Laravel Generate Based On Foreign Key
- Running Migrations
- Tables
- Columns
- Indexes
- What Is Php Laravel
- Laravel Generate Based On Foreign Key Definition
- Laravel Generate Based On Foreign Key Youtube
Jan 27, 2015 This tutorial shows how you can use foreign keys using relationships in laravel 4. In this I have used a popular example of users and their profile information being in two separate tables with foreign key referencing a primary key in another. Jun 22, 2015 Notice we're including an integer-based column named todolistid in the tasks table, followed by a specification that this column be defined as a foreign key. In doing so, Laravel will ensure that the column is indexed, and additionally you'll optionally be able to determine what happens to these records should the parent be updated or deleted. Mar 20, 2019 There is one change in Laravel 5.8 that is not mentioned in the official Upgrade Guide but caused me problems - I couldn't create a foreign key migration, and spent half-hour until found out the reasons. So I want to share, maybe you will encounter the same thing. Jan 23, 2019 Creating Foreign Keys via Laravel Migration. The userid column in userprofiles is a Foreign Key to id in users. I was trying to do this. I'm creating a survey and in order to create a question I need to get the surveyid from the survey table and place in it a create a question view in a hidden field in a form and pass it to the question controller.
Sep 22, 2018 Laravel really excels at facilitating deft management and navigation of table relations, but you'll need to understand how to properly configure these relationships before taking advantage of them. Consider the TODOParrot example application's rel. Oct 27, 2018 Creating Foreign Key in Laravel Migrations. I tried to create two tables with the second table having a foreign key that reference the first table.
Introduction
Migrations are like version control for your database, allowing your team to easily modify and share the application's database schema. Migrations are typically paired with Laravel's schema builder to easily build your application's database schema. If you have ever had to tell a teammate to manually add a column to their local database schema, you've faced the problem that database migrations solve.
The Laravel Schemafacade provides database agnostic support for creating and manipulating tables across all of Laravel's supported database systems.
Generating Migrations
To create a migration, use the make:migrationArtisan command:
The new migration will be placed in your database/migrations directory. Each migration file name contains a timestamp which allows Laravel to determine the order of the migrations.
The --table and --create options may also be used to indicate the name of the table and whether the migration will be creating a new table. These options simply pre-fill the generated migration stub file with the specified table:
If you would like to specify a custom output path for the generated migration, you may use the --path option when executing the make:migration command. The given path should be relative to your application's base path.
Migration Structure
A migration class contains two methods: up and down. The up method is used to add new tables, columns, or indexes to your database, while the down method should simply reverse the operations performed by the up method.
Within both of these methods you may use the Laravel schema builder to expressively create and modify tables. To learn about all of the methods available on the Schema builder, check out its documentation. For example, this migration example creates a flights table:
Running Migrations
To run all of your outstanding migrations, execute the migrate Artisan command:
{note} If you are using the Homestead virtual machine, you should run this command from within your virtual machine.
Forcing Migrations To Run In Production
Some migration operations are destructive, which means they may cause you to lose data. In order to protect you from running these commands against your production database, you will be prompted for confirmation before the commands are executed. To force the commands to run without a prompt, use the --force flag:
So when Elon Musk says he’s going to launch the most powerful rocket in the world from the very same launch pad that sent the Apollo 11 astronauts to the moon, he’s going to get a little attention.That’s exactly the big event Musk is touting Tuesday. That’s what happens when you’re the founder of a rocket company, a co-founder of an electric car and solar panel company, a co-founder of PayPal and, not for nothing, have an actual movie superhero—Iron Man—based partly on you. Spacex's next-generation rocket engine blew up during a key tes. No one makes news like makes news.
Rolling Back Migrations
To rollback the latest migration operation, you may use the rollback command. This command rolls back the last 'batch' of migrations, which may include multiple migration files:
You may rollback a limited number of migrations by providing the step option to the rollback command. For example, the following command will rollback the last five migrations:
The migrate:reset command will roll back all of your application's migrations:
Rollback & Migrate In Single Command
The migrate:refresh command will roll back all of your migrations and then execute the migrate command. This command effectively re-creates your entire database:
You may rollback & re-migrate a limited number of migrations by providing the step option to the refresh command. For example, the following command will rollback & re-migrate the last five migrations:
Tables
Creating Tables
To create a new database table, use the create method on the Schema facade. Crypto key generate rsa general-keys label. The create method accepts two arguments. The first is the name of the table, while the second is a Closure which receives a Blueprint object that may be used to define the new table:
What Is Php Laravel
Of course, when creating the table, you may use any of the schema builder's column methods to define the table's columns.
Checking For Table / Column Existence
You may easily check for the existence of a table or column using the hasTable and hasColumn methods:
Connection & Storage Engine
If you want to perform a schema operation on a database connection that is not your default connection, use the connection method:
You may use the engine property on the schema builder to define the table's storage engine:
Renaming / Dropping Tables
To rename an existing database table, use the rename method:
To drop an existing table, you may use the drop or dropIfExists methods:
Renaming Tables With Foreign Keys
Before renaming a table, you should verify that any foreign key constraints on the table have an explicit name in your migration files instead of letting Laravel assign a convention based name. Otherwise, the foreign key constraint name will refer to the old table name.
Columns
Creating Columns
The table method on the Schema facade may be used to update existing tables. Like the create method, the table method accepts two arguments: the name of the table and a Closure that receives a Blueprint instance you may use to add columns to the table:
Available Column Types
Of course, the schema builder contains a variety of column types that you may specify when building your tables:
| Command | Description |
|---|---|
$table->bigIncrements('id'); | Incrementing ID (primary key) using a 'UNSIGNED BIG INTEGER' equivalent. |
$table->bigInteger('votes'); | BIGINT equivalent for the database. |
$table->binary('data'); | BLOB equivalent for the database. |
$table->boolean('confirmed'); | BOOLEAN equivalent for the database. |
$table->char('name', 4); | CHAR equivalent with a length. |
$table->date('created_at'); | DATE equivalent for the database. |
$table->dateTime('created_at'); | DATETIME equivalent for the database. |
$table->dateTimeTz('created_at'); | DATETIME (with timezone) equivalent for the database. |
$table->decimal('amount', 5, 2); | DECIMAL equivalent with a precision and scale. |
$table->double('column', 15, 8); | DOUBLE equivalent with precision, 15 digits in total and 8 after the decimal point. |
$table->enum('choices', ['foo', 'bar']); | ENUM equivalent for the database. |
$table->float('amount', 8, 2); | FLOAT equivalent for the database, 8 digits in total and 2 after the decimal point. |
$table->increments('id'); | Incrementing ID (primary key) using a 'UNSIGNED INTEGER' equivalent. |
$table->integer('votes'); | INTEGER equivalent for the database. |
$table->ipAddress('visitor'); | IP address equivalent for the database. |
$table->json('options'); | JSON equivalent for the database. |
$table->jsonb('options'); | JSONB equivalent for the database. |
$table->longText('description'); | LONGTEXT equivalent for the database. |
$table->macAddress('device'); | MAC address equivalent for the database. |
$table->mediumIncrements('id'); | Incrementing ID (primary key) using a 'UNSIGNED MEDIUM INTEGER' equivalent. |
$table->mediumInteger('numbers'); | MEDIUMINT equivalent for the database. |
$table->mediumText('description'); | MEDIUMTEXT equivalent for the database. |
$table->morphs('taggable'); | Adds unsigned INTEGER taggable_id and STRING taggable_type. |
$table->nullableMorphs('taggable'); | Nullable versions of the morphs() columns. |
$table->nullableTimestamps(); | Nullable versions of the timestamps() columns. |
$table->rememberToken(); | Adds remember_token as VARCHAR(100) NULL. |
$table->smallIncrements('id'); | Incrementing ID (primary key) using a 'UNSIGNED SMALL INTEGER' equivalent. |
$table->smallInteger('votes'); | SMALLINT equivalent for the database. |
$table->softDeletes(); | Adds nullable deleted_at column for soft deletes. |
$table->string('email'); | VARCHAR equivalent column. |
$table->string('name', 100); | VARCHAR equivalent with a length. |
$table->text('description'); | TEXT equivalent for the database. |
$table->time('sunrise'); | TIME equivalent for the database. |
$table->timeTz('sunrise'); | TIME (with timezone) equivalent for the database. |
$table->tinyInteger('numbers'); | TINYINT equivalent for the database. |
$table->timestamp('added_on'); | TIMESTAMP equivalent for the database. |
$table->timestampTz('added_on'); | TIMESTAMP (with timezone) equivalent for the database. |
$table->timestamps(); | Adds nullable created_at and updated_at columns. |
$table->timestampsTz(); | Adds nullable created_at and updated_at (with timezone) columns. |
$table->unsignedBigInteger('votes'); | Unsigned BIGINT equivalent for the database. |
$table->unsignedInteger('votes'); | Unsigned INT equivalent for the database. |
$table->unsignedMediumInteger('votes'); | Unsigned MEDIUMINT equivalent for the database. |
$table->unsignedSmallInteger('votes'); | Unsigned SMALLINT equivalent for the database. |
$table->unsignedTinyInteger('votes'); | Unsigned TINYINT equivalent for the database. |
$table->uuid('id'); | UUID equivalent for the database. |
Column Modifiers
In addition to the column types listed above, there are several column 'modifiers' you may use while adding a column to a database table. For example, to make the column 'nullable', you may use the nullable method:
Below is a list of all the available column modifiers. This list does not include the index modifiers:
| Modifier | Description |
|---|---|
->after('column') | Place the column 'after' another column (MySQL Only) |
->comment('my comment') | Add a comment to a column |
->default($value) | Specify a 'default' value for the column |
->first() | Place the column 'first' in the table (MySQL Only) |
->nullable() | Allow NULL values to be inserted into the column |
->storedAs($expression) | Create a stored generated column (MySQL Only) |
->unsigned() | Set integer columns to UNSIGNED |
->virtualAs($expression) | Create a virtual generated column (MySQL Only) |
Modifying Columns
Prerequisites
Before modifying a column, be sure to add the doctrine/dbal dependency to your composer.json file. The Doctrine DBAL library is used to determine the current state of the column and create the SQL queries needed to make the specified adjustments to the column:
Updating Column Attributes
The change method allows you to modify some existing column types to a new type or modify the column's attributes. For example, you may wish to increase the size of a string column. To see the change method in action, let's increase the size of the name column from 25 to 50:
Laravel Generate Based On Foreign Key Definition
We could also modify a column to be nullable:
{note} The following column types can not be 'changed': char, double, enum, mediumInteger, timestamp, tinyInteger, ipAddress, json, jsonb, macAddress, mediumIncrements, morphs, nullableMorphs, nullableTimestamps, softDeletes, timeTz, timestampTz, timestamps, timestampsTz, unsignedMediumInteger, unsignedTinyInteger, uuid.
Renaming Columns
To rename a column, you may use the renameColumn method on the Schema builder. Before renaming a column, be sure to add the doctrine/dbal dependency to your composer.json file:
{note} Renaming any column in a table that also has a column of type enum is not currently supported.
Dropping Columns
To drop a column, use the dropColumn method on the Schema builder. Before dropping columns from a SQLite database, you will need to add the doctrine/dbal dependency to your composer.json file and run the composer update command in your terminal to install the library:
You may drop multiple columns from a table by passing an array of column names to the dropColumn method:
{note} Dropping or modifying multiple columns within a single migration while using a SQLite database is not supported.
Indexes
Creating Indexes
The schema builder supports several types of indexes. First, let's look at an example that specifies a column's values should be unique. To create the index, we can simply chain the unique method onto the column definition:
Alternatively, you may create the index after defining the column. For example:
You may even pass an array of columns to an index method to create a compound index:
Laravel will automatically generate a reasonable index name, but you may pass a second argument to the method to specify the name yourself:
Available Index Types
Laravel Generate Based On Foreign Key Youtube
| Command | Description |
|---|---|
$table->primary('id'); | Add a primary key. |
$table->primary(['first', 'last']); | Add composite keys. |
$table->unique('email'); | Add a unique index. |
$table->unique('state', 'my_index_name'); | Add a custom index name. |
$table->unique(['first', 'last']); | Add a composite unique index. |
$table->index('state'); | Add a basic index. |
Dropping Indexes
To drop an index, you must specify the index's name. By default, Laravel automatically assigns a reasonable name to the indexes. Simply concatenate the table name, the name of the indexed column, and the index type. Here are some examples:
| Command | Description |
|---|---|
$table->dropPrimary('users_id_primary'); | Drop a primary key from the 'users' table. |
$table->dropUnique('users_email_unique'); | Drop a unique index from the 'users' table. |
$table->dropIndex('geo_state_index'); | Drop a basic index from the 'geo' table. |
If you pass an array of columns into a method that drops indexes, the conventional index name will be generated based on the table name, columns and key type:
Foreign Key Constraints
Laravel also provides support for creating foreign key constraints, which are used to force referential integrity at the database level. For example, let's define a user_id column on the posts table that references the id column on a users table:
You may also specify the desired action for the 'on delete' and 'on update' properties of the constraint:
To drop a foreign key, you may use the dropForeign method. Foreign key constraints use the same naming convention as indexes. So, we will concatenate the table name and the columns in the constraint then suffix the name with '_foreign':
Or, you may pass an array value which will automatically use the conventional constraint name when dropping:
You may enable or disable foreign key constraints within your migrations by using the following methods: