Create a Table With Column of Type Array using Fluent Migrator in C#

PostgreSQL is a popular open-source database that is widely used by developers around the world. One of the powerful features of PostgreSQL is the support for arrays. An array is a collection of values of the same type, stored in a single column. This feature is useful in many scenarios, such as storing a list of tags, a list of email addresses, or a list of coordinates.

Fluent migrator is a .NET library that enables database schema migrations in a fluent and easy-to-use way. It supports many popular databases, including PostgreSQL. With Fluent migrator, you can create, modify, and delete tables, columns, indexes, and other database objects in a version-controlled and repeatable way. 

Creating a table in PostgreSQL database with Fluent Migrator is a simple task in C# code. However, if you need to add a column of type array such as TEXT[], the process may be a bit more complex. In this article, we will demonstrate how to create a table in a PostgreSQL database using Fluent migrator in C# code that has a column of type array such as TEXT[]. 

To get started, make sure you have a PostgreSQL database installed and a C# project that references the Fluent migrator library. You can install the library from the NuGet package manager by running the following command in the Package Manager Console:

Install-Package FluentMigrator.Postgres

Next, create a new migration class by inheriting from the Migration class and overriding the Up method. In this method, you will define the schema changes that you want to apply to the database. For example, here is a migration that creates a books table with an authors column of type array:

[Migration(20210527150000)]
public class CreateBooksTable : Migration
{
    public override void Up()
    {
        Create.Table("books")
            .WithColumn("id").AsInt32().PrimaryKey().Identity()
            .WithColumn("title").AsString()
            .WithColumn("authors").AsCustom("TEXT[]");

        // add other columns and indexes as needed
    }

    public override void Down()
    {
        Delete.Table("books");
    }
}

As you can see, we are using the Create.Table method to define the books table and its columns. The id column is defined as an integer primary key with auto-increment, the title column is defined as a string, and the authors column is defined as a custom type TEXT[].

Note that we are using the AsCustom method to specify the array type, as there is no built-in method for defining arrays in Fluent migrator. If you need to specify a non-text array type, you can use the corresponding type name, such as INTEGER[] or BOOLEAN[].

Once you have defined your migration class, you can run it by using the MigrateUp method of the MigrationRunner class, like this:

using FluentMigrator.Runner;
using FluentMigrator.Runner.Initialization;

var runner = new MigrationRunner(ConnectionString, new PostgresProcessorFactory());
runner.MigrateUp();

Here, ConnectionString is the connection string to your PostgreSQL database, and PostgresProcessorFactory is a factory class that creates the appropriate database processor for PostgreSQL.

Conclusion

You have now created a table in your PostgreSQL database with an array column using Fluent migrator in C# code. You can modify the migration class to add more columns, indexes, or constraints, and rerun the migration to apply the changes to the database. With Fluent migrator, you can easily manage your database schema and keep it in sync with your application code.