Oracle SQL is a powerful tool for querying and manipulating data in a database. However, when it comes to formatting the output of a select statement, it can be a bit tricky. In this step-by-step guide, we will show you how to format Oracle SQL text-only select output to make it more readable and visually appealing.
Step 1: Use the SELECT statement
The first step in formatting Oracle SQL text-only select output is to use the SELECT statement. This statement is used to retrieve data from one or more tables in a database. It is the most commonly used statement in SQL and is key to formatting the output.
Step 2: Add column headers
By default, the output of a SELECT statement will not have column headers. To make the output more user-friendly, we recommend adding column headers. This can be done by using the AS keyword in the SELECT statement, followed by the desired column header name. For example:
SELECT employee_id AS "Employee ID", first_name AS "First Name", last_name AS "Last Name"
FROM employees;
Step 3: Use the TO_CHAR function
The TO_CHAR function in Oracle SQL is used to convert a value to a specific data type. In our case, we will use it to format the output of a date or number column. For example:
SELECT employee_id, first_name, TO_CHAR(hire_date, 'DD-MON-YYYY') AS "Hire Date", salary
FROM employees;
Step 4: Format numbers with the TO_CHAR function
To format numbers in the output, we can use the TO_CHAR function with the 'FM' format mask. This will remove any leading or trailing zeros from the number. For example:
SELECT employee_id, first_name, last_name, TO_CHAR(salary, 'FM999,999.99') AS "Salary"
FROM employees;
Step 5: Use the CONCAT function
If we want to combine multiple columns into one, we can use the CONCAT function. This function concatenates two or more strings together. For example:
SELECT CONCAT(first_name, ' ', last_name) AS "Full Name"
FROM employees;
Step 6: Add line breaks with the CHR function
To add line breaks in the output, we can use the CHR function. This function returns the character corresponding to the specified number. By using the CHR(10) function, we can add a line break after each row. For example:
SELECT employee_id, first_name || CHR(10) || last_name AS "Employee Name"
FROM employees;
Step 7: Use the LPAD function for alignment
The LPAD function is used to left-pad a string with a specified character. This can be useful for aligning columns in the output. For example:
SELECT employee_id, LPAD(first_name, 10) AS "First Name", LPAD(last_name, 10) AS "Last Name"
FROM employees;
Step 8: Use the ROUND function
If we want to round a decimal number in the output, we can use the ROUND function. This function rounds a number to the specified number of decimal places. For example:
SELECT employee_id, first_name, last_name, ROUND(salary, 2) AS "Salary"
FROM employees;
Step 9: Add a border with the LPAD function
To add a border to the output, we can use the LPAD function with a combination of dashes and pipes. For example:
SELECT LPAD('|', 5) || LPAD(employee_id, 10) || LPAD('|', 5) || LPAD(first_name, 15) || LPAD('|', 5) || LPAD(last_name, 15) || LPAD('|', 5) || LPAD(salary, 10) || LPAD('|', 5) AS "Employee Details"
FROM employees;
Step 10: Use the SPOOL command
Finally, if we want to save the formatted output to a file, we can use the SPOOL command. This command is used to log the output of a SQL statement to a file. For example:
SPOOL employee_details.txt
SELECT employee_id, first_name, last_name, salary
FROM employees;
SPOOL OFF;
In conclusion, formatting Oracle SQL text-only select output may seem like a daunting task, but by following these simple steps, you can easily make your output more readable and visually appealing. With the use of functions like TO_CHAR, CONCAT, and LPAD, you can customize the output to your liking. So go ahead and give it a try and see the difference it makes in your SQL queries. Happy formatting!
