Added withdraw from user functionality

ddbank.py

@@ -1,6 +1,24 @@
 #!/usr/bin/env python3
 import sqlite3
 import os
+
+def withdraw(a):
+    connDb = sqlite3.connect(a)
+    cur = connDb.cursor()
+    withUser = input("User?: ")
+    userIn = int(input(f'{withUser}: Amount to withdraw: '))
+    cur.execute("SELECT id FROM account where username=?", (withUser, ))
+    userId = cur.fetchone()[0]
+    cur.execute("SELECT balance from balance where id=?", (userId, ))
+    prevAmt = cur.fetchone()[0]
+    if (prevAmt - userIn) < 0:
+        print("*** User cannot have a negative balance. ")
+        withdraw(a)
+    else:
+        cur.execute("UPDATE balance SET balance=(?-?) WHERE id=?", (prevAmt, userIn, userId, ))
+        connDb.commit()
+        connDb.close()
+
 def manBankin(a):
     while True:
         bankNam = a.split(".")[0]
@@ -9,11 +27,11 @@ def manBankin(a):
         2. Deposit
         3. Transfer
         4. User Balance check
-        Q. Quit/Go Back
+        Q. Go Back
         """)
         userIn = input(f"Bank/{bankNam}: ")
         if userIn == "1":
-            print("Withdraw")
+            withdraw(a)
         elif userIn == "2":
             print("Deposit")
         elif userIn == "3":
@@ -53,7 +71,7 @@ def addUser(a):
     userIn = input('What user would you like to add? ')
     cur.execute("INSERT INTO account (username,active) VALUES(?,1)", (userIn,))
     cur.execute("INSERT INTO balance (balance) VALUES(0.00)")
-    cur.execute("INSERT INTO banktrans (username) VALUES(?)", (userIn,))
+    cur.execute("INSERT INTO banktrans (username,amount) VALUES(?,0.00)", (userIn,))
     connDb.commit()
     connDb.close()
 
@@ -64,7 +82,7 @@ def manageBankmenu(a):
         2. Delete a user.
         3. List users.
         4. Banking Menu.
-        Q to quit.
+        Q. Go Back.
         """)
         menuOption = input("Bank: Choose from the menu: ")
         if menuOption == '1':
@@ -101,11 +119,12 @@ def addBank():
          TIMESTAMP  DATETIME DEFAULT CURRENT_TIMESTAMP, ACTIVE BOOLEAN NOT NULL);''')
     connDb.execute('''CREATE TABLE balance
          (ID INTEGER PRIMARY KEY AUTOINCREMENT,
-         BALANCE           REAL    NOT NULL,
+         BALANCE           INTEGER    CHECK(BALANCE >= 0),
          TIMESTAMP  DATETIME DEFAULT CURRENT_TIMESTAMP);''')
     connDb.execute('''CREATE TABLE banktrans
-         (ID INTEGER PRIMARY KEY AUTOINCREMENT,
+         (ID INTEGER PRIMARY KEY,
          USERNAME           TEXT    NOT NULL,
+         AMOUNT             INTEGER NOT NULL,
          TIMESTAMP  DATETIME DEFAULT CURRENT_TIMESTAMP);''')
     connDb.close()
     os.system('clear')