diff --git a/app/database/migrations/2014_06_27_163032_create_users_table.php b/app/database/migrations/2014_06_27_163032_create_users_table.php
index 7dce4f47b8..ef3ebbabbe 100644
--- a/app/database/migrations/2014_06_27_163032_create_users_table.php
+++ b/app/database/migrations/2014_06_27_163032_create_users_table.php
@@ -36,8 +36,6 @@ class CreateUsersTable extends Migration
                 $table->string('password', 60);
                 $table->string('reset', 32)->nullable();
                 $table->string('remember_token', 255)->nullable();
-                $table->boolean('migrated');
-
                 $table->unique('email');
             }
         );
diff --git a/app/database/migrations/2014_06_27_163145_create_account_types_table.php b/app/database/migrations/2014_06_27_163145_create_account_types_table.php
index 8a05459eaf..3c81582a50 100644
--- a/app/database/migrations/2014_06_27_163145_create_account_types_table.php
+++ b/app/database/migrations/2014_06_27_163145_create_account_types_table.php
@@ -32,7 +32,7 @@ class CreateAccountTypesTable extends Migration
             'account_types', function (Blueprint $table) {
                 $table->increments('id');
                 $table->timestamps();
-                $table->string('type', 50);
+                $table->string('type', 30);
                 $table->boolean('editable');
 
                 $table->unique('type');
diff --git a/app/database/migrations/2014_06_27_163259_create_accounts_table.php b/app/database/migrations/2014_06_27_163259_create_accounts_table.php
index 0af5a60455..8a7251f61f 100644
--- a/app/database/migrations/2014_06_27_163259_create_accounts_table.php
+++ b/app/database/migrations/2014_06_27_163259_create_accounts_table.php
@@ -44,6 +44,7 @@ class CreateAccountsTable extends Migration
                 // connect accounts to account_types
                 $table->foreign('account_type_id')->references('id')->on('account_types')->onDelete('cascade');
 
+                // for a user, the account name must be unique.
                 $table->unique(['user_id', 'account_type_id', 'name']);
             }
         );
diff --git a/app/database/migrations/2014_06_27_163817_create_components_table.php b/app/database/migrations/2014_06_27_163817_create_components_table.php
index 210773199d..605ef98205 100644
--- a/app/database/migrations/2014_06_27_163817_create_components_table.php
+++ b/app/database/migrations/2014_06_27_163817_create_components_table.php
@@ -40,6 +40,7 @@ class CreateComponentsTable extends Migration
                 // connect components to users
                 $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
 
+                // for a user, the component type & name must be unique.
                 $table->unique(['user_id', 'class', 'name']);
             }
         );
diff --git a/app/database/migrations/2014_06_27_163818_create_piggybanks_table.php b/app/database/migrations/2014_06_27_163818_create_piggybanks_table.php
index 25efdcf2ef..0587903fc0 100644
--- a/app/database/migrations/2014_06_27_163818_create_piggybanks_table.php
+++ b/app/database/migrations/2014_06_27_163818_create_piggybanks_table.php
@@ -48,6 +48,8 @@ class CreatePiggybanksTable extends Migration
 
                 // connect account to piggybank.
                 $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
+
+                // for an account, the name must be unique.
                 $table->unique(['account_id', 'name']);
 
             }
diff --git a/app/database/migrations/2014_06_27_164042_create_transaction_currencies_table.php b/app/database/migrations/2014_06_27_164042_create_transaction_currencies_table.php
index be165577cb..8cecacf2e8 100644
--- a/app/database/migrations/2014_06_27_164042_create_transaction_currencies_table.php
+++ b/app/database/migrations/2014_06_27_164042_create_transaction_currencies_table.php
@@ -34,6 +34,9 @@ class CreateTransactionCurrenciesTable extends Migration
                 $table->timestamps();
                 $table->softDeletes();
                 $table->string('code', 3);
+
+                // code must be unique.
+                $table->unique(['code']);
             }
         );
     }
diff --git a/app/database/migrations/2014_06_27_164512_create_transaction_types_table.php b/app/database/migrations/2014_06_27_164512_create_transaction_types_table.php
index 40cf43e973..568704210e 100644
--- a/app/database/migrations/2014_06_27_164512_create_transaction_types_table.php
+++ b/app/database/migrations/2014_06_27_164512_create_transaction_types_table.php
@@ -34,6 +34,9 @@ class CreateTransactionTypesTable extends Migration
                 $table->timestamps();
                 $table->softDeletes();
                 $table->string('type', 50);
+
+                // type must be unique.
+                $table->unique(['type']);
             }
         );
     }
diff --git a/app/database/migrations/2014_06_27_164619_create_recurring_transactions_table.php b/app/database/migrations/2014_06_27_164619_create_recurring_transactions_table.php
index af41979983..e37936f210 100644
--- a/app/database/migrations/2014_06_27_164619_create_recurring_transactions_table.php
+++ b/app/database/migrations/2014_06_27_164619_create_recurring_transactions_table.php
@@ -44,6 +44,10 @@ class CreateRecurringTransactionsTable extends Migration
                 $table->enum('repeat_freq', ['daily', 'weekly', 'monthly', 'quarterly', 'half-year', 'yearly']);
                 $table->smallInteger('skip')->unsigned();
 
+                // connect user id to users
+                $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
+
+                // for a user, the name must be unique
                 $table->unique(['user_id', 'name']);
 
 
diff --git a/app/database/migrations/2014_06_27_164620_create_transaction_journals_table.php b/app/database/migrations/2014_06_27_164620_create_transaction_journals_table.php
index f895bca4d1..7f751797c4 100644
--- a/app/database/migrations/2014_06_27_164620_create_transaction_journals_table.php
+++ b/app/database/migrations/2014_06_27_164620_create_transaction_journals_table.php
@@ -41,6 +41,9 @@ class CreateTransactionJournalsTable extends Migration
                 $table->boolean('completed');
                 $table->date('date');
 
+                // connect users
+                $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
+
                 // connect transaction journals to transaction types
                 $table->foreign('transaction_type_id')->references('id')->on('transaction_types')->onDelete('cascade');
 
@@ -50,8 +53,7 @@ class CreateTransactionJournalsTable extends Migration
                 // connect transaction journals to transaction currencies
                 $table->foreign('transaction_currency_id')->references('id')->on('transaction_currencies')->onDelete('cascade');
 
-                // connect users
-                $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
+
             }
         );
     }
diff --git a/app/database/migrations/2014_06_27_164836_create_transactions_table.php b/app/database/migrations/2014_06_27_164836_create_transactions_table.php
index 917d65e181..38453f93b6 100644
--- a/app/database/migrations/2014_06_27_164836_create_transactions_table.php
+++ b/app/database/migrations/2014_06_27_164836_create_transactions_table.php
@@ -39,14 +39,18 @@ class CreateTransactionsTable extends Migration
                 $table->string('description', 255)->nullable();
                 $table->decimal('amount', 10, 2);
 
-                // connect transactions to transaction journals
-                $table->foreign('transaction_journal_id')->references('id')->on('transaction_journals')->onDelete('cascade');
+                // connect account id:
+                $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
 
                 // connect piggy banks
                 $table->foreign('piggybank_id')->references('id')->on('piggybanks')->onDelete('set null');
 
-                // connect account id:
-                $table->foreign('account_id')->references('id')->on('accounts')->onDelete('cascade');
+                // connect transactions to transaction journals
+                $table->foreign('transaction_journal_id')->references('id')->on('transaction_journals')->onDelete('cascade');
+
+
+
+
 
             }
         );
diff --git a/app/database/migrations/2014_06_27_165344_create_component_transaction_table.php b/app/database/migrations/2014_06_27_165344_create_component_transaction_table.php
index 7cbef507ee..99e1d8649c 100644
--- a/app/database/migrations/2014_06_27_165344_create_component_transaction_table.php
+++ b/app/database/migrations/2014_06_27_165344_create_component_transaction_table.php
@@ -39,6 +39,9 @@ class CreateComponentTransactionTable extends Migration
 
                 // connect to transactions
                 $table->foreign('transaction_id')->references('id')->on('transactions')->onDelete('cascade');
+
+                // combo must be unique:
+                $table->unique(['component_id', 'transaction_id']);
             }
         );
     }
diff --git a/app/database/migrations/2014_07_05_171326_create_component_transaction_journal_table.php b/app/database/migrations/2014_07_05_171326_create_component_transaction_journal_table.php
index b34fbc1aa2..4474c18ec7 100644
--- a/app/database/migrations/2014_07_05_171326_create_component_transaction_journal_table.php
+++ b/app/database/migrations/2014_07_05_171326_create_component_transaction_journal_table.php
@@ -39,6 +39,9 @@ class CreateComponentTransactionJournalTable extends Migration
 
                 // link transaction journals with transaction_journal_id
                 $table->foreign('transaction_journal_id')->references('id')->on('transaction_journals')->onDelete('cascade');
+
+                // combo must be unique:
+                $table->unique(['component_id', 'transaction_journal_id'],'cid_tjid_unique');
             }
         );
     }
diff --git a/app/database/migrations/2014_07_06_123842_create_preferences_table.php b/app/database/migrations/2014_07_06_123842_create_preferences_table.php
index fb74ddd1bc..058c530f2a 100644
--- a/app/database/migrations/2014_07_06_123842_create_preferences_table.php
+++ b/app/database/migrations/2014_07_06_123842_create_preferences_table.php
@@ -38,6 +38,9 @@ class CreatePreferencesTable extends Migration
 
                 // connect preferences to users
                 $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
+
+                // only one preference per name per user
+                $table->unique(['user_id', 'name']);
             }
         );
     }
diff --git a/app/database/migrations/2014_08_06_044416_recurring_transactions_to_components.php b/app/database/migrations/2014_08_06_044416_create_component_recurring_transaction_table.php
similarity index 80%
rename from app/database/migrations/2014_08_06_044416_recurring_transactions_to_components.php
rename to app/database/migrations/2014_08_06_044416_create_component_recurring_transaction_table.php
index 326228af51..e6f25ed2ec 100644
--- a/app/database/migrations/2014_08_06_044416_recurring_transactions_to_components.php
+++ b/app/database/migrations/2014_08_06_044416_create_component_recurring_transaction_table.php
@@ -4,11 +4,11 @@ use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
 /**
- * Class RecurringTransactionsToComponents
+ * Class CreateComponentRecurringTransactionTable
  *
  * @SuppressWarnings(PHPMD.ShortMethodName)
  */
-class RecurringTransactionsToComponents extends Migration
+class CreateComponentRecurringTransactionTable extends Migration
 {
 
     /**
@@ -40,6 +40,10 @@ class RecurringTransactionsToComponents extends Migration
 
                 // link transaction journals with transaction_journal_id
                 $table->foreign('recurring_transaction_id')->references('id')->on('recurring_transactions')->onDelete('cascade');
+
+                // component and recurring transaction must be unique.
+                $table->unique(['component_id','recurring_transaction_id'],'cid_rtid_unique');
+
             }
         );
     }
diff --git a/app/database/migrations/2014_08_12_173919_create_piggy_instance.php b/app/database/migrations/2014_08_12_173919_create_piggybank_repetitions_table.php
similarity index 88%
rename from app/database/migrations/2014_08_12_173919_create_piggy_instance.php
rename to app/database/migrations/2014_08_12_173919_create_piggybank_repetitions_table.php
index 96dbb1ec06..5a8fa36282 100644
--- a/app/database/migrations/2014_08_12_173919_create_piggy_instance.php
+++ b/app/database/migrations/2014_08_12_173919_create_piggybank_repetitions_table.php
@@ -3,7 +3,12 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
-class CreatePiggyInstance extends Migration
+/**
+ * Class CreatePiggyInstance
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
+class CreatePiggybankRepetitionsTable extends Migration
 {
 
     /**
diff --git a/app/database/migrations/2014_08_18_100330_create_piggy_events.php b/app/database/migrations/2014_08_18_100330_create_piggybank_events_table.php
similarity index 68%
rename from app/database/migrations/2014_08_18_100330_create_piggy_events.php
rename to app/database/migrations/2014_08_18_100330_create_piggybank_events_table.php
index 6abd680a19..f598185157 100644
--- a/app/database/migrations/2014_08_18_100330_create_piggy_events.php
+++ b/app/database/migrations/2014_08_18_100330_create_piggybank_events_table.php
@@ -3,7 +3,12 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
-class CreatePiggyEvents extends Migration
+/**
+ * Class CreatePiggybankEventsTable
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
+class CreatePiggybankEventsTable extends Migration
 {
 
     /**
@@ -28,11 +33,16 @@ class CreatePiggyEvents extends Migration
                 $table->increments('id');
                 $table->timestamps();
                 $table->integer('piggybank_id')->unsigned();
+                $table->integer('transaction_journal_id')->unsigned()->nullable();
+
                 $table->date('date');
                 $table->decimal('amount', 10, 2);
 
                 // connect instance to piggybank.
                 $table->foreign('piggybank_id')->references('id')->on('piggybanks')->onDelete('cascade');
+
+                // connect to journal:
+                $table->foreign('transaction_journal_id')->references('id')->on('transaction_journals')->onDelete('set null');
             }
         );
     }
diff --git a/app/database/migrations/2014_08_23_113221_create_reminders_table.php b/app/database/migrations/2014_08_23_113221_create_reminders_table.php
index bf7ac668b4..7a3cbc0997 100644
--- a/app/database/migrations/2014_08_23_113221_create_reminders_table.php
+++ b/app/database/migrations/2014_08_23_113221_create_reminders_table.php
@@ -3,6 +3,11 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
+/**
+ * Class CreateRemindersTable
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
 class CreateRemindersTable extends Migration
 {
 
@@ -31,6 +36,9 @@ class CreateRemindersTable extends Migration
                 $table->date('startdate');
                 $table->date('enddate')->nullable();
                 $table->boolean('active');
+                $table->boolean('notnow')->default(0);
+                $table->integer('remindersable_id')->unsigned()->nullable();
+                $table->string('remindersable_type')->nullable();
 
                 // connect reminders to users
                 $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
diff --git a/app/database/migrations/2014_08_31_153322_create_importmaps_table.php b/app/database/migrations/2014_08_31_153322_create_importmaps_table.php
deleted file mode 100644
index 5d7eeefcf9..0000000000
--- a/app/database/migrations/2014_08_31_153322_create_importmaps_table.php
+++ /dev/null
@@ -1,41 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-use Illuminate\Database\Schema\Blueprint;
-
-class CreateImportmapsTable extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-        Schema::drop('importmaps');
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        Schema::create(
-            'importmaps', function (Blueprint $table) {
-                $table->increments('id');
-                $table->timestamps();
-                $table->integer('user_id')->unsigned();
-                $table->string('file', 500);
-                $table->integer('totaljobs')->unsigned();
-                $table->integer('jobsdone')->unsigned();
-
-                // connect maps to users
-                $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_09_01_052816_create_importentries_table.php b/app/database/migrations/2014_09_01_052816_create_importentries_table.php
deleted file mode 100644
index 5003dfc9d5..0000000000
--- a/app/database/migrations/2014_09_01_052816_create_importentries_table.php
+++ /dev/null
@@ -1,41 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-use Illuminate\Database\Schema\Blueprint;
-
-class CreateImportentriesTable extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-        Schema::drop('importentries');
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        Schema::create(
-            'importentries', function (Blueprint $table) {
-                $table->increments('id');
-                $table->timestamps();
-                $table->string('class', 200);
-                $table->integer('importmap_id')->unsigned();
-                $table->integer('old')->unsigned();
-                $table->integer('new')->unsigned();
-
-                // connect import map.
-                $table->foreign('importmap_id')->references('id')->on('importmaps')->onDelete('cascade');
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_09_02_103101_create_failed_jobs_table.php b/app/database/migrations/2014_09_02_103101_create_failed_jobs_table.php
deleted file mode 100644
index 89cb377e9d..0000000000
--- a/app/database/migrations/2014_09_02_103101_create_failed_jobs_table.php
+++ /dev/null
@@ -1,37 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-use Illuminate\Database\Schema\Blueprint;
-
-class CreateFailedJobsTable extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-        Schema::drop('failed_jobs');
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        Schema::create(
-            'failed_jobs', function (Blueprint $table) {
-                $table->increments('id');
-                $table->text('connection');
-                $table->text('queue');
-                $table->text('payload');
-                $table->timestamp('failed_at');
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_11_10_172053_create_account_meta.php b/app/database/migrations/2014_11_10_172053_create_account_meta_table.php
similarity index 78%
rename from app/database/migrations/2014_11_10_172053_create_account_meta.php
rename to app/database/migrations/2014_11_10_172053_create_account_meta_table.php
index 55281d7748..e465b7a5eb 100644
--- a/app/database/migrations/2014_11_10_172053_create_account_meta.php
+++ b/app/database/migrations/2014_11_10_172053_create_account_meta_table.php
@@ -3,7 +3,12 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
-class CreateAccountMeta extends Migration
+/**
+ * Class CreateAccountMetaTable
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
+class CreateAccountMetaTable extends Migration
 {
 
     /**
@@ -33,6 +38,8 @@ class CreateAccountMeta extends Migration
                 $table->string('name');
                 $table->text('data');
 
+                $table->unique(['account_id', 'name']);
+
 
             }
         );
diff --git a/app/database/migrations/2014_11_15_112449_extend_piggybank_events.php b/app/database/migrations/2014_11_15_112449_extend_piggybank_events.php
deleted file mode 100644
index 8b5880c958..0000000000
--- a/app/database/migrations/2014_11_15_112449_extend_piggybank_events.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-use Illuminate\Database\Schema\Blueprint;
-
-class ExtendPiggybankEvents extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        Schema::table(
-            'piggybank_events', function (Blueprint $table) {
-                $table->integer('transaction_journal_id')->unsigned()->nullable();
-                $table->foreign('transaction_journal_id')->references('id')->on('transaction_journals')->onDelete('set null');
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_11_17_194734_event_table_additions_1.php b/app/database/migrations/2014_11_17_194734_event_table_additions_1.php
deleted file mode 100644
index 6ccfb73235..0000000000
--- a/app/database/migrations/2014_11_17_194734_event_table_additions_1.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-use Illuminate\Database\Schema\Blueprint;
-
-class EventTableAdditions1 extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-        //
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        // remove some fields:
-        Schema::table(
-            'reminders', function (Blueprint $table) {
-                $table->boolean('notnow')->default(0);
-                $table->integer('remindersable_id')->unsigned()->nullable();
-                $table->string('remindersable_type')->nullable();
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_11_25_204833_cacheTable.php b/app/database/migrations/2014_11_25_204833_cacheTable.php
deleted file mode 100644
index 2ffbce905d..0000000000
--- a/app/database/migrations/2014_11_25_204833_cacheTable.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-use Illuminate\Database\Migrations\Migration;
-
-class CacheTable extends Migration
-{
-
-    /**
-     * Reverse the migrations.
-     *
-     * @return void
-     */
-    public function down()
-    {
-        Schema::drop('cache');
-    }
-
-    /**
-     * Run the migrations.
-     *
-     * @return void
-     */
-    public function up()
-    {
-        Schema::create(
-            'cache', function ($table) {
-                $table->string('key')->unique();
-                $table->text('value');
-                $table->integer('expiration');
-            }
-        );
-    }
-
-}
diff --git a/app/database/migrations/2014_11_29_135749_transactiongroups.php b/app/database/migrations/2014_11_29_135749_create_transaction_groups_table.php
similarity index 85%
rename from app/database/migrations/2014_11_29_135749_transactiongroups.php
rename to app/database/migrations/2014_11_29_135749_create_transaction_groups_table.php
index 09fecd7feb..31dca7cda5 100644
--- a/app/database/migrations/2014_11_29_135749_transactiongroups.php
+++ b/app/database/migrations/2014_11_29_135749_create_transaction_groups_table.php
@@ -3,7 +3,12 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
-class Transactiongroups extends Migration
+/**
+ * Class CreateTransactionGroupsTable
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
+class CreateTransactionGroupsTable extends Migration
 {
 
     /**
diff --git a/app/database/migrations/2014_11_29_140217_transactiongroupsjoin.php b/app/database/migrations/2014_11_29_140217_create_transaction_group_transaction_journal_table.php
similarity index 81%
rename from app/database/migrations/2014_11_29_140217_transactiongroupsjoin.php
rename to app/database/migrations/2014_11_29_140217_create_transaction_group_transaction_journal_table.php
index ca3c9c1c6d..7a275b68d6 100644
--- a/app/database/migrations/2014_11_29_140217_transactiongroupsjoin.php
+++ b/app/database/migrations/2014_11_29_140217_create_transaction_group_transaction_journal_table.php
@@ -3,7 +3,12 @@
 use Illuminate\Database\Migrations\Migration;
 use Illuminate\Database\Schema\Blueprint;
 
-class Transactiongroupsjoin extends Migration
+/**
+ * Class CreateTransactionGroupTransactionJournalTable
+ *
+ * @SuppressWarnings(PHPMD.ShortMethodName)
+ */
+class CreateTransactionGroupTransactionJournalTable extends Migration
 {
 
     /**
@@ -31,9 +36,11 @@ class Transactiongroupsjoin extends Migration
                 $table->integer('transaction_group_id')->unsigned();
                 $table->integer('transaction_journal_id')->unsigned();
 
+                // link to foreign tables.
                 $table->foreign('transaction_group_id', 'tr_grp_id')->references('id')->on('transaction_groups')->onDelete('cascade');
                 $table->foreign('transaction_journal_id', 'tr_trj_id')->references('id')->on('transaction_journals')->onDelete('cascade');
 
+                // add unique.
                 $table->unique(['transaction_group_id', 'transaction_journal_id'], 'tt_joined');
             }
         );