You can find the SELECT statement for this recipe in the companion code file.

To create a logical table that returns the current date as a constant, do the following:

We created a very simple table with one row and one column. This table will always return the current date at midnight; it is useful to filter records based on moving dates, or simply to display it in a report header. Moreover, since the table has only one row, we can join it anywhere without creating dangerous Cartesian products. Even with a CROSS JOIN, it will always multiply the results by one.

In SQL Server constants are generated with a SELECT statement without the FROM clause. If you want to display Eat at Joe's, it's as simple as:

select "Eat at Joe's"

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In other RDBMS, you may find a different syntax: in Oracle, for example, the current date at midnight can be obtained with the sentence:

SELECT TRUNC(SYSDATE) DateValue FROM DUAL;

And the logical table would work just the same.