Class: DynamicMigrations::Postgres::Server::Database::Schema::Table

Inherits:
DynamicMigrations::Postgres::Server::Database::Source show all
Includes:
Columns, ForeignKeyConstraints, Indexes, Triggers, UniqueConstraints, Validations
Defined in:
lib/dynamic_migrations/postgres/server/database/schema/table.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/index.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/column.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/columns.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/indexes.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/trigger.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/triggers.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/validation.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/primary_key.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/validations.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/unique_constraint.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/unique_constraints.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/foreign_key_constraint.rb,
lib/dynamic_migrations/postgres/server/database/schema/table/foreign_key_constraints.rb

Overview

This class represents a postgres table.

Defined Under Namespace

Modules: Columns, ForeignKeyConstraints, Indexes, Triggers, UniqueConstraints, Validations Classes: Column, ExpectedSchemaError, ForeignKeyConstraint, Index, PrimaryKey, PrimaryKeyAlreadyExistsError, PrimaryKeyDoesNotExistError, Trigger, UniqueConstraint, Validation

Instance Attribute Summary collapse

Attributes inherited from DynamicMigrations::Postgres::Server::Database::Source

#source

Instance Method Summary collapse

Methods included from UniqueConstraints

#add_unique_constraint, #has_unique_constraint?, #unique_constraint, #unique_constraints, #unique_constraints_hash

Methods included from Triggers

#add_trigger, #has_trigger?, #trigger, #triggers, #triggers_hash

Methods included from ForeignKeyConstraints

#add_foreign_key_constraint, #add_remote_foreign_key_constraint, #foreign_key_constraint, #foreign_key_constraints, #foreign_key_constraints_hash, #has_foreign_key_constraint?

Methods included from Indexes

#add_index, #has_index?, #index, #indexes, #indexes_hash

Methods included from Validations

#add_validation, #has_validation?, #validation, #validations, #validations_hash

Methods included from Columns

#add_column, #column, #columns, #columns_hash, #has_column?

Methods inherited from DynamicMigrations::Postgres::Server::Database::Source

#assert_is_a_symbol!, #from_configuration?, #from_database?

Constructor Details

#initialize(source, schema, name, description: nil) ⇒ Table

initialize a new object to represent a postgres table

Raises:



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 32

def initialize source, schema, name, description: nil
  super source

  raise ExpectedSchemaError, schema unless schema.is_a? Schema
  @schema = schema

  raise ExpectedSymbolError, name unless name.is_a? Symbol
  @name = name

  unless description.nil?
    raise ExpectedStringError, description unless description.is_a? String
    @description = description.strip
    @description = nil if description == ""
  end

  @columns = {}
  @validations = {}
  @indexes = {}
  @foreign_key_constraints = {}
  @remote_foreign_key_constraints = []
  @triggers = {}
  @unique_constraints = {}
end

Instance Attribute Details

#description ⇒ Object (readonly)

Returns the value of attribute description.



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 28

def description
  @description
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 27

def name
  @name
end

#remote_foreign_key_constraints ⇒ Object (readonly)

Returns the value of attribute remote_foreign_key_constraints.



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 29

def remote_foreign_key_constraints
  @remote_foreign_key_constraints
end

#schema ⇒ Object (readonly)

Returns the value of attribute schema.



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 26

def schema
  @schema
end

Instance Method Details

#add_primary_key(name, column_names, **primary_key_options) ⇒ Object

add a primary key to this table

Raises:



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 62

def add_primary_key name, column_names, **primary_key_options
  raise PrimaryKeyAlreadyExistsError if @primary_key
  columns = column_names.map { |column_name| column column_name }
  @primary_key = PrimaryKey.new source, self, columns, name, **primary_key_options
end

#create_temp_table(connection, temp_table_name) ⇒ Object

Used within validations and triggers when normalizing check clauses and other SQL statements which require a table to process the SQL.

This method returns a hash representation of any temporary enums created to satisfy the columns in the table



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 87

def create_temp_table connection, temp_table_name
  # create the temp table and add the expected columns

  # if any of the columns are enums, then we need to create a temporary enum type for them.
  # we cant just create temporary columns as text fields because postgres may automatically
  # add casts to those columns, which would result in a different normalized check clause
  temp_enums = {}

  # an array of sql column definitions for within the create table SQL
  # we process each column individually like this so that we can create temporary enums for
  # any enum columns
  columns_sql = columns.map do |column|
    enum = column.enum
    if enum
      # create the temporary enum type
      temp_enum_name = "#{temp_table_name}_enum_#{temp_enums.count}"
      connection.exec("        CREATE TYPE \#{temp_enum_name} as ENUM ('\#{enum.values.join(\"','\")}');\n      SQL\n      temp_enums[temp_enum_name] = enum\n\n      # return the column definition used within the CREATE TABLE SQL\n      data_type = column.array? ? \"\#{temp_enum_name}[]\" : temp_enum_name\n      \"\\\"\#{column.name}\\\" \#{data_type}\"\n\n    else\n      # return the column definition used within the CREATE TABLE SQL\n      \"\\\"\#{column.name}\\\" \#{column.data_type}\"\n    end\n  end\n\n  # in case any of the columnbs are citext columns\n  connection.exec(\"CREATE EXTENSION IF NOT EXISTS citext;\")\n\n  # note, this is not actually a TEMP TABLE, it is created within a transaction\n  # and rolled back.\n  connection.exec(<<~SQL)\n    CREATE TABLE \#{temp_table_name} (\n      \#{columns_sql.join(\", \")}\n    );\n  SQL\n\n  temp_enums\nend\n")

#has_description? ⇒ Boolean

returns true if this table has a description, otehrwise false

Returns:

  • (Boolean) 


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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 57

def has_description?
  !@description.nil?
end

#has_primary_key? ⇒ Boolean

returns true if this table has a primary key, otherwise false

Returns:

  • (Boolean) 


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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 69

def has_primary_key?
  !@primary_key.nil?
end

#primary_key ⇒ Object

returns a primary key if one exists, else raises an error



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# File 'lib/dynamic_migrations/postgres/server/database/schema/table.rb', line 74

def primary_key
  pk = @primary_key
  unless pk
    raise PrimaryKeyDoesNotExistError
  end
  pk
end