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Mastering Spool Command: Export Query Results in Oracle Databases

Spool is a command used in SQL*Plus clients to output the query results to different file types. It is one of the most useful and convenient tools for data manipulation in the Oracle database.

This article will discuss Spool and its two primary modes of exporting- CSV and text file. We will also explore how to modify Spool to change the file type from CSV to a text file.

Exporting to CSV File using Spool

CSV or comma-separated values is a file format used for storing data in which each value is separated by a comma. It is a useful format for exchanging data between different applications.

One of the significant benefits of exporting Oracle query results to a CSV file is its portability. The file can be opened in spreadsheet applications, such as Microsoft Excel and Google Sheets, or loaded into databases, such as MySQL.

To export query results to a CSV file using Spool, follow these steps:

  1. Open SQL*Plus and enter the query you want to export.
  2. Execute the Spool command followed by a directory path and file name with a .csv extension.

The command should look like this:

SQL> Spool C:Exportquery_result.csv;

Step 3: Execute the query command, and the results will be saved in a CSV file.

Exporting to Text File using Spool

Exporting query results to a text file using Spool is essential for plain text data. Unlike CSV file, which separates values with commas, text files store data in a human-readable format.

Text files are compatible with many applications and are a preferred format for data export, especially when sharing data between different software. Spool command can be modified to export query results to text files.

To export query results to a text file, use the following steps:

  1. Open SQL*Plus and type the query you want to export.
  2. Change the separator of the Spool command from a comma (,) to a space ( ):
    3. SQL> set colsep ' ';
  3. Execute the Spool command followed by a directory path and file name with a .txt extension:
    4. SQL> Spool C:Exportquery_result.txt;
  4. Run the query command.

The results will be saved in the text file you specified.

Modifying Spool for Exporting Query Results to Text File

To modify the Spool command to export to a text file, you need to change the file separator from a comma to a space. This modification is necessary because text files don’t have a default delimiter like CSV files.

To export to a text file using Spool, implement the following steps:

  1. Open SQL*Plus and connect to the database.
  2. Type the query you want to export and include a separator in each column with a space.
    3. SELECT FIRST_NAME || ' ' || LAST_NAME || ' ' || SALARY FROM EMPLOYEES;
  3. Change the separator to a space by typing the following command before the Spool command:
    4. SQL> set colsep ' ';
  4. Execute the Spool command followed by the file path and name with a .txt extension. Here’s an example:
    5. SQL> Spool C:Exportemployee_salary.txt;
  5. Run the query, and the results will be saved in the text file.

Changing File Type from CSV to Text

To change the Spool file type from CSV to a text file, you need to modify the Spool command with file type extension. Follow these steps to change the file type:

  1. Type the Spool command and directory path, followed by the name of the file with the .txt extension.
    2. SQL> Spool C:Exportemployee_salary.txt;
  2. Include the SELECT command containing your query. 
    3. SQL> SELECT FIRST_NAME || ' ' || LAST_NAME || ' ' || SALARY FROM EMPLOYEES;
  3. Execute the query, and the results will be saved in the text file.

Conclusion

In conclusion, Spool command is a powerful tool for exporting query results to different file formats. It offers versatility and flexibility to database administrators and analysts to manipulate data.

CSV and text files are the two primary modes of exporting query results with Spool. Exporting query results in CSV format is suitable for data exchange between different tools and applications, while text files are useful for data export in a human-readable format.

Modifying Spool command is also possible, making it easier to change the file type from CSV to text.

3) Running Spool to Export Query Results

Spooling is the process of directing query results or log output to a file on disk instead of returning it to the screen. Running Spool is a great way for developers to export query results to different file formats, including CSV and text files.

In this section, we will discuss how to execute Spool as a script and generate a file at a specified path.

Executing Spool as a Script

Using Spool as a script allows users to run a series of commands simultaneously and automate repetitive tasks. Simply put, a script is a file containing a series of SQL commands that are executed when the script is run.

When Spool is executed as a script, the results of the query are spooled to a text file with the specified file name and directory path. To execute Spool as a script, follow these steps:

  1. Create a new file with a .sql extension.

    2. This file will contain the SQL commands to be executed.

  2. Add Spool and SELECT commands to the script file.

    3. Here’s an example:

    Spool c:exportemployee_salary.txt;
SELECT FIRST_NAME || ' ' || LAST_NAME || ' ' || SALARY from EMPLOYEES;
Spool off;

    Note that the Spool off command is used to stop spooling the output to the file.

  3. Save the file and execute it by running the SQL file.

    4. Here is an example of executing the script in SQL*Plus:

    SQL> @c:sql_scriptsemployee_salary.sql;
  4. Check the directory path to locate the file and open it to view the query results.

Generating File at Specified Path

When running Spool, users can specify the file name and path of the export file. The Spool command includes a file path parameter in which the file is generated.

When specifying the file path, be sure to use a valid path and include the correct file extension based on the file format required. To generate a file at a specified path, follow these steps:

  1. Open SQL*Plus and connect to the database.
  2. Enter the query you would like to export.
  3. Type the Spool command with the file name and path parameter.

    4. Here is an example:

    SQL> Spool C:reportsemployee_salary.csv;
  4. Execute the query command, and the results will be saved automatically in the specified file at the specified path.
  5. Run the Spool off command to stop Spooling the query results.

4)

Conclusion

In this article, we have discussed different ways to export query results using Spool command in SQL*Plus. Spooling is an essential tool in the database administrator or analyst’s toolkit as it enables efficient data management from the Oracle database.

We have learned about exporting query results to CSV and text files, modifying Spool command to change the file type and executing Spool as a script to automate repetitive tasks. Finally, we have seen how to generate files at a specified path by specifying the Spool command’s file path parameter.

This comprehensive guide on Spool command provides developers with an in-depth insight into the various aspects of Spooling query results. By following the recommended procedures outlined in this guide, developers can export query results quickly and efficiently not only to CSV and text files but other file formats as well.

Overall, the Spool command is an important feature in SQL*Plus that should not be overlooked by developers or database administrators using Oracle databases. This article provided a comprehensive guide on Spool command to export query results in Oracle databases.

The article covered various methods to utilize Spool, such as exporting results to CSV or text files, modifying Spool to change from CSV to text, executing Spool as a script, and generating files at a specified path. By following these methods, developers and database administrators can effectively manage data in the Oracle database.

Overall, Spool command is a powerful and versatile tool and is critical for data manipulation in SQL*Plus. This article emphasizes the importance of Spool command in managing data operations and encourages the readers to utilize it in their daily work routine for more efficient and effective data management.

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