Intersystems Caché SQL. Different behaviour trailing withespaces vs leading withespaces

Question

Given:

• A table tA with an "ID" and a "Description" columns
• "Description" is a string column.

• The contents of the table are:

  ID || Description
  1 || "String1"
  2 || "String2"
  3 || "String3"

If I execute the following SQL query:
"SELECT ID FROM tA WHERE Description = 'String2'" it returns 2 (as expected)

But:

If I execute the following SQL query:
"SELECT ID FROM tA WHERE Description = 'String2 '" (trailing withespaces) it also returns 2! (as it is an exact comparison, it should return NONE)

If I execute the following SQL query:
"SELECT ID FROM tA WHERE Description = ' String2'" (leading withespaces) it returns NONE (as expected)

Do you know what is the reason of this difference in behaviour?

Thanks in advance.

Answer 1

You need to use "%EXACT" around your column name. This should return no records: "SELECT ID FROM tA WHERE %EXACT(Description) = 'String2 '"