Filter with Where Clauses

This guide shows you how to filter records using where clauses.

Basic Where

active_users = User.where(active: true).all

Multiple Conditions

users = User.where(active: true, role: "admin").all

Chain Where Clauses

users = User
  .where(active: true)
  .where(role: "admin")
  .all

Comparison Operators

Use blocks for comparisons:

# Greater than
adults = User.where { age > 18 }.all

# Less than
young = User.where { age < 30 }.all

# Greater than or equal
User.where { age >= 18 }.all

# Less than or equal
User.where { age <= 65 }.all

# Not equal
User.where { status != "banned" }.all

Range Queries

# Between
User.where { age.between(18, 65) }.all

# In a set
User.where { role.in(["admin", "moderator"]) }.all

Date Comparisons

# Records from last week
User.where { created_at > 1.week.ago }.all

# Records from specific date
User.where { created_at > Time.utc(2024, 1, 1) }.all

# Records between dates
Post.where { published_at.between(start_date, end_date) }.all

NULL Checks

# Where null
User.where(deleted_at: nil).all

# Where not null (use block)
User.where { deleted_at != nil }.all

LIKE Queries

# Contains
User.where { name.like("%john%") }.all

# Starts with
User.where { email.like("admin%") }.all

# Ends with
User.where { email.like("[e-mail]") }.all

OR Conditions

User.where { (role == "admin") | (role == "moderator") }.all

AND Conditions

User.where { (age > 18) & (active == true) }.all

Combine Hash and Block

User.where(active: true).where { age > 18 }.all

Order Results

User.where(active: true)
    .order(created_at: :desc)
    .all

Limit Results

User.where(active: true)
    .limit(10)
    .all

Count Results

count = User.where(active: true).count
puts "Active users: #{count}"

Verify Filtering Works

User.create!(name: "John", email: "[e-mail]", age: 25, active: true)
User.create!(name: "Jane", email: "[e-mail]", age: 30, active: false)

User.where(active: true).count  # => 1
User.where { age > 20 }.count   # => 2

Related

• Find Records

• Build Complex Queries

• Create Query Scopes