SQL and Scikit Learn

SQL

• Aggregate functions

  • AVG, SUM, MIN, MAX, COUNT

  • come after select

  • ↔ < - >

  • ROUND(number_to_round, decimal_places)

  • negative number with round?

  • rounding to nearest thousandth is -3?

• Arithmetic with SQL queries

  • SELECT (4/3)

• Aggregate functions perform their shit vertically in column fields

• Arithmetic functions perform in records rows or horizontally

• Aliasing with Arithmetic

  • SELECT (gross - budget) AS profit

• Aliasing multiple SELECTS

  • SELECT MAX(budget) AS max_budget

  • SELECT MAX(duration) AS max_duration

• Order of execution including ALIAS

  • FROM → WHERE → SELECT (aliases are defined here) → LIMIT

• When dividing two integers, SQL will return an integer

Scikit-Learn

• Supervised Learning

  • Feature

  • Target

  • Data Wrangling

    • EDA

    • Feature Engineering

  • Supervised learning can solve two types of tasks

    • Trying to predict a continuous value (regression problem)

    • Trying to predict a categorical value (A classification problem)

  • Features Matrix (Rows → Samples) + (Columns → Features)

  • Target Vector → What you want to predict in the data (only for Supervised Learning)