This is what i am using for insert:
public long insert(String content, Date startAt, Date endAt) {
if (content == null || startAt == null) {
return 0;
}
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_CONTENT, content);
contentValues.put(KEY_START_AT, startAt.getTime());
if (endAt == null) {
contentValues.putNull(KEY_END_AT);
} else {
contentValues.put(KEY_END_AT, endAt.getTime());
}
return sqLiteDatabase.insert(TABLE_NAME, null, contentValues);
}
now i want to create update method which will update last inserted row. How can i get last inserted row?
If you have an id attribute that works as a primary key, you can do a raw database query on SqlLite.
Cursor cc = this.mDb.rawQuery("SELECT *" + " FROM " + "<Your DATABASE_NAME> " +
"ORDER BY id " + "DESC LIMIT 1", null);
return cc;
Here,
1. It returns a cursor.
2. mDb is a SQLiteDatabase class instance.
3. ORDER BY id allows the query to sort by id number. As I said, if you have an id as primary key in your table, your latest entry will have the maximum id number.
4. DESC allows to sort by descending order.
5. LIMIT 1 allows to return only 1 row.
6. Always be careful when writing raw queries, white spaces inside the query can be a lot of pain when you do not handle them carefully.
For further queries you can see this tutorial. And obviously Divya's answer is also a good one.
You can use a cursor to retrieve rows and say :
cursor.moveToLast();
OR
cursor.moveToPosition(cursor.getCount() - 1);
When you insert a row in to your table the insert query returns the key of the last inserted row. You can now use this key to update this row.
for example
int newInsertedKey = sqLiteDatabase.insert(TABLE_NAME, null, contentValues);
update table_name set column_name = 'Change 2' where columnID = newInsertedKey
An efficient method would be to avoid anymore database queries to get the last updated row.
Maybe he should use something like this
public long getLastId() {
Cursor c = mDb.query(currentTableName, new String[] { "MAX(_id)" },
null, null, null, null, null, null);
try{
c.moveToFirst();
long id = c.getLong(0);
return id;
}catch(Exception e){
return 0;
}
}
where _id is column by which you identify rows
Related
How should i get most recent added record from database, where COL_2 should == param that I pass into it.
I can get all records where COL_2 is equal to param with this code, but I need only recent one
public Cursor getRowsLast(String param) {
SQLiteDatabase db = helper.getWritableDatabase();
String[] COLS = new String[]{DatabaseHelper.COL_1,DatabaseHelper.COL_2, DatabaseHelper.COL_3,DatabaseHelper.COL_4};
String where = param;
Cursor c = db.query(true, DatabaseHelper.TABLE_NAME, COLS, DatabaseHelper.COL_2 + " = '" + where + "'", null, null, null, null, null);
if(c != null){
c.moveToFirst();
}
return c;
}
The most reliable way to get the most recent row in a table is to have a column defined in the table for the time of insert/update. Make sure this value is accurate at the time of insert/update, and create an index on it. You can then sort (descending) on this column to determine which one is the most recent - it will be the first row.
As the automatically generated ID values increase with every insert, the row with the highest ID will be the one that was inserted most recently. So add an 'order by _id desc' and the first row will be the most recently inserted one.
Note - this does not cover updates. If you need the row most recently inserted or updated, you'll have to use an additional timestamp column like Doug Stevenson suggested.
Hy Guys, I am Beginner Android Developer. I need your help. i want to insert data into 2 tables of sqlite tblorder, and orderdtl. on orderdtl i have to insert data from multiple item from listview. i try to toast all variable that i want to inserted. their all appears. but when i try to save it. i get those error.
this is my DBDataSource.java
public order createorder(String orderid, String notes, long outletid) {
ContentValues values = new ContentValues();
values.put(DBHelper.ORDER_ID, orderid); // inserting a string
values.put(DBHelper.NOTES, notes); // inserting an int
values.put(DBHelper.OUTLET_ID, outletid); // inserting an int
long insertId = database.insert(DBHelper.TABLE_ORDER, null,
values);
Cursor cursor = database.query(DBHelper.TABLE_ORDER,
allorder, DBHelper.ORDER_ID + " = " + insertId, null,
null, null, null);
cursor.moveToFirst();
order neworder = cursorToorder(cursor);
cursor.close();
return neworder;}
private order cursorToorder(Cursor cursor) {
order order = new order();
order.setorderid(cursor.getString(cursor.getColumnIndex(DBHelper.ORDER_ID)));
order.setorderdate(cursor.getString(cursor.getColumnIndex(DBHelper.ORDER_DATE)));
order.setnotes(cursor.getString(cursor.getColumnIndex(DBHelper.NOTES)));
order.setoutletid(cursor.getLong(cursor.getColumnIndex(DBHelper.OUTLET_ID)));
return order;
}
The error refer to this code
Cursor cursor = database.query(DBHelper.TABLE_ORDER,
allorder, DBHelper.ORDER_ID + " = " + insertId, null,
null, null, null);
And this code
order.setorderid(cursor.getString(cursor.getColumnIndex(DBHelper.ORDER_ID)));
orderid is string, i try to get from yyyyMMddHHmmss.this is the code:
private String orderid(){
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyyMMddHHmmss", Locale.getDefault());
Date date = new Date();
return dateFormat.format(date);
}
I would be very grateful for any help that you give.Thank You.
The query didn't match any rows. Check the result of moveToFirst() to see whether the operation succeeded and only then access cursor data.
Example:
order neworder = null;
if (cursor.moveToFirst()) {
order neworder = cursorToorder(cursor);
}
cursor.close();
return neworder;
The insertId you get from insert() is the sqlite row id for the row. It's likely not the same as ORDER_ID. To make a column an alias for rowid, declare it as INTEGER PRIMARY KEY.
The error I see in logcat is not about _Player_8, but about the unknown column "KEY_Team_Name"
The problem is in your activity, the line prior to the last one:
String EntryA =String.valueOf( db.getentry("Ravirrrr", "KEY_Team_Name"));
It should be:
String EntryA =String.valueOf( db.getentry("Ravirrrr", DatabaseHandler.KEY_Team_Name));
And the DatabaseHandler should have all column names public, as the getentry method requires a column name.
Edit: adding an answer to the question in the comments below.
After calling db.query, you should check if you got something by calling Cursor.isAfterLast(). If true, the select returned an empty result set.
In your example, you WILL get an empty result set as the code creates an entry with "Ravi" as the team name, then asks for a team named "Ravirrrr".
Inserting data to SQLite table with constraint failure
I'm trying to insert data into SQLite table on Android. _id is primary key of the table and I am inserting a row using this method:
public void addSomeData(int id, String datetime) {
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_ID, id);
contentValues.put(KEY_DATETIME, datetime);
mDb.insert(TABLE, null, contentValues);
}
The problem I get is that sometimes primary key constraint is validated and I would like to use something like INSERT IF NOT EXISTS, but preferably something that would work with ContentValues. What are my options? I understand that insertOrThrow() and insertWithOnConflict() methods only return different values, or should I use one of these methods?
Use insertWithOnConflict() with CONFLICT_IGNORE.
Will return ROWID/primary key of new or existing row, -1 on any error.
In my case "constraint failure" happened because of I had some tables which are depended on each other. As for the "insert if not exist", you can query with this id and you check if the cursor's count is bigger than zero. Check the method I'm already using in my app.
public boolean isRowExists(long rowId) {
Cursor cursor = database.query(this.tableName, this.columns, DBSQLiteHelper.COLUMN_ID + " = ? ", new String[] { "" + rowId }, null, null, null);
int numOfRows = cursor.getCount();
cursor.close();
return (numOfRows > 0) ? true : false;
}
to do so you could simply query the db to see if a row with that key exists and insert the new row only if the query returns no data.
Before inserting a record in the database to validate that there is, for example I have a table that has two fields, table fields VA with Customer, First, I want to validate the field if there is no customer registration and if there insert
That i want to do in android using Sqlite
String sql = "SELECT * FROM TABLE WHERE id = '" + id + "'";
Cursor data = database.rawQuery(sql, null);
After this check by following code
if (cursor.moveToFirst()) {
// record exists
} else {
// record not found
}
Look at SQLite constraints. This really isn't Android-specific; it's a feature of SQLite.
Try this, it works for me.
String[] args = { myDataToCheck };
c = ourDatabase.query(DATABASE_TABLE, columns,
myColumnToCheck + "=?", args, null, null, null);
if (c.getCount() == 0) {
// doesn't exists
}else{
//exists
}
You have 2 possibilities :
1)make a select to check if there is the same key in database, then insert or update.
2)make directly an update. update will return the number of row updated, if the number is 0, so you can do an insert.
Using the typical SQLiteDatabase object in Android's API, what can I do to get the next AUTO_INCREMENT value of a particular column (ie. id) without affecting the value itself. Is there a method for that? Or what query should I execute to get that result. Keep in mind that SQLiteDatabase.query() returns a Cursor object, so I'm not too sure how to deal with that directly if I just want to get a value out of it.
You're right. The first answer (still below) only works without an AUTOINCREMENT for id. With AUTOINCREMENT, the values are stored in a separate table and used for the increment. Here's an example of finding the value:
public void printAutoIncrements(){
String query = "SELECT * FROM SQLITE_SEQUENCE";
Cursor cursor = mDb.rawQuery(query, null);
if (cursor.moveToFirst()){
do{
System.out.println("tableName: " +cursor.getString(cursor.getColumnIndex("name")));
System.out.println("autoInc: " + cursor.getString(cursor.getColumnIndex("seq")));
}while (cursor.moveToNext());
}
cursor.close();
}
See: http://www.sqlite.org/autoinc.html
First Answer:
You can query for the max of the _id column, such as:
String query = "SELECT MAX(id) AS max_id FROM mytable";
Cursor cursor = db.rawQuery(query, null);
int id = 0;
if (cursor.moveToFirst())
{
do
{
id = cursor.getInt(0);
} while(cursor.moveToNext());
}
return id;
This works for row ids that haven't been specified as "INTEGER PRIMARY KEY AUTOINCREMENT" (all tables have a row id column).
This is the best way to get the last ID on auto increment PRIMARY KEY with SQLITE
String query = "select seq from sqlite_sequence WHERE name = 'Table_Name'"
An important remark about the SQLITE_SEQUENCE table.
The documentation says
The SQLITE_SEQUENCE table is created and initialized automatically whenever a normal table that contains an AUTOINCREMENT column is created.
So the SQLITE_SEQUENCE table is created, but NOT the row associated with the table that contains the AUTOINCREMENT column. That row is created with the first insert query (with "seq" value of 1).
That means that you must doing at least one insert operation before looking for the next autoincrement value of a specific table. It could be done for example just after the creation of the table, performing an insert and a delete of a dummy row.
Here is what I use to get the next AUTOINCREMENT value for a specific table:
/**
* Query sqlite_sequence table and search for the AUTOINCREMENT value for <code>tableName</code>
* #param tableName The table name with which the AUTOINCREMENT value is associated.
*
* #return The next AUTOINCREMENT value for <code>tableName</code>
* If an INSERT call was not previously executed on <code>tableName</code>, the value 1 will
* be returned. Otherwise, the returned value will be the next AUTOINCREMENT.
*/
private long getNextAutoIncrement(String tableName) {
/*
* From the docs:
* SQLite keeps track of the largest ROWID using an internal table named "sqlite_sequence".
* The sqlite_sequence table is created and initialized automatically
* whenever a normal table that contains an AUTOINCREMENT column is created.
*/
String sqliteSequenceTableName = "sqlite_sequence";
/*
* Relevant columns to retrieve from <code>sqliteSequenceTableName</code>
*/
String[] columns = {"seq"};
String selection = "name=?";
String[] selectionArgs = { tableName };
Cursor cursor = mWritableDB.query(sqliteSequenceTableName,
columns, selection, selectionArgs, null, null, null);
long autoIncrement = 0;
if (cursor.moveToFirst()) {
int indexSeq = cursor.getColumnIndex(columns[0]);
autoIncrement = cursor.getLong(indexSeq);
}
cursor.close();
return autoIncrement + 1;
}
Inside the SQLiteOpenHelper you use, start a transaction. Insert some data and then rollback.
Such a way, you 'll be able to get the next row id, like this:
public long nextId() {
long rowId = -1;
SQLiteDatabase db = getWritableDatabase();
db.beginTransaction();
try {
ContentValues values = new ContentValues();
// fill values ...
// insert a valid row into your table
rowId = db.insert(TABLE_NAME, null, values);
// NOTE: we don't call db.setTransactionSuccessful()
// so as to rollback and cancel the last changes
} finally {
db.endTransaction();
}
return rowId;
}
It's work.
public static long getNextId(SQLiteDatabase db, String tableName) {
Cursor c = null;
long seq = 0;
try {
String sql = "select seq from sqlite_sequence where name=?";
c = db.rawQuery(sql, new String[] {tableName});
if (c.moveToFirst()) {
seq = c.getLong(0);
}
} finally {
if (c != null) {
c.close();
}
}
return seq + 1;
}
You can use cursor.getInt(i); method
i here is index of the id column
Cursor c = db.rawQuery("Select * From mSignUp", null);
String mail = null;
try {
while (c.moveToNext()) {
mail = c.getString(0);
String pas = c.getString(1);
Toast.makeText(getApplicationContext(), "Name = " + mail + " Pass = " + pas, Toast.LENGTH_SHORT).show();
}
}catch (CursorIndexOutOfBoundsException e){
Log.e("OutOfBound", Log.getStackTraceString(e));
}
finally {
c.close();
}