[#7148] Improved implicit join code generation

If table A references table B only once, then B is a much better method name than the foreign key name itself.

jOOQ-codegen/src/main/java/org/jooq/util/DefaultGeneratorStrategy.java

@@ -159,6 +159,16 @@ public class DefaultGeneratorStrategy extends AbstractGeneratorStrategy {
 
     @Override
     public String getJavaMethodName(Definition definition, Mode mode) {
+        // [#7148] If table A references table B only once, then B is the ideal name
+        //         for the implicit JOIN path. Otherwise, fall back to the foreign key name
+        if (definition instanceof ForeignKeyDefinition) {
+            ForeignKeyDefinition fk = (ForeignKeyDefinition) definition;
+            TableDefinition referenced = fk.getReferencedTable();
+
+            if (fk.getKeyTable().getForeignKeys(referenced).size() == 1)
+                return getJavaMethodName(referenced, mode);
+        }
+
         return getJavaClassName0LC(definition, Mode.DEFAULT);
     }
 

jOOQ-meta/src/main/java/org/jooq/util/AbstractTableDefinition.java

@@ -97,6 +97,17 @@ implements TableDefinition {
         return getDatabase().getRelations().getForeignKeys(this);
     }
 
+    @Override
+    public final List<ForeignKeyDefinition> getForeignKeys(TableDefinition referenced) {
+        List<ForeignKeyDefinition> result = new ArrayList<ForeignKeyDefinition>();
+
+        for (ForeignKeyDefinition key : getForeignKeys())
+            if (referenced.equals(key.getReferencedTable()))
+                result.add(key);
+
+        return result;
+    }
+
     @Override
     public final List<CheckConstraintDefinition> getCheckConstraints() {
         return getDatabase().getRelations().getCheckConstraints(this);

jOOQ-meta/src/main/java/org/jooq/util/TableDefinition.java

@@ -90,6 +90,11 @@ public interface TableDefinition extends Definition {
      */
     List<ForeignKeyDefinition> getForeignKeys();
 
+    /**
+     * Get the foreign keys for this table referencing a specific table.
+     */
+    List<ForeignKeyDefinition> getForeignKeys(TableDefinition referenced);
+
     /**
      * Get the <code>CHECK</code> constraints for this table.
      */