Q) Give the list of accessibility modes in the increasing order of accessibility?

Accessibility modes from weakest to highest / increasing order

Private mode (weakest access privilege)

Default mode

Protected mode

Public mode (Highest access privilege

Comments

Q) What is JDBC driver? What is its role in java database connection?

A) ->A translation software written in java according o JDBC specification is nothing but “JDBC driver”. -> JDBC driver implements JDBC API. Use single API. JDBC driver role: They are 4 roles 1) Establishing connection between JDBC client and database server. 2) Receiving JDBC method calls made by JDBC client while performing database (CRUD) operations. 3) Translating java method calls into DBMS understandable calls and forwarding them to database server. 4) Receiving the results from database server. Translating them into java format and handling over the same to the JDBC client.

Q) Retrieving data from database?

A) ->to retrieve the data from database we need to submit SELECT statement from JDBC application. -> executeQuery() method of statement object is used for this purpose. This method has the fallowing ResultSet executeQuery(String sql) throws SQLException Ex: ResultSet rs = st.executeQuery(“SELECT * FROM ACCOUNT”); ->objectoriented representation of tables formate data is called ResultSet object. Ao the driver created one object i.e. ResultSet object. ->object orientation representation of a table of records returned from db is nothing but “ ResultSet ” object.

Q) What is ODBC?

A) ->open database connectivity is a technology from MS that enables any language program (other than java) to communication with database Management System. ->in java program ODBC is directly not allowed for the fallowing reasons 1) OS dependency 2) Procedural oriented approach 3) Security thread

స్వవిధ

Search This Blog