SQL*Plus is a powerful tool for managing and manipulating data in an Oracle database. However, one of its limitations is its tendency to truncate column names when displaying query results. This can be frustrating for users, especially when working with large datasets that have multiple columns with similar names. In this article, we will discuss how to prevent SQL*Plus truncation of column names without having to individually format each column.
First, let's understand why SQL*Plus truncates column names in the first place. This behavior is due to the default settings of the column formatting feature. By default, SQL*Plus allocates a fixed width for each column and truncates any data that exceeds that width. This is useful for displaying data in a neat and organized manner, but it can be problematic when dealing with longer column names.
To prevent SQL*Plus from truncating column names, we need to modify the column formatting settings. This can be done by using the COLUMN command, which allows us to specify the width and format for each column. However, manually formatting each column can be time-consuming and tedious, especially if we have a large number of columns.
Fortunately, there is a simpler solution – using the SET command to modify the default column formatting settings. The SET COLUMN command allows us to specify the default width and format for all columns in a query. This means that we can prevent SQL*Plus from truncating column names without having to individually format each column.
Let's see how this works in practice. Say we have a table with the following columns: employee_id, first_name, last_name, and department_name. When we query this table in SQL*Plus, the column names will be truncated to employee, first_, last_, and departm respectively.
To prevent this truncation, we can use the following command before running our query:
SET COLUMN employee_id FORMAT A10
SET COLUMN first_name FORMAT A15
SET COLUMN last_name FORMAT A15
SET COLUMN department_name FORMAT A20
This will set the column width for employee_id to 10 characters, first_name and last_name to 15 characters, and department_name to 20 characters. As a result, when we run our query, the column names will no longer be truncated.
But what if we have a table with a large number of columns? Manually setting the column format for each column can be a daunting task. In such cases, we can use the SET COLUMN ALL command, which allows us to specify a default format for all columns in a query.
For example, if we want all columns to have a width of 20 characters, we can use the following command:
SET COLUMN ALL FORMAT A20
This will apply the specified format to all columns in our query, preventing SQL*Plus from truncating column names.
In addition to setting the column width, we can also use the SET COLUMN command to specify other formatting options, such as alignment, headings, and even column titles. This gives us more control over how our query results are displayed in SQL*Plus.
In conclusion, SQL*Plus truncating column names can be a nuisance for users, but it can be easily prevented by modifying the default column formatting settings. By using the SET COLUMN command, we can specify the width and format for all columns, saving us time and effort. So the next time you encounter this issue, remember this handy solution and save yourself from the frustration of truncated column names.
