Working with SQLite in Python

python_sqlite.ipynb

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   "source": [
    "These examples are taken from the [Software Carpentry](https://software-carpentry.org/) lesson for [Databases and SQL](https://swcarpentry.github.io/sql-novice-survey/), specifically the section on [working with databases in Python](https://swcarpentry.github.io/sql-novice-survey/10-prog/index.html).\n",
    "\n",
    "To run these examples, download the [survey.db](https://swcarpentry.github.io/sql-novice-survey/files/survey.db) SQLite database file and place it in the same folder as this notebook."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "78a228e5",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(-49.85, -128.57)\n",
      "(-47.15, -126.72)\n",
      "(-48.87, -123.4)\n"
     ]
    }
   ],
   "source": [
    "import sqlite3\n",
    "\n",
    "connection = sqlite3.connect(\"survey.db\")\n",
    "cursor = connection.cursor()\n",
    "cursor.execute(\"SELECT Site.lat, Site.long FROM Site;\")\n",
    "results = cursor.fetchall()\n",
    "for r in results:\n",
    "    print(r)\n",
    "cursor.close()\n",
    "connection.close()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "96c739ca",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Full name for dyer: William Dyer\n"
     ]
    }
   ],
   "source": [
    "import sqlite3\n",
    "\n",
    "def get_name(database_file, person_id):\n",
    "    query = \"SELECT personal || ' ' || family FROM Person WHERE id='\" + person_id + \"';\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query)\n",
    "    results = cursor.fetchall()\n",
    "    cursor.close()\n",
    "    connection.close()\n",
    "\n",
    "    return results[0][0]\n",
    "\n",
    "print(\"Full name for dyer:\", get_name('survey.db', 'dyer'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "d7f25187",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Full name for dyer: William Dyer\n"
     ]
    }
   ],
   "source": [
    "import sqlite3\n",
    "\n",
    "def get_name(database_file, person_id):\n",
    "    query = \"SELECT personal || ' ' || family FROM Person WHERE id=?;\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, [person_id])\n",
    "    results = cursor.fetchall()\n",
    "    cursor.close()\n",
    "    connection.close()\n",
    "\n",
    "    return results[0][0]\n",
    "\n",
    "print(\"Full name for dyer:\", get_name('survey.db', 'dyer'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "5160cfd4",
   "metadata": {},
   "outputs": [
    {
     "ename": "IndexError",
     "evalue": "list index out of range",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mIndexError\u001b[0m                                Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-4-2481a760cc61>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[1;32m     26\u001b[0m \u001b[0madd_name\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'survey.db'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m(\u001b[0m\u001b[0;34m'barrett'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'Mary'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'Barrett'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     27\u001b[0m \u001b[0;31m# Check it exists\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 28\u001b[0;31m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Full name for barrett:\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mget_name\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'survey.db'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'barrett'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;32m<ipython-input-4-2481a760cc61>\u001b[0m in \u001b[0;36mget_name\u001b[0;34m(database_file, person_id)\u001b[0m\n\u001b[1;32m     21\u001b[0m     \u001b[0mconnection\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mclose\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     22\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 23\u001b[0;31m     \u001b[0;32mreturn\u001b[0m \u001b[0mresults\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m0\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m0\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     24\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     25\u001b[0m \u001b[0;31m# Insert a new name\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
      "\u001b[0;31mIndexError\u001b[0m: list index out of range"
     ]
    }
   ],
   "source": [
    "import sqlite3\n",
    "\n",
    "def add_name(database_file, new_person):\n",
    "    query = \"INSERT INTO Person (id, personal, family) VALUES (?, ?, ?);\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, list(new_person))\n",
    "    cursor.close()\n",
    "    connection.close()\n",
    "\n",
    "\n",
    "def get_name(database_file, person_id):\n",
    "    query = \"SELECT personal || ' ' || family FROM Person WHERE id=?;\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, [person_id])\n",
    "    results = cursor.fetchall()\n",
    "    cursor.close()\n",
    "    connection.close()\n",
    "\n",
    "    return results[0][0]\n",
    "\n",
    "# Insert a new name\n",
    "add_name('survey.db', ('barrett', 'Mary', 'Barrett'))\n",
    "# Check it exists\n",
    "print(\"Full name for barrett:\", get_name('survey.db', 'barrett'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "7ed24475",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Full name for barrett: Mary Barrett\n"
     ]
    }
   ],
   "source": [
    "import sqlite3\n",
    "\n",
    "def add_name(database_file, new_person):\n",
    "    query = \"INSERT INTO Person (id, personal, family) VALUES (?, ?, ?);\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, list(new_person))\n",
    "    cursor.close()\n",
    "    connection.commit()\n",
    "    connection.close()\n",
    "\n",
    "\n",
    "def get_name(database_file, person_id):\n",
    "    query = \"SELECT personal || ' ' || family FROM Person WHERE id=?;\"\n",
    "\n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, [person_id])\n",
    "    results = cursor.fetchall()\n",
    "    cursor.close()\n",
    "    connection.close()\n",
    "\n",
    "    return results[0][0]\n",
    "\n",
    "# Insert a new name\n",
    "add_name('survey.db', ('barrett', 'Mary', 'Barrett'))\n",
    "# Check it exists\n",
    "print(\"Full name for barrett:\", get_name('survey.db', 'barrett'))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "1cf6ed8a",
   "metadata": {},
   "outputs": [],
   "source": [
    "def remove_name(database_file, person_id):\n",
    "    query = 'DELETE from Person where id=?;'\n",
    "    \n",
    "    connection = sqlite3.connect(database_file)\n",
    "    cursor = connection.cursor()\n",
    "    cursor.execute(query, [person_id])\n",
    "    cursor.close()\n",
    "    connection.commit()\n",
    "    connection.close()\n",
    "\n",
    "# remove the name we added to put the database back into its initial state\n",
    "remove_name('survey.db', 'barrett')"
   ]
  }
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