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Aliased table expressions
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
Only few types of table expressions can leverage code generation to provide the SQL syntax typesafety shown previously, where generated tables are used. All tables, however, allow for dereferencing their fields through Table::field methods:
// "Type-unsafe" aliased table:
Table<?> a = AUTHOR.as("a");
// Get fields from a:
Field<?> id = a.field("ID");
Field<?> firstName = a.field("FIRST_NAME");
The same is true for derived tables, including unnamed derived tables whose synthetic table name is generated by jOOQ:
Table<?> named = table(select(AUTHOR.ID).from(AUTHOR)).as("t");
Table<?> unnamed = table(select(AUTHOR.ID).from(AUTHOR));
Field<?> id = named.field("ID"); // Produces a t.ID reference
Field<?> id = unnamed.field("ID"); // Produces a <generated-alias>.ID reference
Note that if you know that the ID column is of the same type as the AUTHOR.ID column, you can use that again to dereference the column as is explained again in the section dereferencing table columns.
// Now with inferred Integer type Field<Integer> id = named.field(AUTHOR.ID); // Produces a t.ID reference Field<Integer> id = unnamed.field(AUTHOR.ID); // Produces a <generated-alias>.ID reference
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