优化表结构，增加表数据

sql/initial.sql

@@ -1,11 +1,13 @@
 CREATE TABLE stock
 (
-    code        varchar primary key,
+    code        varchar not null,
+    name        varchar not null,
     fullname    varchar,
     industry    varchar,
     listed_date date,
     market      varchar,
-    name        varchar
+    exchange    varchar,
+    primary key (code)
 );
 
 
@@ -13,22 +15,22 @@ CREATE TABLE daily
 (
     code                varchar not null,
     trade_date          date    not null,
-    open                double  not null,
-    close               double  not null,
-    high                double  not null,
-    low                 double  not null,
-    previous_close      double  not null,
-    turnover            double  not null,
-    volume              integer not null,
-    price_change_amount double  not null,
-    factor              double  not null,
+    open                double,
+    close               double,
+    high                double,
+    low                 double,
+    previous_close      double,
+    turnover            double,
+    volume              integer,
+    price_change_amount double,
+    factor              double,
     primary key (code, trade_date)
 );
 
 CREATE TABLE finance_indicator
 (
-    code                                             varchar,
-    year                                             integer,
+    code                                             varchar not null,
+    year                                             integer not null,
     accounts_payable                                 double,
     accounts_payable_to_total_assets_ratio           double,
     accounts_receivable                              double,