Troubleshooting

This section lists possible problems in working with the tutorial application. If you are not getting the results that you expect, here are some things you can try to fix the problem.

About this task

Make sure that your EGL code has no validation or generation errors, marked by red X icons in the code editor or by errors in the EGL Generation Results view. If a source file is listed in the EGL Generation Results view with a red X icon rather than a green check mark icon, it did not generate properly. Most of the EGL code used in this tutorial is included at the end for your reference; see Resources.
Make sure all of your files are saved and then generate the entire project by right-clicking the project and then clicking Generate.
Make sure that you have followed all of the steps in Lesson 1: Set up the database connection, including:
- Set all the build descriptor options by opening the build descriptor for the project and selecting your database connection in the Load DB options using Connection list. Save and generate the project after making any changes to the build descriptor.
- Add the Derby JAR file to the Java™ build path for the project.
Check that the database connection is correct:
1. Click Window > Preferences.
2. In the Preferences window, expand EGL and click SQL Database Connections.
3. In the Connection list, select your connection, which is usually named EGLDerbyR7, unless you have already created a connection to the sample database (such as in the tutorial Introducing EGL (a quick-start guide)), in which case the connection is named EGLDerbyR71.
4. Make sure that the properties for that connection match the locations of the relevant files on your computer. Your connection should look like this, with your own locations for the derby.jar file and the EGLDerbyR7 folder (which contains the database):
5. If the properties don't match the actual locations of the files, click Edit, correct the settings, and click Test Connection to ensure that the connection works.

Check that the data parts and logic parts have been created correctly:

Make sure that you have all of the files in the eglderbyr7 package, as in this picture:

As an example, open the Customer.egl file in the eglderbyr7.data package and compare the Customer Record part to the following record:

record Customer type sqlRecord { 
        tablenames=[["EGL.CUSTOMER"]],
        keyItems=[CustomerId]
    } 

  CustomerId CustomerId {column="EGL.CUSTOMER.CUSTOMER_ID"};
  FirstName FirstName {column="EGL.CUSTOMER.FIRST_NAME", 
    sqlVariableLen=yes, maxLen=30, isSqlNullable=yes};
  LastName LastName {column="EGL.CUSTOMER.LAST_NAME", 
    sqlVariableLen=yes, maxLen=30, isSqlNullable=yes};
  Password Password {column="EGL.CUSTOMER.PASSWORD", 
    maxLen=8, isSqlNullable=yes};
  Phone Phone {column="EGL.CUSTOMER.PHONE", 
    sqlVariableLen=yes, maxLen=14, isSqlNullable=yes};
  EmailAddress EmailAddress {column="EGL.CUSTOMER.EMAIL_ADDRESS", 
    sqlVariableLen=yes, maxLen=50, isSqlNullable=yes};
  Street Street {column="EGL.CUSTOMER.STREET", 
    sqlVariableLen=yes, maxLen=30, isSqlNullable=yes};
  Apartment Apartment {column="EGL.CUSTOMER.APARTMENT", 
    sqlVariableLen=yes, maxLen=10, isSqlNullable=yes};
  City City {column="EGL.CUSTOMER.CITY", sqlVariableLen=yes, 
    maxLen=30, isSqlNullable=yes};
  State State {column="EGL.CUSTOMER.\"STATE\"", maxLen=2, 
    isSqlNullable=yes};
  Postalcode Postalcode {column="EGL.CUSTOMER.POSTALCODE", 
    sqlVariableLen=yes, maxLen=10, isSqlNullable=yes};
  Directions Directions {column="EGL.CUSTOMER.DIRECTIONS", 
    sqlVariableLen=yes, maxLen=255, isSqlNullable=yes};
end

If your parts aren't correct, step through the EGL Data Access Application wizard again carefully to recreate them and overwrite the incorrect ones. For example, if the tableNames property on your Record parts and the column property on the fields within those Record parts do not include the EGL. prefix to each table name, you forgot to select the Qualify table names with schema check box.

Runtime error messages

This a list of some error messages that you may see in the Console view while trying to run the programs in this tutorial.

EGL0505E Cannot connect to jdbc:derby:C:\databases\EGLDerbyR7;create=true: Failed to start database 'C:\databases\EGLDerbyR7', see the next exception for details.: The data tools that create parts based on the database are still connected to the database, preventing the EGL program from connecting. Close the data tools connection in the Database Explorer view and then try running the EGL program again, as explained in Running a test program.
EGL0507E An error occurred while loading the JDBC drivers. Error: egl.core.RuntimeException: EGL0009E A value for the vgj.jdbc.drivers property is required.: The build descriptor is not set correctly. Load values for the build descriptor options by opening the build descriptor and selecting your connection in the Load DB options using Connection list.
EGL0507E An error occurred while loading the JDBC drivers. Error: java.lang.ClassNotFoundException: org.apache.derby.jdbc.EmbeddedDriver: EGL cannot find the derby.jar file. Make sure you have added the file to the project's Java build path as explained in Importing and connecting to the database.

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