Start learning with our library of video tutorials taught by experts. Get started

Java Database Integration with JDBC

Getting the DatabaseMetaData object


From:

Java Database Integration with JDBC

with David Gassner

Video: Getting the DatabaseMetaData object

In most database application environments, you already know the database structure, the names of the tables, the number, and types of the columns, and so on, but there are times when you have to discover this information dynamically, and JDBC gives you that ability through a function called metadata. The term metadata in the context of databases describes exactly the sort of information, and you can get the metadata from a database connection quite easily. I'll do an initial demonstration of this functionality in a project named Table List.
Expand all | Collapse all
  1. 5m 23s
    1. Welcome
      53s
    2. What you should know before starting this course
      1m 20s
    3. Using the exercise files
      3m 10s
  2. 12m 2s
    1. Testing your Java development environment
      5m 14s
    2. Importing a MySQL database
      5m 1s
    3. Creating a database user in MySQL
      1m 47s
  3. 32m 47s
    1. What is JDBC?
      4m 26s
    2. Choosing a JDBC driver
      6m 46s
    3. Connecting to a MySQL database server
      8m 7s
    4. Connecting to a HyperSQL database file
      6m 23s
    5. Executing a static SQL statement
      7m 5s
  4. 17m 42s
    1. Connecting to multiple databases
      6m 24s
    2. Handling JDBC exceptions
      7m 7s
    3. Closing database resources in Java 7
      4m 11s
  5. 47m 25s
    1. Looping through result sets
      8m 23s
    2. Moving the cursor in scrollable result sets
      5m 51s
    3. Limiting the number of fetched rows
      6m 57s
    4. Filtering data with prepared statements
      6m 58s
    5. Calling stored procedures
      5m 48s
    6. Handling multiple values from stored procedures
      5m 54s
    7. Using generic getter methods in Java SE 7
      7m 34s
  6. 45m 23s
    1. Managing data entities with JavaBean classes
      5m 0s
    2. Retrieving a single row as a JavaBean object
      6m 5s
    3. Inserting rows with prepared statements
      8m 2s
    4. Updating rows with prepared statements
      5m 4s
    5. Deleting rows with prepared statements
      4m 9s
    6. Managing data with updatable result sets
      6m 6s
    7. Using a persistent database connection
      6m 43s
    8. Committing and rolling back transactions
      4m 14s
  7. 9m 35s
    1. Getting the DatabaseMetaData object
      3m 40s
    2. Getting column and data type information
      5m 55s
  8. 50s
    1. Next steps
      50s

Watch this entire course now—plus get access to every course in the library. Each course includes high-quality videos taught by expert instructors.

Become a member
Please wait...
Java Database Integration with JDBC
2h 51m Intermediate Nov 28, 2012

Viewers: in countries Watching now:

Whether you're building a web- or desktop-based application with Java SE or Java EE, many Java applications need to integrate data from a relational database. This course describes how to read and manage data from relational databases such as MySQL and SQL Server using the Java Database Connectivity (JDBC) API.

Author David Gassner explains how to choose a JDBC driver and connect to one or more databases. He also provides detailed instructions on reading, selecting, and updating data; calling stored procedures; managing data via JavaBean classes or with prepared statements; and working with metadata.

Topics include:
  • Importing a MySQL database
  • Connecting to databases
  • Handling JDBC exceptions
  • Looping through result sets
  • Limiting the number of fetched rows
  • Filtering data with prepared statements
  • Calling stored procedures
  • Inserting, updating, and deleting rows with prepared statements
  • Using a persistent database connection
  • Committing and rolling back transactions
Subjects:
Developer Databases Programming Languages
Software:
Java
Author:
David Gassner

Getting the DatabaseMetaData object

In most database application environments, you already know the database structure, the names of the tables, the number, and types of the columns, and so on, but there are times when you have to discover this information dynamically, and JDBC gives you that ability through a function called metadata. The term metadata in the context of databases describes exactly the sort of information, and you can get the metadata from a database connection quite easily. I'll do an initial demonstration of this functionality in a project named Table List.

I'm using a Singleton Connection Manager which I have described how to build in a previous exercise. I have gotten a reference to my connection, and then within the try catch block, I'm going to add some data to get a list of tables that's in my database. Within the try block, I'll first declare an object instantiated as DatabaseMetaData. As with many other objects in JDBC, you might see more than one version. Always be sure to choose the version from java.sql for maximum portability. I'll name this object metadata.

Then I'll get its reference from the connection object's getMetaData method. You'll see a couple of versions listed, but in fact, there is only one. The getMetaData method takes no arguments. I'm going to interrogate this object to get a list of tables. There are actually many different types of tables in a database. But the only ones I'm interested in are the ones that contain my data. And there's a series of database types that I can select from. To control which database table names are returned, I'm going to create an array of strings, and I'll name it tableTypes, and I'll declare the array as a pair of braces, and I will only have it contain one item.

All database management systems should support this table type, but the number and names of the different table types will then vary from one database management system to the next. Now, I'm going to get the list of tables. It's going to come back as a result set. I'm going to name the result set RS Tables, and to properly manage it, first I will declare the result set outside of the try catch block. I'll declare it with a data type of ResultSet, then rsTables as the object name, and I'll initially set it to null.

Then within the try block, I'll instantiate it with rsTables=metadata.getTables. The getTables method takes four arguments, the catalog which is the name of the database which I have already selected in my connection string, so I don't need to pass it in again. I'll set that to null, the schemaPattern which I'll set as a wildcard of a percent sign, the tableNamePattern which I'll also set with a percent sign wildcard, and the tableTypes which will be my array of strings that I already created.

The result set will come back with a column named table_name. So now, to print out the list of tables, I'll create a while loop, and I will iterate with a condition. The condition will be rsTables.next. So I am going to be moving forward through the ResultSet and working with each row one at a time. Then within the while loop, I'll use system output, and I'll output the value of rsTables.getString, and I'll pass in the name of the column TABLE_NAME. When I'm done, I'll need to close the result set.

As with all result sets, you will typically do this in a finally block. So I'll move the cursor there and call rsTables.close. I'll save my changes and run the code, and there is my list of tables in my backend database. You're able to do a lot more than this with the database metadata, including finding out about columns, their names, and their datatypes. I'll show you how to do some of these other tasks in another video.

There are currently no FAQs about Java Database Integration with JDBC.

Share a link to this course
Please wait... Please wait...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.
Upgrade now


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ.

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

join now

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed Java Database Integration with JDBC.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferencesfrom the dropdown menu.

Continue to classic layout Stay on new layout
Welcome to the redesigned course page.

We’ve moved some things around, and now you can



Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked