JDBC

• is an application programming interface (API) for the programming language Java.

• defines how the client can connect and interact with a Database.

JDBC Driver

💡

supports communication between the JDBC Manager and the Driver connection.

• Driver:

  • a software component

  • convert JDBC calls —middle layers—> native calls on DB server.
    • gives out the connection to the database
    • implements the protocol for transferring the query and result between client and database.

  • provided by a specific provider for a specific database.

  • JDBC’s 4 categories:

    • JDBC-ODBC bridge

    • Native-API driver

    • Network-Protocol driver

    • Native Protocol (Thin driver)

    

• DriverManager:

  • an interface between users and drivers.

  • maintains a list of drivers created for different databases

  • handles establishing a connection between a database and the appropriate driver.

JDBC API

💡

supports communication between the Java application and the JDBC manager.

• Java interfaces and classes that support connecting and manipulating with DBs.

• interfaces:
  • Connection

    • is used for creating the session between the application and the database.

    • contains Statement, PreparedStatement, and DatabaseMetaData.

    

  • Statement

    • is used for executing queries using the database.

    • Steps for interpreting a statement:
      1. Check syntax
      2. Load intro Mem
      3. Execute

    

    

  • PreparedStatement:

    • is a subinterface of Statement.

    • is mainly used for parameterized queries.
      • A question mark (?) is passed for the values.
      • The order of parameters is marked from 1.

    • Steps for interpreting:
      • First time: 1, 2, 3 like a super statement
      • Second time: only 3
  • CallableStatement

    • is used to call a stored procedure.

    • ….
  • ResultSet

    • used for maintaining the pointer to mapping data area from Database, a row of a table.
      • next(): forward only
      • always exist (≠null) after executing a SELECT statement (if empty date —> BOF & EOF is the same position)

    

  • ResultSetMetadata

    • is used to get metadata from the ResultSet object.

    

  • DatabaseMetadata

• Classes:
  • SQLException