[db] fixed database code

db/pyheatpump.sql

@@ -10,7 +10,7 @@ CREATE TABLE IF NOT EXISTS variable (
 	type CHAR(1) NOT NULL,
 	address INT NOT NULL,
 	unit VARCHAR(5) NULL,
-	last_update DATETIME NULL,
+	last_update DATE NULL,
 
 
 	FOREIGN KEY (type) REFERENCES var_type(slabel)
@@ -21,7 +21,7 @@ CREATE TABLE IF NOT EXISTS variable (
 CREATE TABLE IF NOT EXISTS var_value (
 	type CHAR(1) NOT NULL,
 	address INT NOT NULL,
-	time DATETIME DEFAULT CURRENT_TIMESTAMP,
+	time DATE DEFAULT CURRENT_TIMESTAMP,
 	value INT NOT NULL,
 
 	FOREIGN KEY (type) REFERENCES variable(type)