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PostgreSQL Fields

Here are some PostgreSQL-specific fields that extend the capabilities of relational databases with advanced data types and structures.

PGArrayField

The PGArrayField allows storing arrays of a given SQLAlchemy type in a single column. This is particularly useful for scenarios where you need to store lists of values without creating additional tables or using JSON fields.

How It Works

PGArrayField takes an SQLAlchemy type and creates an array of that type. This provides efficiency and flexibility when handling structured data that belongs to a single entity.

Example Usage

from typing import List
import sqlalchemy
import edgy

class MyModel(edgy.Model):
    data: List[str] = edgy.fields.PGArrayField(sqlalchemy.String(), default=list)
    ...

Explanation

  • PGArrayField(sqlalchemy.String()) defines an array of strings stored in a single column.
  • The default=list ensures that new instances of MyModel have an empty list if no value is provided.
  • This field is useful for cases where an entity naturally contains multiple values, such as a list of tags, keywords, or user preferences.

Benefits of Using PGArrayField

  • Efficiency: Avoids the need for additional tables and foreign key relationships when handling lists.
  • Query Performance: PostgreSQL provides optimized operators for querying arrays, making searches and filtering more efficient.
  • Flexibility: Can store various types (integers, strings, etc.) while still leveraging PostgreSQL's indexing and query capabilities.

Considerations

  • Indexing: PostgreSQL supports GIN indexes for array fields, which can significantly improve search performance.
  • Normalization: If an array contains frequently changing data or requires complex relationships, it might be better to store it in a separate table.

By using PGArrayField, you can efficiently manage structured data in PostgreSQL while maintaining the power and simplicity of relational models.