Make db creation better

sql/card_set.sql

@@ -0,0 +1,9 @@
+create table card_set
+(
+    id       INTEGER
+        primary key autoincrement,
+    name     TEXT not null,
+    forward  TEXT not null,
+    backward TEXT not null,
+    filter   TEXT not null
+);

sql/card_stats.sql

@@ -0,0 +1,13 @@
+create table card_stats
+(
+    id          INTEGER
+        primary key autoincrement,
+    word_id     INTEGER           not null
+        references words
+            on delete cascade,
+    set_id      TEXT              not null
+        references card_set
+            on delete cascade,
+    score       INTEGER default 1 not null,
+    last_opened integer           not null
+);

sql/settings.sql

@@ -0,0 +1,5 @@
+create table settings
+(
+    id    text primary key,
+    value text
+);

sql/word_group.sql

@@ -0,0 +1,6 @@
+create table word_group
+(
+    id   INTEGER
+        primary key autoincrement,
+    name TEXT not null
+);

sql/words.sql

@@ -0,0 +1,13 @@
+create table words
+(
+    id       INTEGER
+        primary key autoincrement,
+    key      TEXT              not null,
+    value    TEXT              not null,
+    tags     TEXT              not null,
+    more     TEXT,
+    group_id integer default 1 not null
+        constraint words_word_group_id_fk
+            references word_group
+            on update cascade on delete cascade
+);