Column Names

A column-name designates a column of a table or view. The name can be unqualified or qualified.

If you specify SQLMODE=ANSI or SQLMODE=FIPS in the SQL Preprocessor options, the unqualified form of a column name is a long identifier, 1 to 18 characters.

If you specify SQLMODE=DATACOM for extended mode in the SQL Preprocessor options, the unqualified form of a column name can be 1 to 32 characters.

The column-name must be alphanumeric and the first character must be alphabetic. The name can contain underscores ( _ ), but not hyphens ( - ).

Do not use a keyword as the name of a column.

The meaning of a column-name depends on its context. A column-name can be used to:

Declare the name of a column, as in the CREATE TABLE statement.
Identify a column, as in the SELECT statement.
Specify values of a column, as in the following contexts:

In functions

A column-name specifies all values of the column in the group or intermediate result table to which the function is applied.

For example, MAX(SALARY) applies the function MAX to all values of the column SALARY in a group.

In GROUP BY or ORDER BY clauses

A column-name specifies all values in the intermediate result table to which the clause is applied.

For example, ORDER BY DEPT orders an intermediate result table by the values of the column DEPT.

In expressions or search conditions

A column-name specifies a value for each row or group to which the expression or search condition is applied.

For example, when the search condition CODE = 20 is applied to a row, the value specified by the column-name CODE is the value of the column CODE in that row.