feat: db schema has now a base

db_schema.sql

@@ -1,4 +1,27 @@
 CREATE TABLE entities (
     cik INT PRIMARY KEY,               -- CIK is now the primary key, ensuring uniqueness
     entityName VARCHAR(255) NOT NULL  -- Name of the company
-);
+);
+
+CREATE TABLE facts (
+    fact VARCHAR(255) PRIMARY KEY, -- Label of the fact
+    label VARCHAR(255),       -- Label of the fact
+    description TEXT, -- Description of the fact
+    unit VARCHAR(255),           -- Unit of the fact
+);
+
+CREATE TABLE data (
+    cik INT,                            -- CIK of the company
+    fact VARCHAR(255),                 
+    end DATE,
+    val INT,
+    accn VARCHAR(255),
+    fy INT,
+    fp VARCHAR(255),
+    form VARCHAR(255),
+    filed DATE,
+    frame VARCHAR(255),
+    PRIMARY KEY (cik, label)
+    FOREIGN KEY (cik) REFERENCES entities(cik),
+    FOREIGN KEY (fact) REFERENCES facts(fact)
+);