Cursor is used to retrieve data from an SQLite database. It points to a single row of results from a query and allows accessing and iterating through the records. ContentValues is a map-like class that matches values to string keys and is used to insert or update records in a content provider, which manages access to centralized application data through methods like query, insert, update, and delete.

1. Cursor & Content Value

2. Cursor
● Cursor is used to Retrieving the data from SQLite Database
● The basic purpose of a cursor is to point to a single row of the result fetched by the query.
● We load the row pointed by the cursor object.
● By using cursor we can save lot of ram and memory.
● Cursor is the Interface which represents a 2 dimensional table of any database.
● When you try to retrieve some data using SELECT statement, then the database will first create a
CURSOR object and return its reference to you.
● To use Cursors android.database. Cursor must be imported.
● Cursors store query result records in rows and grant many methods to access and iterate through the
records.
● Cursors should be closed when no longer used, and will be deactivated with a call to Cursor.deactivate()
when the application pauses or exists.
● On resume the Cursor.requery statement is executed to re-enable the Cursor with fresh data.
● These functions can be managed by the parent Activity by calling startManagingCursor().

3. Public Methods Cursor
abstract
void
close() Closes the Cursor, releasing all of its resources and
making it completely invalid.
abstract
void
copyStringToBuffer(int
columnIndex,
CharArrayBuffer buffer)
Retrieves the requested column text and stores it in the
buffer provided.
abstract int getColumnCount() Return total number of columns
abstract int getColumnIndex(String
columnName)
Returns the zero-based index for the given column name,
or -1 if the column doesn't exist.
abstract int getColumnIndexOrThrow(St
ring columnName)
Returns the zero-based index for the given column name,
or throws IllegalArgumentException if the column doesn't
exist.
abstract
String
getColumnName(int
columnIndex)
Returns the column name at the given zero-based column
index.

4. abstract
String[]
getColumnNames() Returns a string array holding the names of all of the
columns in the result set in the order in which they were
listed in the result.
abstract int getCount() Returns the numbers of rows in the cursor.
abstract
double
getDouble(int columnIndex) Returns the value of the requested column as a double.
abstract
Bundle
getExtras() Returns a bundle of extra values.
abstract
float
getFloat(int columnIndex) Returns the value of the requested column as a float.

5. abstract
Bundle
getExtras() Returns a bundle of extra values.
abstract
float
getFloat(int columnIndex) Returns the value of the requested column as a float.
abstract int getInt(int columnIndex) Returns the value of the requested column as an int.
abstract
long
getLong(int columnIndex) Returns the value of the requested column as a long.
abstract int getPosition() Returns the current position of the cursor in the row set.
abstract
short
getShort(int columnIndex) Returns the value of the requested column as a short.
abstract
String
getString(int columnIndex) Returns the value of the requested column as a String.

6. Public Methods
abstract int getType(int
columnIndex)
Returns data type of the given column's value.
abstract
boolean
isAfterLast() Returns whether the cursor is pointing to the position after the last
row.
abstract
boolean
isBeforeFirst() Returns whether the cursor is pointing to the position before the
first row.
abstract
boolean
isClosed() return true if the cursor is closed
abstract
boolean
isFirst() Returns whether the cursor is pointing to the first row.
abstract
boolean
isLast() Returns whether the cursor is pointing to the last row.

7. abstract
boolean
isNull(int
columnIndex)
Returns true if the value in the indicated column is null.
abstract
boolean
move(int offset) Move the cursor by a relative amount, forward or backward, from
the current position.
abstract
boolean
moveToFirst() Move the cursor to the first row.
abstract
boolean
moveToLast() Move the cursor to the last row.
abstract
boolean
moveToNext() Move the cursor to the next row.
abstract
boolean
moveToPosition(int
position)
Move the cursor to an absolute position.
abstract
boolean
moveToPrevious() Move the cursor to the previous row.

8. ● ContentValues is a maplike class that matches a value to a String key
● A content provider manages access to a central repository of data.
● A provider is part of an Android application, which often provides its own UI for working with the data.
● However, content providers are primarily intended to be used by other applications, which access the provider using a
provider client object.
. public final class ContentValues extends Object implements Parcelable
Content Values

9. Create Database
- Create Table
- Provide data in row formate
- Abc, xyz,pqr

10. ContentProvider
● onCreate() This method is called when the provider is started.
● query() This method receives a request from a client. The result is returned as a Cursor object.
● insert()This method inserts a new record into the content provider.
● delete() This method deletes an existing record from the content provider.
● update() This method updates an existing record from the content provider.
● getType() This method returns the MIME type of the data at the given URI.

11. CRUD is nothing but an abbreviation for the basic operations that we perform in any database. And
the operations are
● Create
● Read
● Update
● Delete
CRUD

12. CREATE TABLE employees (
id INTEGER NOT NULL CONSTRAINT employees_pk PRIMARY KEY AUTOINCREMENT,
name varchar(200) NOT NULL,
department varchar(200) NOT NULL,
joiningdate datetime NOT NULL,
salary double NOT NULL
);
Create Table
INSERT INTO employees
(name, department, joiningdate, salary)
VALUES
('Belal Khan', 'Technical', '2017-09-30 10:00:00', '40000');
Creating a new Record

13. UPDATE employees
SET
name = 'Belal Haque',
department = 'Research and Development',
salary = '100000'
WHERE id = 1;
Updating Data