Class: DB::Features

Inherits:
Object
  • Object
show all
Defined in:
lib/db/features.rb

Overview

Standardized feature detection for database adapters. All features default to false, and adapters can enable specific capabilities.

Instance Method Summary collapse

Constructor Details

#initialize(**features) ⇒ Features

Returns a new instance of Features.



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# File 'lib/db/features.rb', line 10

def initialize(**features)
  @features = features
end

Instance Method Details

#alter_column_type? ⇒ Boolean

PostgreSQL-style column type modification: ALTER COLUMN name TYPE type USING expression.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 30

def alter_column_type?
  @features.fetch(:alter_column_type, false)
end

#auto_increment? ⇒ Boolean

MySQL-style AUTO_INCREMENT auto-increment columns.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 75

def auto_increment?
  @features.fetch(:auto_increment, false)
end

#batch_alter_table? ⇒ Boolean

Multiple operations can be combined in a single ALTER TABLE statement.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 55

def batch_alter_table?
  @features.fetch(:batch_alter_table, false)
end

#concurrent_schema? ⇒ Boolean

Support for concurrent/online schema changes.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 60

def concurrent_schema?
  @features.fetch(:concurrent_schema, false)
end

#conditional_operations? ⇒ Boolean

Support for IF EXISTS/IF NOT EXISTS clauses.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 45

def conditional_operations?
  @features.fetch(:conditional_operations, false)
end

#deferred_constraints? ⇒ Boolean

Support for adding constraints with validation deferred.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 65

def deferred_constraints?
  @features.fetch(:deferred_constraints, false)
end

#enabled?(feature) ⇒ Boolean

Check if a specific feature is enabled.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 15

def enabled?(feature)
  @features.fetch(feature, false)
end

#enabled_features ⇒ Object

Get all enabled features.



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# File 'lib/db/features.rb', line 20

def enabled_features
  @features.select{|_, enabled| enabled}.keys
end

#identity_columns? ⇒ Boolean

Support for IDENTITY columns (SQL Server/newer PostgreSQL).

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 85

def identity_columns?
  @features.fetch(:identity_columns, false)
end

#integer_primary_key_autoincrement? ⇒ Boolean

SQLite-style INTEGER PRIMARY KEY auto-increment.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 80

def integer_primary_key_autoincrement?
  @features.fetch(:integer_primary_key_autoincrement, false)
end

#modify_column? ⇒ Boolean

MySQL-style column modification: MODIFY COLUMN name type.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 35

def modify_column?
  @features.fetch(:modify_column, false)
end

#serial_columns? ⇒ Boolean

PostgreSQL-style SERIAL/BIGSERIAL auto-increment columns.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 70

def serial_columns?
  @features.fetch(:serial_columns, false)
end

#transactional_schema? ⇒ Boolean

Schema operations can be rolled back within transactions.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 50

def transactional_schema?
  @features.fetch(:transactional_schema, false)
end

#using_clause? ⇒ Boolean

Support for USING clause in column type changes.

Returns:

  • (Boolean) 


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# File 'lib/db/features.rb', line 40

def using_clause?
  @features.fetch(:using_clause, false)
end

#with(**additional_features) ⇒ Object

Create a new Features instance with additional or modified features.



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# File 'lib/db/features.rb', line 25

def with(**additional_features)
  self.class.new(**@features, **additional_features)
end