3.18 Using Drag and Drop for Code Generation

The Drag-and-Drop Code Generation feature simplifies how various programming languages interact with Oracle databases. It enables you to drag and drop database objects into a Java file, which automatically generates the corresponding Java code, including all the logic required to execute queries on the Oracle database.

Additionally, you can drag an entire database connection from the Connections panel into your Java file to quickly generate the connection string or complete JDBC API code, streamlining your development process.

3.18.1 Generate Connection Code

When you drag a connection from the Connections panel and drop it into a Java file, the feature will automatically generate the necessary code for you. It supports all connection types including Basic, Custom JDBC, Cloud Wallet, and TNS ensuring flexibility for a wide range of Oracle database scenarios.

Perform the following steps to generate the connection code:

1. Open a SQL worksheet and set the language to Java, or open an existing Java file.
2. In the Connections panel, locate the desired database connection.
3. Drag the selected connection and drop it into your open Java file.

   A dialog box will appear prompting you to choose a code generation option.

4. Select any of the following code generation options:
   • Connection String: Generates the connection string for the dropped connection(s).
   • JDBC: Generates Java code that enables the user to connect to the dropped connection(s).
   The generated code (connection string or full JDBC API code) will automatically appear in your Java file.

   You can drag and drop multiple connections to automatically generate code for them at once.

The following examples illustrate a specific connection type configuration and the corresponding auto-generated JDBC code and the connection string after using the drag-and-drop feature. Here is a custom JDBC connection type without any advanced properties specified.

Description of the illustration code_generation_connection.png

For a selected connection type, such as Custom JDBC, if the code generation option is set to JDBC, the corresponding JDBC connection code is automatically generated. This code includes all the relevant details specified in the connection configuration, streamlining the process of connecting to the database.

Description of the illustration code_generation_output.png

If the code generation option selected is Connection String, only the connection string is displayed.

Description of the illustration code_generation_output_connectionstring.png

3.18.2 Generate Java Code for Database Objects

When you drag a database object, such as a table, view, duality view, materialized views, and columns from the Connections panel and drop it into a Java file, the feature will automatically generate the corresponding Java code. This includes all necessary logic required to execute queries on the Oracle database, streamlining the integration of database operations within your Java application.

Perform the following steps to generate Java code for database objects:

1. Open a SQL worksheet and set the language to Java, or open an existing Java file.
2. In the Connections panel, locate the desired database object.
3. Drag the selected database object and drop it into your open Java file.
   You can select and drag multiple database objects at once to generate comprehensive code for all selected items simultaneously.
4. Select the code generation option as JDBC.
5. Select the type of statement to be generated.
   The following options are available:

   • Object name: Generates the name of the object.
   • Insert:Generates Java code for inserting records into the object.
   • Delete: Generates Java code for deleting records from the object.
   • Update: Generates Java code for updating records in the object.
   • Select: Generates Java code for retrieving records from the object.
   • Drop: Generates Java code for removing (dropping) the database object.
   • Join: Generate Java code for queries that retrieve data by combining rows from two or more database objects based on related columns. This option is available only when you select multiple database objects.
6. Select columns from the selected object to be included in the generated SQL or Java code for operations, such as, SELECT, INSERT, UPDATE, DELETE, or JOIN, and then click OK.
   
   

   
   Description of the illustration code_generation_select_columns.png

   
   

The Java code for the selected database object is generated.

Example 3-1 Generating Java code for inserting data into a table

When you drag and drop the COUNTRIES table while selecting all the columns and choose the INSERT statement option, the following code is generated:

Description of the illustration code_generation_insert.png

This Java code snippet demonstrates that data is inserted into a database table named COUNTRIES using a PreparedStatement for safe and efficient database operations. This code inserts values into the COUNTRY_ID, COUNTRY_NAME, and REGION_ID columns. The question marks (?) are placeholders for the values that will be supplied later. The actual values for the placeholders are set using the .setString() and .setBigDecimal() methods.

Example 3-2 Generating Java code for retriving data spanning multiple related tables

When you drag and drop the COUNTRIES, DEPARTMENTS, and EMPLOYEES tables, select a few columns from each, and choose the JOIN statement option, the following code is generated:

Description of the illustration code_generation_join.png

Example 3-3 Generating Java code for multiple database objects simultaneously

When you drag and drop the COUNTRIES and DEPARTMENTS tables, select a few columns from each, and choose the DELETE statement option, delete code for each individual table is automatically generated. This code deletes records from multiple database tables (COUNTRIES and DEPARTMENTS) using parameterized SQL delete queries with JDBC’s PreparedStatement.

Description of the illustration code_generation_delete.png