How Do I Change Data Type in SAS PROC SQL?

How Do I Change Data Type in SAS PROC SQL?

SAS PROC SQL is a powerful tool for working with data in SAS. One common task is to change the data type of a variable.

In this tutorial, we will learn how to accomplish this using PROC SQL.

The Basics of Changing Data Types

Before we dive into the specifics of changing data types in PROC SQL, let’s first understand the basics. In SAS, data types determine the type of values that can be stored in a variable.

Some common data types include numeric, character, and date/time.

To change the data type of a variable, you need to use the ALTER TABLE statement in PROC SQL. This statement allows you to modify the structure of a table, including changing the data type of one or more columns.

Example: Changing Data Type from Numeric to Character

Let’s say we have a table called “mytable” with a column named “age” that is currently defined as numeric. We want to change its data type to character. Here’s how you can do it:

PROC SQL;
    ALTER TABLE mytable
        MODIFY age CHAR(10);
QUIT;

In this example, we use the MODIFY statement within ALTER TABLE to change the data type of “age” from numeric to character. The CHAR(10) specifies that the column should be 10 characters wide.

Example: Changing Data Type from Character to Numeric

Now let’s consider a scenario where we want to change the data type from character to numeric. Suppose we have a table called “mytable” with a column named “salary” that is currently defined as character. Here’s how you can change its data type to numeric:

PROC SQL;
    ALTER TABLE mytable
        MODIFY salary NUMERIC;
QUIT;

In this example, we use the MODIFY statement within ALTER TABLE to change the data type of “salary” from character to numeric. Since we don’t specify a width or format, SAS will automatically determine the appropriate numeric format based on the data.

Conclusion

Changing data types in SAS PROC SQL is a straightforward process. By using the ALTER TABLE statement with the MODIFY option, you can easily change the data type of a variable from one type to another.

Remember to specify the new data type correctly and consider any formatting requirements for numeric variables.

With this knowledge, you can confidently manipulate your data in PROC SQL and ensure it aligns with your analysis needs.