Add words

20230211045705_words.down.sql

@@ -0,0 +1,5 @@
+BEGIN;
+DROP TABLE word_form_example_texts;
+DROP TABLE word_forms;
+DROP TABLE words;
+COMMIT;

20230211045705_words.up.sql

@@ -0,0 +1,25 @@
+BEGIN;
+
+CREATE TABLE words (
+    id BIGSERIAL PRIMARY KEY,
+    language_id BIGINT NOT NULL REFERENCES languages (id),
+    primary_form VARCHAR NOT NULL,
+    CONSTRAINT primary_form_is_sane_text CHECK (is_sane_text(primary_form))
+);
+
+CREATE TABLE word_forms (
+    id BIGSERIAL PRIMARY KEY,
+    word_id BIGINT NOT NULL REFERENCES words (id),
+    value VARCHAR NOT NULL,
+    CONSTRAINT value_is_sane_text CHECK (is_sane_text(value))
+);
+
+CREATE TABLE word_form_example_texts (
+    id BIGSERIAL PRIMARY KEY,
+    word_form_id BIGINT NOT NULL REFERENCES word_forms (id),
+    example_text_id BIGINT NOT NULL REFERENCES example_texts (id)
+);
+
+CREATE UNIQUE INDEX word_forms_word_value_index ON word_forms (word_id, value);
+
+COMMIT;