RDMBS MetaData

📘 RDBMS Metadata of HGrid247-3.5

RDBMS Metadata in HGrid247-3.5 is used for:

Selecting databases and tables in a RDBMS.
After selecting a table, the user can select the fields to be used in the query.
With this configuration, HGrid247 will automatically build Hive Query Statements without having to write them manually.

This feature is very helpful for HGrid247 integration with Hadoop/Hive data warehouse.

⚙️ RDBMS Metadata Configuration Parameters

JDBC Driver Class Name:
The fully qualified Java class name of the JDBC driver that tells Java which database driver to load.
URL Connection:
The connection string that tells the driver where to connect and how to connect.
User Name:
The user name authentication to connect the RDBMS server
Password:
The password authentication to connect the RDMBS server

🧪 Case Study

1. MySQL 8.0.40

    Parameter           Value
    -------------------------------------------------------
    JDBC Driver Class   com.mysql.cj.jdbc.Driver
    URL Connection      jdbc:mysql://localhost:3306/hgrid247
    User Name           root 
    Password            *******

The JDBC driver used

    mysql-connector-j-8.0.31.jar

Place this jar in:

    HGrid247-3.5/
        └── JDBCClient/

MySQL Metadata Viever

2. Postgres 42.7.7

Parameter Setting

    Parameter           Value
    ----------------------------------------------------------------------
    JDBC Driver Class   org.postgresql.Driver
    URL Connection      jdbc:postgresql://localhost:5432/postgres
    User Name           postgres
    Password            ********

The JDBC driver used

    postgresql-42.7.7.jar

Just like before, put this jar in the folder:

    HGrid247-3.5/
       └── JDBCClient/

Postgres Metadata Viever

📌 Required Folders for JDBC Driver

Make sure the JDBC driver is located at:

    HGrid247-3.5/
       └── JDBCClient/

If this folder does not exist or the jar is not found, then:

RDBMS Metadata cannot read database
Cannot load table
Cannot create automatic query

✅ If the connection is successful

A dialog box will appear showing:

Database successfully loaded
Table successfully retrieved
Fields can be selected
Queries can be created automatically