QDB recognizes more than 100 SQL keywords related to command names, operators, sorting directives, and table, column, and query constraints. You must use special syntax to use keywords as names of program objects.


The SQL standard specifies a huge number of keywords that you can not use as the names of tables, indexes, columns, databases, user-defined functions, collations, virtual table modules, or any other named object. The list of keywords is so long that few people can remember them all. For most SQL code, your safest bet is to never use any word in the English language as the name of a user-defined object.

If you want to use a keyword as a name, you need to quote it. There are three ways of quoting keywords in QDB:

A keyword in single quotes is interpreted as a literal string if it occurs in a context where a string literal is allowed, otherwise it is understood as an identifier.
A keyword in double-quotes is interpreted as an identifier if it matches a known identifier. Otherwise it is interpreted as a string literal.
A keyword enclosed in square brackets is always understood as an identifier. This is not standard SQL. This quoting mechanism is used by MS Access and SQL Server and is included in QDB for compatibility.

Quoted keywords are unaesthetic. To help you avoid them, QDB allows many keywords to be used unquoted as the names of databases, tables, indices, triggers, views, columns, user-defined functions, collations, attached databases, and virtual function modules. In the list of keywords that follows, keywords that can be used as identifiers are shown in italics. Keywords that must be quoted in order to be used as identifiers are shown in bold.

QDB adds new keywords from time to time when it take on new features. So to prevent your code from being broken by future enhancements, you should normally quote any identifier that is a word in English, even if you do not have to.

The following are the keywords currently recognized by QDB:

Special names

The following words are not keywords in QDB, but are used as names of system objects. They can be used as identifiers for a different type of object.