Update README.md

exercises/3-create-a-db-from-csv/README.md

@@ -30,8 +30,14 @@ PRIMARY KEY ('id')
 ```
 To insert a row of data:
 ```py
-c.execute("INSERT INTO users VALUES(?,?,?)", (name, account, balance))
+c.execute("INSERT INTO users(name, account, balance) VALUES(?,?,?)", (name, account, balance))
 ```
+**Note: ** You must specify the columns names otherwise sqlite3 will default to all columns. 
+
+```py
+
+```
+
 Sandbox! dir() and help() the cursor for all the methods possible.
 
 What does executemany do?