diff --git a/src/dev/shiza/bulbasaur/alter/Alter.java b/src/dev/shiza/bulbasaur/alter/Alter.java
index f7a9148..3a4e07f 100644
--- a/src/dev/shiza/bulbasaur/alter/Alter.java
+++ b/src/dev/shiza/bulbasaur/alter/Alter.java
@@ -18,5 +18,26 @@ static Alter alter(final @NotNull String table) {
 
   Alter drop(final @NotNull String column);
 
+  Alter modify(final @NotNull String column, final @NotNull String definition);
+
+  Alter modify(final @NotNull String column, final @NotNull ColumnDefinition definition);
+
+  Alter modify(final @NotNull String column, final @NotNull ColumnDefinition... definitions);
+
+  Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull String definition);
+
+  Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull ColumnDefinition definition);
+
+  Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull ColumnDefinition... definitions);
+
   Alter rename(final @NotNull String oldColumn, final @NotNull String newColumn);
 }
diff --git a/src/dev/shiza/bulbasaur/alter/AlterQuery.java b/src/dev/shiza/bulbasaur/alter/AlterQuery.java
index 7365850..8ac1ff3 100644
--- a/src/dev/shiza/bulbasaur/alter/AlterQuery.java
+++ b/src/dev/shiza/bulbasaur/alter/AlterQuery.java
@@ -34,6 +34,53 @@ public Alter add(final @NotNull String column, final @NotNull ColumnDefinition..
         Arrays.stream(definitions).reduce(ColumnDefinitions.empty(), ColumnDefinition::and));
   }
 
+  @Override
+  public Alter modify(final @NotNull String column, final @NotNull String definition) {
+    this.operation = new Modifying(column, definition);
+    return this;
+  }
+
+  @Override
+  public Alter modify(final @NotNull String column, final @NotNull ColumnDefinition definition) {
+    return modify(column, definition.generate());
+  }
+
+  @Override
+  public Alter modify(
+      final @NotNull String column, final @NotNull ColumnDefinition... definitions) {
+    return modify(
+        column,
+        Arrays.stream(definitions).reduce(ColumnDefinitions.empty(), ColumnDefinition::and));
+  }
+
+  @Override
+  public Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull String definition) {
+    this.operation = new Changing(oldColumn, newColumn, definition);
+    return this;
+  }
+
+  @Override
+  public Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull ColumnDefinition definition) {
+    return change(oldColumn, newColumn, definition.generate());
+  }
+
+  @Override
+  public Alter change(
+      final @NotNull String oldColumn,
+      final @NotNull String newColumn,
+      final @NotNull ColumnDefinition... definitions) {
+    return change(
+        oldColumn,
+        newColumn,
+        Arrays.stream(definitions).reduce(ColumnDefinitions.empty(), ColumnDefinition::and));
+  }
+
   @Override
   public Alter drop(final @NotNull String column) {
     this.operation = new Dropping(column);
@@ -75,6 +122,22 @@ public String query() {
     }
   }
 
+  record Modifying(String column, String definition) implements Query {
+
+    @Override
+    public String query() {
+      return "MODIFY " + column + " " + definition;
+    }
+  }
+
+  record Changing(String oldColumn, String newColumn, String definition) implements Query {
+
+    @Override
+    public String query() {
+      return "CHANGE " + oldColumn + " " + newColumn + " " + definition;
+    }
+  }
+
   record Renaming(String oldColumn, String newColumn) implements Query {
 
     @Override
diff --git a/src/dev/shiza/bulbasaur/column/ColumnDefinitions.java b/src/dev/shiza/bulbasaur/column/ColumnDefinitions.java
index a188cb2..06220ed 100644
--- a/src/dev/shiza/bulbasaur/column/ColumnDefinitions.java
+++ b/src/dev/shiza/bulbasaur/column/ColumnDefinitions.java
@@ -27,6 +27,10 @@ public static ColumnDefinition references(
     return () -> "REFERENCES " + referencedTable + " (" + referencedColumn + ")";
   }
 
+  public static ColumnDefinition unique() {
+    return () -> "UNIQUE";
+  }
+
   public static ColumnDefinition defaults(final @NotNull Object defaultValue) {
     return () -> "DEFAULT '" + defaultValue + "'";
   }