diff --git a/table/annotation-processor/build.gradle b/table/annotation-processor/build.gradle
index 38901440..54483d56 100644
--- a/table/annotation-processor/build.gradle
+++ b/table/annotation-processor/build.gradle
@@ -7,4 +7,5 @@ dependencies {
   api project(':table:core')
 
   implementation "org.apache.commons:commons-text:1.8"
+  implementation "org.apache.commons:commons-collections4:4.1"
 }
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/AnnotationElement.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/AnnotationElement.java
new file mode 100644
index 00000000..9281b0e9
--- /dev/null
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/AnnotationElement.java
@@ -0,0 +1,34 @@
+package com.riiablo.table.annotation;
+
+import java.lang.annotation.Annotation;
+import java.util.Map;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
+import javax.lang.model.element.ExecutableElement;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+
+abstract class AnnotationElement<A extends Annotation> {
+  protected final Context context;
+  protected final A annotation;
+  protected final AnnotationMirror mirror;
+
+  protected AnnotationElement(Context context, A annotation, AnnotationMirror mirror) {
+    this.context = context;
+    this.annotation = annotation;
+    this.mirror = mirror;
+  }
+
+  Map<? extends ExecutableElement, ? extends AnnotationValue>
+  defaults() {
+    return context.elementUtils.getElementValuesWithDefaults(mirror);
+  }
+
+  @Override
+  public String toString() {
+    return new ToStringBuilder(this)
+        .append("context", context)
+        .append("annotation", annotation)
+        .append("mirror", mirror)
+        .toString();
+  }
+}
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Constants.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Constants.java
index 91037748..244aca9c 100644
--- a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Constants.java
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Constants.java
@@ -10,6 +10,7 @@ final class Constants {
 
   static final ClassName STRING = ClassName.get(String.class);
   static final ClassName PRIMARY_KEY = ClassName.get(PrimaryKey.class);
+  static final ClassName FORMAT = ClassName.get(Format.class);
 
   static final TypeName[] PRIMARY_KEY_TYPES = { TypeName.INT, STRING };
 
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Context.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Context.java
index df103e63..fef1ba78 100644
--- a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Context.java
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/Context.java
@@ -67,7 +67,7 @@ class Context {
       }
     }
 
-    messager.printMessage(kind, builder);
+    messager.printMessage(kind, builder, element, annotationMirror, annotationValue);
   }
 
   void error(String message, Object... args) {
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FieldElement.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FieldElement.java
new file mode 100644
index 00000000..3be893a1
--- /dev/null
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FieldElement.java
@@ -0,0 +1,38 @@
+package com.riiablo.table.annotation;
+
+import java.util.Collection;
+import javax.lang.model.element.VariableElement;
+
+final class FieldElement {
+  static FieldElement get(Context context, VariableElement element) {
+    FormatElement formatElement = FormatElement.get(context, element);
+    PrimaryKeyElement primaryKeyElement = PrimaryKeyElement.get(context, element);
+
+    return new FieldElement(element, formatElement, primaryKeyElement);
+  }
+
+  static FieldElement firstPrimaryKey(Collection<FieldElement> fields) {
+    for (FieldElement field : fields) {
+      if (field.primaryKeyElement != null || Constants.isPrimaryKey(field.element)) {
+        return field;
+      }
+    }
+
+    return null;
+  }
+
+  final VariableElement element;
+  final FormatElement formatElement;
+  final PrimaryKeyElement primaryKeyElement;
+
+  FieldElement(VariableElement element, FormatElement formatElement, PrimaryKeyElement primaryKeyElement) {
+    this.element = element;
+    this.formatElement = formatElement;
+    this.primaryKeyElement = primaryKeyElement;
+  }
+
+  @Override
+  public String toString() {
+    return element.toString();
+  }
+}
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FormatElement.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FormatElement.java
new file mode 100644
index 00000000..2b01abf0
--- /dev/null
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/FormatElement.java
@@ -0,0 +1,17 @@
+package com.riiablo.table.annotation;
+
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.VariableElement;
+
+final class FormatElement extends AnnotationElement<Format> {
+  static FormatElement get(Context context, VariableElement element) {
+    Format annotation = element.getAnnotation(Format.class);
+    if (annotation == null) return null;
+    AnnotationMirror mirror = context.getAnnotationMirror(element, Constants.FORMAT);
+    return new FormatElement(context, annotation, mirror);
+  }
+
+  FormatElement(Context context, Format annotation, AnnotationMirror mirror) {
+    super(context, annotation, mirror);
+  }
+}
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/PrimaryKeyElement.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/PrimaryKeyElement.java
index 0e34cc4b..4f2f8383 100644
--- a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/PrimaryKeyElement.java
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/PrimaryKeyElement.java
@@ -1,63 +1,17 @@
 package com.riiablo.table.annotation;
 
-import java.util.Collection;
 import javax.lang.model.element.AnnotationMirror;
-import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.VariableElement;
-import org.apache.commons.lang3.builder.ToStringBuilder;
 
-final class PrimaryKeyElement {
-  static PrimaryKeyElement find(
-      Context context,
-      TypeElement element,
-      Collection<VariableElement> elements
-  ) {
-    VariableElement firstAcceptableElement = null, primaryKeyElement = null;
-    for (VariableElement e : elements) {
-      if (firstAcceptableElement == null && Constants.isPrimaryKey(e)) {
-        firstAcceptableElement = e;
-      }
-
-      PrimaryKey annotation = e.getAnnotation(PrimaryKey.class);
-      if (annotation != null) {
-        if (primaryKeyElement == null) {
-          primaryKeyElement = e;
-        } else {
-          context.error(
-              e, context.getAnnotationMirror(e, Constants.PRIMARY_KEY),
-              "{} already declared as {}", primaryKeyElement, PrimaryKey.class);
-        }
-      }
-    }
-
-    if (primaryKeyElement == null) {
-      if (firstAcceptableElement == null) {
-        context.error(element, "{element} did not declare any {}", PrimaryKey.class);
-        return null;
-      }
-
-      context.warn(element, "{element} did not declare any {}, using {}",
-          PrimaryKey.class, firstAcceptableElement);
-      primaryKeyElement = firstAcceptableElement;
-    }
-
-    AnnotationMirror primaryKeyMirror = context.getAnnotationMirror(primaryKeyElement, Constants.PRIMARY_KEY);
-    return new PrimaryKeyElement(primaryKeyElement, primaryKeyMirror);
+final class PrimaryKeyElement extends AnnotationElement<PrimaryKey> {
+  static PrimaryKeyElement get(Context context, VariableElement element) {
+    PrimaryKey annotation = element.getAnnotation(PrimaryKey.class);
+    if (annotation == null) return null;
+    AnnotationMirror mirror = context.getAnnotationMirror(element, Constants.PRIMARY_KEY);
+    return new PrimaryKeyElement(context, annotation, mirror);
   }
 
-  final VariableElement element;
-  final AnnotationMirror mirror;
-
-  PrimaryKeyElement(VariableElement element, AnnotationMirror mirror) {
-    this.element = element;
-    this.mirror = mirror;
-  }
-
-  @Override
-  public String toString() {
-    return new ToStringBuilder(this)
-        .append("element", element)
-        .append("mirror", mirror)
-        .toString();
+  PrimaryKeyElement(Context context, PrimaryKey annotation, AnnotationMirror mirror) {
+    super(context, annotation, mirror);
   }
 }
diff --git a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/SchemaElement.java b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/SchemaElement.java
index 1c56c063..f0d19252 100644
--- a/table/annotation-processor/src/main/java/com/riiablo/table/annotation/SchemaElement.java
+++ b/table/annotation-processor/src/main/java/com/riiablo/table/annotation/SchemaElement.java
@@ -2,37 +2,63 @@ package com.riiablo.table.annotation;
 
 import com.squareup.javapoet.ClassName;
 import java.util.ArrayList;
-import java.util.List;
+import java.util.Collection;
+import java.util.Iterator;
 import javax.lang.model.element.Element;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.TypeMirror;
+import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.collections4.IteratorUtils;
+import org.apache.commons.collections4.Predicate;
 import org.apache.commons.lang3.builder.ToStringBuilder;
 
 final class SchemaElement {
-  static SchemaElement get(Context context, Element element) {
+  static SchemaElement get(final Context context, Element element) {
     TypeElement typeElement = (TypeElement) element;
-    List<VariableElement> columns = collectColumns(context, typeElement);
-    PrimaryKeyElement primaryKeyElement = PrimaryKeyElement.find(context, typeElement, columns);
+    Collection<FieldElement> fields = collectFieldElements(context, typeElement);
 
-    // for (VariableElement e : columns) {
-    //   System.out.println(e);
-    // }
+    final FieldElement primaryKeyFieldElement;
+    Collection<FieldElement> primaryKeys = CollectionUtils.select(fields, new Predicate<FieldElement>() {
+      @Override
+      public boolean evaluate(FieldElement e) {
+        return e.primaryKeyElement != null;
+      }
+    });
+    if (primaryKeys.size() >= 1) {
+      Iterator<FieldElement> it = primaryKeys.iterator();
+      primaryKeyFieldElement = it.next();
+      for (FieldElement e : IteratorUtils.asIterable(it)) {
+        context.warn(e.element, e.primaryKeyElement.mirror,
+            "{} already declared as {}",
+            primaryKeyFieldElement, PrimaryKey.class);
+      }
+    } else {
+      primaryKeyFieldElement = FieldElement.firstPrimaryKey(fields);
+      if (primaryKeyFieldElement == null) {
+        context.error(element, "{element} did not declare any {}", PrimaryKey.class);
+        return null;
+      }
+
+      context.warn(element,
+          "{element} did not declare any {}, using {}",
+          PrimaryKey.class, primaryKeyFieldElement);
+    }
 
     TableElement tableElement = TableElement.get(context, typeElement);
     SerializerElement serializerElement = SerializerElement.get(context, typeElement);
 
-    return new SchemaElement(typeElement, tableElement, serializerElement);
+    return new SchemaElement(typeElement, tableElement, serializerElement, primaryKeyFieldElement);
   }
 
-  static List<VariableElement> collectColumns(Context context, TypeElement typeElement) {
-    List<VariableElement> columns = new ArrayList<>();
+  static Collection<FieldElement> collectFieldElements(Context context, TypeElement typeElement) {
+    Collection<FieldElement> columns = new ArrayList<>();
     TypeElement superclassElement = typeElement;
     for (;;) {
       for (Element e : superclassElement.getEnclosedElements()) {
         switch (e.getKind()) {
           case FIELD:
-            columns.add((VariableElement) e);
+            columns.add(FieldElement.get(context, (VariableElement) e));
             break;
         }
       }
@@ -50,14 +76,17 @@ final class SchemaElement {
   final TypeElement element;
   final TableElement tableElement;
   final SerializerElement serializerElement;
+  final FieldElement primaryKeyFieldElement;
 
   SchemaElement(
       TypeElement element,
       TableElement tableElement,
-      SerializerElement serializerElement) {
+      SerializerElement serializerElement,
+      FieldElement primaryKeyFieldElement) {
     this.element = element;
     this.tableElement = tableElement;
     this.serializerElement = serializerElement;
+    this.primaryKeyFieldElement = primaryKeyFieldElement;
   }
 
   @Override
@@ -66,6 +95,7 @@ final class SchemaElement {
         .append("element", element)
         .append("tableElement", tableElement)
         .append("serializerElement", serializerElement)
+        .append("primaryKeyFieldElement", primaryKeyFieldElement)
         .toString();
   }
 }