Basic Language Elements › Column Names › Column-Name Qualifiers to Avoid Ambiguity › Table Designators

Table Designators

A qualifier that designates a specific object table is a table designator. The clause that identifies the object tables also establishes the table designators for these tables.

For example, the object tables of an expression in a SELECT clause are named in the FROM clause that follows the SELECT, as in this partial statement:

 SELECT Z.CODE, MYTABLE.CODE

 FROM X.MYTABLE Z, MYTABLE,

 WHERE . . .

A name that follows a table or view name is a correlation-name and a table designator. In the previous example, Z is a table designator and qualifies the first column name after SELECT.

A table-name, view-name or synonym that is not followed by a correlation-name is a table designator. In the previous example, MYTABLE is a designator and qualifies the second column-name after SELECT.