txtID.getText()+"'", null);
if(c.moveToFirst())
{
showMessage("Error", "Record exist");
}
else
{
// Inserting record
}
One thing the top voted answer did not mention was that you need single quotes, 'like this', around your search value if it is a text value like so:
public boolean checkIfMyTitleExists(String title) {
String Query = "Select * from " + TABLE_NAME + " where " + COL1 + " = " + "'" + title + "'";
Cursor cursor = database.rawQuery(Query, null);
if(cursor.getCount() <= 0){
cursor.close();
return false;
}
cursor.close();
return true;
}
Otherwise, you will get a "SQL(query) error or missing database" error like I did without the single quotes around the title field.
If it is a numeric value, it does not need single quotes.
Refer to this SQL post for more details
SQLiteDatabase sqldb = MyProvider.db;
String Query = "Select * from " + TABLE_NAME ;
Cursor cursor = sqldb.rawQuery(Query, null);
cursor.moveToLast(); //if you not place this cursor.getCount() always give same integer (1) or current position of cursor.
if(cursor.getCount()<=0){
Log.v("tag","if 1 "+cursor.getCount());
return false;
}
Log.v("tag","2 else "+cursor.getCount());
return true;
if you not use cursor.moveToLast();
cursor.getCount() always give same integer (1) or current position of cursor.
Code :
private String[] allPushColumns = { MySQLiteHelper.COLUMN_PUSH_ID,
MySQLiteHelper.COLUMN_PUSH_TITLE, MySQLiteHelper.COLUMN_PUSH_CONTENT, MySQLiteHelper.COLUMN_PUSH_TIME,
MySQLiteHelper.COLUMN_PUSH_TYPE, MySQLiteHelper.COLUMN_PUSH_MSG_ID};
public boolean checkUniqueId(String msg_id){
Cursor cursor = database.query(MySQLiteHelper.TABLE_PUSH,
allPushColumns, MySQLiteHelper.COLUMN_PUSH_MSG_ID + "=?", new String [] { msg_id }, null, null, MySQLiteHelper.COLUMN_PUSH_ID +" DESC");
if(cursor.getCount() <= 0){
return false;
}
return true;
}
Here's a simple solution based on a combination of what dipali and Piyush Gupta posted:
public boolean dbHasData(String searchTable, String searchColumn, String searchKey) {
String query = "Select * from " + searchTable + " where " + searchColumn + " = ?";
return getReadableDatabase().rawQuery(query, new String[]{searchKey}).moveToFirst();
}
because of possible data leaks best solution via cursor:
Cursor cursor = null;
try {
cursor = .... some query (raw or not your choice)
return cursor.moveToNext();
} finally {
if (cursor != null) {
cursor.close();
}
}
1) From API KITKAT u can use resources try()
try (cursor = ...some query)
2) if u query against VARCHAR TYPE use '...' eg. COLUMN_NAME='string_to_search'
3) dont use moveToFirst() is used when you need to start iterating from beggining
4) avoid getCount() is expensive - it iterates over many records to count them. It doesn't return a stored variable. There may be some caching on a second call, but the first call doesn't know the answer until it is counted.
Try to use cursor.isNull method.
Example:
song.isFavorite = cursor.isNull(cursor.getColumnIndex("favorite"));
You can use like this:
String Query = "Select * from " + TABLE_NAME + " where " + Cust_id + " = " + cust_no;
Cursor cursorr = db.rawQuery(Query, null);
if(cursor.getCount() <= 0){
cursorr.close();
}
cursor.close();
private boolean checkDataExistOrNot(String columnName, String value) {
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM" + TABLE_NAME + " WHERE " + columnName + " = " + value;
Cursor cursor = sqLiteDatabase.rawQuery(query, null);
if (cursor.getCount() <= 0) {
cursor.close();
return false; // return false if value not exists in database
}
cursor.close();
return true; // return true if value exists in database
}
I prefer to do it this way because it's fast and less expensive than other methods:
Cursor cursor = db.rawQuery("SELECT 1 FROM table WHERE condition = 1 LIMIT 1", null);
try {
if (cursor.moveToNext()) {
//Record exists
} else {
//Record doesn't exists
}
} finally {
cursor.close();
}
My version:
public boolean isTitleExists(String title, String type) {
int isExists = 0;
try {
String query = "SELECT EXISTS (SELECT 1 FROM titles WHERE title = ? and type = ?)";
PreparedStatement statement = connection.prepareStatement(query);
statement.setString(1, title);
statement.setString(2, type);
ResultSet rs = statement.executeQuery();
rs.next();
isExists = rs.getInt(1);
rs.close();
statement.close();
} catch (SQLException e) {
Common.console("isTitleExists error: " + e.getMessage());
}
return isExists == 1;
}
I built a table in the database, and now I want to access the all of the values in a certain column. Finally, I want to put the data into byte[].
Part of my code:
db.execSQL("create table thing(id integer primary key" +
" autoincrement, name varchar(20))");
List<Integer> all = new ArrayList<Integer>();
String sql = " SELECT id from " + DB_NAME;
Cursor result = this.db.rawQuery(sql, null);
for (result.moveToFirst(); result.isAfterLast(); result.moveToNext()) {
all.add(result.getInt(0));
}
String[] fstr = (String[]) all.toArray();
for (String bstr : fstr) {
byte[] bbs = bstr.getBytes();
}
Use this code
String[] fstr = new String[result.getCount()] ;
do {
int posi = result.getPosition();
fstr[posi] =result.getString(0);
}while (result.moveToNext());
try this
Cursor c=this.db.rawQuery(sql, null);
if(c.getCount()>0)
{
for(c.moveToFirst();!c.isAfterLast();c.moveToNext())
{
String str=c.getInt(0));// or c.getString();
}
}
else
{
Log.d(" Null value in cursor ", " null ");
}
c.close();
dbhelper.close();
I have a simple code that manages to successfully query an SQLite Database and convert that result from cursor to string in order to display it on screen.
My problem now would be invalid queries that make the App Crash. Would there be a way to successfully handle invalid queries? Preferably something that would keep my app from crashing and would just redirect the user to the home page and display a toast of warning.
So far my method for searching looks like this:
public String search(DataBaseHelper myDB){
SQLiteDatabase db = myDB.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT BuildingColor, Room FROM LSBuildingsDB WHERE _id =" + newString, null);
cursor.moveToFirst();
String data = cursor.getString(cursor.getColumnIndexOrThrow("BuildingColor")) + " " +
cursor.getString(cursor.getColumnIndex("Room"));
//Toast msg = Toast.makeText(getBaseContext(),data, Toast.LENGTH_SHORT);
//msg.show();
cursor.close();
return data;
}
Cursor cursor = NULL ;
try
{
cursor = db.rawQuery("SELECT BuildingColor, Room FROM LSBuildingsDB WHERE _id =" + newString, null);
if(cursor != NULL)
{
try {
if (cursor.moveToNext()) {
String data = cursor.getString(cursor.getColumnIndexOrThrow("BuildingColor")) +
" " + cursor.getString(cursor.getColumnIndex("Room"));
} else {
// Query result was empty, deal with it here.
}
} finally {
// Cursors should be closed
cursor.close();
}
}
}
catch (SQLiteException e) // (Exception e) catch-all:s are bad mmkay.
{
//print exception
}
Cursor cursor = null;
String data = "";
try
{
cursor = db.rawQuery("SELECT BuildingColor, Room FROM LSBuildingsDB WHERE _id =" + newString, null);
}catch (Exception e) {
// TODO: handle exception
}