Class: Dbviewer::Database::MetadataManager

Inherits:
Object
  • Object
show all
Defined in:
lib/dbviewer/database/metadata_manager.rb

Overview

MetadataManager handles retrieving and managing table structure information

Instance Method Summary collapse

Constructor Details

#initialize(connection, cache_manager) ⇒ MetadataManager

Initialize with a connection and cache manager

Parameters:

  • connection (ActiveRecord::ConnectionAdapters::AbstractAdapter) —

    Database connection

  • cache_manager (Dbviewer::Database::CacheManager) —

    Cache manager instance



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# File 'lib/dbviewer/database/metadata_manager.rb', line 8

def initialize(connection, cache_manager)
  @connection = connection
  @cache_manager = cache_manager
end

Instance Method Details

#column_exists?(table_name, column_name) ⇒ Boolean

Check if a column exists in a table

Parameters:

  • table_name (String) —

    Name of the table

  • column_name (String) —

    Name of the column

Returns:

  • (Boolean) —

    true if column exists, false otherwise



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# File 'lib/dbviewer/database/metadata_manager.rb', line 66

def column_exists?(table_name, column_name)
  columns = table_columns(table_name)
  columns.any? { |col| col[:name].to_s == column_name.to_s }
end

#fetch_foreign_keys(table_name) ⇒ Array<Hash>

Get foreign keys

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (Array<Hash>) —

    List of foreign keys with details



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# File 'lib/dbviewer/database/metadata_manager.rb', line 87

def fetch_foreign_keys(table_name)
  @connection.foreign_keys(table_name).map do |fk|
    {
      name: fk.name,
      from_table: fk.from_table,
      to_table: fk.to_table,
      column: fk.column,
      primary_key: fk.primary_key
    }
  end
end

#fetch_indexes(table_name) ⇒ Array<Hash>

Get table indexes

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (Array<Hash>) —

    List of indexes with details



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# File 'lib/dbviewer/database/metadata_manager.rb', line 74

def fetch_indexes(table_name)
  @connection.indexes(table_name).map do |index|
    {
      name: index.name,
      columns: index.columns,
      unique: index.unique
    }
  end
end

#fetch_reverse_foreign_keys(table_name) ⇒ Array<Hash>

Get reverse foreign keys (tables that reference this table)

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (Array<Hash>) —

    List of reverse foreign keys with details



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# File 'lib/dbviewer/database/metadata_manager.rb', line 102

def fetch_reverse_foreign_keys(table_name)
  tables
    .reject { |other_table| other_table == table_name }
    .flat_map do |other_table|
      @connection.foreign_keys(other_table)
        .select { |fk| fk.to_table == table_name }
        .map do |fk|
          {
            name: fk.name,
            from_table: fk.from_table,
            to_table: fk.to_table,
            column: fk.column,
            primary_key: fk.primary_key,
            relationship_type: "has_many"
          }
        end
    end
end

#primary_key(table_name) ⇒ String?

Get the primary key of a table

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (String, nil) —

    Primary key column name or nil if not found



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# File 'lib/dbviewer/database/metadata_manager.rb', line 55

def primary_key(table_name)
  @connection.primary_key(table_name)
rescue => e
  Rails.logger.error("[DBViewer] Error retrieving primary key for table #{table_name}: #{e.message}")
  nil
end

#table_columns(table_name) ⇒ Array<Hash>

Get column information for a table

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (Array<Hash>) —

    List of column details



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# File 'lib/dbviewer/database/metadata_manager.rb', line 22

def table_columns(table_name)
  # Cache columns for longer since schema changes are infrequent
  @cache_manager.fetch("columns-#{table_name}", expires_in: 600) do
    @connection.columns(table_name).map do |column|
      {
        name: column.name,
        type: column.type,
        null: column.null,
        default: column.default,
        primary: column.name == primary_key(table_name)
      }
    end
  end
end

#table_metadata(table_name) ⇒ Hash

Get detailed metadata about a table

Parameters:

  • table_name (String) —

    Name of the table

Returns:

  • (Hash) —

    Table metadata



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# File 'lib/dbviewer/database/metadata_manager.rb', line 40

def table_metadata(table_name)
  # Cache metadata for longer since schema relationships change infrequently
  @cache_manager.fetch("metadata-#{table_name}", expires_in: 600) do
    {
      primary_key: primary_key(table_name),
      indexes: fetch_indexes(table_name),
      foreign_keys: fetch_foreign_keys(table_name),
      reverse_foreign_keys: fetch_reverse_foreign_keys(table_name)
    }
  end
end

#tables ⇒ Array<String>

Get all tables in the database

Returns:

  • (Array<String>) —

    List of table names



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# File 'lib/dbviewer/database/metadata_manager.rb', line 15

def tables
  @connection.tables.sort
end