Schema builder (columns, types) in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of Laravel's Schema Builder?

Laravel's Schema Builder helps you create and modify database tables using PHP code instead of writing raw SQL. It makes managing database structure easier and more readable.

beginner

How do you add a string column named 'title' to a table using Laravel's Schema Builder?

Use the method $table->string('title'); inside the Schema::create or Schema::table callback to add a string column called 'title'.

beginner

Name three common column types you can define with Laravel's Schema Builder.

Common column types include:

• string for short text
• integer for whole numbers
• boolean for true/false values

intermediate

What method would you use to add a nullable column in Laravel's Schema Builder?

You chain the nullable() method to the column definition, like $table->string('description')->nullable(); to allow the column to hold NULL values.

beginner

How do you create an auto-incrementing primary key column in Laravel's Schema Builder?

Use $table->id(); which creates an unsigned big integer column named 'id' that auto-increments and is the primary key.

Which method adds a date and time column in Laravel's Schema Builder?

A $table->boolean('created_at');

B $table->string('created_at');

C $table->integer('created_at');

D $table->dateTime('created_at');

The dateTime method adds a column that stores date and time values.

How do you make a column optional (can be NULL) in Laravel's Schema Builder?

A Add <code>->optional()</code> after the column type

B Add <code>->nullable()</code> after the column type

C Add <code>->default(NULL)</code> after the column type

D Add <code>->null()</code> after the column type

The nullable() method allows the column to accept NULL values.

What does $table->timestamps(); do in a migration?

A Adds 'created_at' and 'updated_at' timestamp columns

B Adds a single timestamp column named 'timestamps'

C Adds a boolean column named 'timestamps'

D Adds an integer column named 'timestamps'

The timestamps() method adds two columns: created_at and updated_at.

Which column type is best for storing true/false values?

A boolean

B text

C integer

D string

The boolean type stores true or false values efficiently.

How do you drop a column named 'age' using Schema Builder?

A $table->deleteColumn('age');

B $table->remove('age');

C $table->dropColumn('age');

D $table->drop('age');

The correct method to remove a column is dropColumn().

Explain how to add different column types using Laravel's Schema Builder and give examples.

Think about methods like string(), integer(), boolean(), nullable(), and id().

Describe how Laravel's Schema Builder helps manage database tables compared to writing raw SQL.

Focus on benefits of using Schema Builder for beginners and teams.

Practice

1. What does the Schema::create method do in Laravel migrations?

easy

A. Creates a new database table with specified columns

B. Deletes an existing database table

C. Updates data inside a table

D. Runs raw SQL queries directly

Solution

1. Step 1: Understand the purpose of Schema::create

   This method is used to define a new table structure in the database.

2. Step 2: Recognize the role of columns inside the callback

   The callback function receives a Blueprint object to define columns for the new table.

3. Final Answer:

   Creates a new database table with specified columns -> Option A

4. Quick Check:

   Schema::create = create table [OK]

Hint: Schema::create always defines a new table [OK]

Common Mistakes:

• Confusing create with drop or update
• Thinking it modifies data instead of structure
• Assuming it runs raw SQL

2. Which of the following is the correct syntax to add a string column named title in a Laravel migration?

easy

A. $table->varchar('title');

B. $table->string('title');

C. $table->text('title');

D. $table->char('title');

Solution

1. Step 1: Identify the correct method for string columns

   Laravel uses string() to create VARCHAR columns.

2. Step 2: Check the syntax for adding a column

   The syntax is $table->string('column_name'); which matches $table->string('title');.

3. Final Answer:

   $table->string('title'); -> Option B

4. Quick Check:

   String column = $table->string('name') [OK]

Hint: Use $table->string() for VARCHAR columns [OK]

Common Mistakes:

• Using varchar() which does not exist
• Confusing text() with string()
• Using char() without length

3. What will be the resulting column type in the database for this migration code?

$table->integer('age')->unsigned();

medium

A. Unsigned integer column

B. Signed integer column

C. String column named 'age'

D. Boolean column

Solution

1. Step 1: Understand the integer() method

   This creates an integer type column in the database.

2. Step 2: Analyze the effect of unsigned()

   The unsigned() modifier makes the integer only accept positive values (no negatives).

3. Final Answer:

   Unsigned integer column -> Option A

4. Quick Check:

   integer()->unsigned() = unsigned int [OK]

Hint: unsigned() means no negative numbers allowed [OK]

Common Mistakes:

• Ignoring unsigned modifier
• Thinking integer() creates string
• Confusing with boolean type

4. Identify the error in this migration code snippet:

Schema::create('users', function (Blueprint $table) {
    $table->string('email')->nullable;
});

medium

A. String columns cannot be nullable

B. Wrong method name, should be allowNull()

C. Blueprint object is not imported

D. Missing parentheses after nullable method

Solution

1. Step 1: Check the nullable method usage

   In Laravel, nullable is a method and must be called with parentheses ().

2. Step 2: Identify the missing parentheses

   The code uses nullable without (), causing a syntax error.

3. Final Answer:

   Missing parentheses after nullable method -> Option D

4. Quick Check:

   nullable() requires parentheses [OK]

Hint: Always add () after nullable method [OK]

Common Mistakes:

• Writing nullable without ()
• Using allowNull() instead of nullable()
• Assuming string can't be nullable

5. You want to create a table with a primary key id that auto-increments, a nullable description text column, and a price decimal column with 8 digits total and 2 decimal places. Which migration code is correct?

hard

A. Schema::create('products', function (Blueprint $table) { $table->bigIncrements('id'); $table->text('description'); $table->decimal('price', 8, 2); });

B. Schema::create('products', function (Blueprint $table) { $table->integer('id')->autoIncrement(); $table->string('description')->nullable; $table->decimal('price', 8); });

C. Schema::create('products', function (Blueprint $table) { $table->increments('id'); $table->text('description')->nullable(); $table->decimal('price', 8, 2); });

D. Schema::create('products', function (Blueprint $table) { $table->increments('id'); $table->text('description')->nullable; $table->decimal('price', 8, 2); });

Solution

1. Step 1: Check primary key and auto-increment

   $table->increments('id') creates an auto-incrementing primary key integer column.

2. Step 2: Verify nullable text column syntax

   $table->text('description')->nullable(); correctly makes the text column nullable with parentheses.

3. Step 3: Confirm decimal column precision

   $table->decimal('price', 8, 2); defines a decimal with 8 digits total and 2 decimal places.

4. Final Answer:

   Schema::create('products', function (Blueprint $table) { $table->increments('id'); $table->text('description')->nullable(); $table->decimal('price', 8, 2); }); -> Option C

5. Quick Check:

   increments + nullable() + decimal(8,2) = correct [OK]

Hint: Use increments() for PK, nullable() with (), decimal needs precision [OK]

Common Mistakes:

• Forgetting parentheses on nullable()
• Using autoIncrement() instead of increments()
• Missing decimal precision arguments