Modified SqLite platform to generate at least non failing migration scripts.

Note: If you want to alter a table in SqLite, the best option is to recreate the table with the new layout

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/SQLiteDdl.java

@@ -5,7 +5,10 @@ import io.ebeaninternal.dbmigration.ddlgeneration.DdlBuffer;
 import io.ebeaninternal.dbmigration.ddlgeneration.DdlOptions;
 
 /**
- * DB2 platform specific DDL.
+ * SQLite platform specific DDL.
+ * 
+ * Note: SQLite has very limited alter capabilities. Altering a column is not
+ * supported and may need a recreation of the whole table
  */
 public class SQLiteDdl extends PlatformDdl {
 
@@ -27,7 +30,47 @@ public class SQLiteDdl extends PlatformDdl {
 
   @Override
   public String alterTableAddForeignKey(DdlOptions options, WriteForeignKey request) {
-    // not supported
-    return null;
+    return "-- not supported: " + super.alterTableAddForeignKey(options, request);
   }
+
+  @Override
+  public String alterTableDropForeignKey(String tableName, String fkName) {
+    return "-- not supported: " + super.alterTableDropForeignKey(tableName, fkName);
+  }
+
+  @Override
+  public String alterTableAddCheckConstraint(String tableName, String checkConstraintName, String checkConstraint) {
+    return "-- not supported: " + super.alterTableAddCheckConstraint(tableName, checkConstraintName, checkConstraint);
+  }
+
+  @Override
+  public String alterTableDropConstraint(String tableName, String constraintName) {
+    return "-- not supported: " + super.alterTableDropConstraint(tableName, constraintName);
+  }
+
+  @Override
+  public String alterTableAddUniqueConstraint(String tableName, String uqName, String[] columns, String[] nullableColumns) {
+    return "-- not supported: " + super.alterTableAddUniqueConstraint(tableName, uqName, columns, nullableColumns);
+  }
+
+  @Override
+  public String alterTableDropUniqueConstraint(String tableName, String uniqueConstraintName) {
+    return "-- not supported: " + super.alterTableDropUniqueConstraint(tableName, uniqueConstraintName);
+  }
+
+  @Override
+  public String alterColumnDefaultValue(String tableName, String columnName, String defaultValue) {
+    return "-- not supported: " + super.alterColumnDefaultValue(tableName, columnName, defaultValue);
+  }
+
+  @Override
+  public String alterColumnType(String tableName, String columnName, String type) {
+    return "-- not supported: " + super.alterColumnType(tableName, columnName, type);
+  }
+
+  @Override
+  public String alterColumnNotnull(String tableName, String columnName, boolean notnull) {
+    return "-- not supported: " + super.alterColumnNotnull(tableName, columnName, notnull);
+  }
+
 }