What is the purpose of using single quotation marks in PROC FEDSQL?

Using single quotation marks in PROC FEDSQL serves the purpose of specifying a text string, particularly in the WHERE clause. In SQL, including PROC FEDSQL, text strings must be enclosed in quotation marks to distinguish them from other data types, such as variable names or numeric values.

When you specify a condition in a WHERE clause, you often compare a column's value to a text string. For example, if you wanted to filter records where a column called "Country" is equal to "USA", you would write it as WHERE Country = 'USA'. The single quotation marks around 'USA' clearly indicate that this is a string value being used in the comparison.

Other applications of quotation marks are not applicable in this context. Variable names do not require quotation marks and can exist independently. Numeric values are typically not enclosed in quotes, as quotes might indicate a different data type or lead to errors. Formatting output is managed separately through format specifications and does not pertain to the utilization of single quotation marks in PROC FEDSQL.

Thus, using single quotation marks is essential for correctly interpreting and executing string comparisons in PROC FEDSQL, especially within the WHERE clause.