Module: ActiveRecord::ConnectionAdapters::PostgreSQL::SchemaStatements

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 285

def client_min_messages=(level)
  execute("SET client_min_messages TO '#{level}'", 'SCHEMA')
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 275

def schema_search_path
  @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0]
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 267

def schema_search_path=(schema_csv)
  if schema_csv
    execute("SET search_path TO #{schema_csv}", 'SCHEMA')
    @schema_search_path = schema_csv
  end
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 455

def change_column_default(table_name, column_name, default)
  clear_cache!
  column = column_for(table_name, column_name)
  return unless column

  alter_column_query = "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} %s"
  if default.nil?
    # <tt>DEFAULT NULL</tt> results in the same behavior as <tt>DROP DEFAULT</tt>. However, PostgreSQL will
    # cast the default to the columns type, which leaves us with a default like "default NULL::character varying".
    execute alter_column_query % "DROP DEFAULT"
  else
    execute alter_column_query % "SET DEFAULT #{quote_default_value(default, column)}"
  end
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 470

def change_column_null(table_name, column_name, null, default = nil)
  clear_cache!
  unless null || default.nil?
    column = column_for(table_name, column_name)
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote_default_value(default, column)} WHERE #{quote_column_name(column_name)} IS NULL") if column
  end
  execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 228

def collation
  query(<<-end_sql, 'SCHEMA')[0][0]
    SELECT pg_database.datcollate FROM pg_database WHERE pg_database.datname LIKE '#{current_database}'
  end_sql
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 195

def columns(table_name)
  # Limit, precision, and scale are all handled by the superclass.
  column_definitions(table_name).map do |column_name, type, default, notnull, oid, fmod|
    oid = get_oid_type(oid.to_i, fmod.to_i, column_name, type)
    default_value = extract_value_from_default(oid, default)
    default_function = extract_default_function(default_value, default)
    new_column(column_name, default_value, oid, type, notnull == 'f', default_function)
  end
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 54

def create_database(name, options = {})
  options = { encoding: 'utf8' }.merge!(options.symbolize_keys)

  option_string = options.inject("") do |memo, (key, value)|
    memo += case key
    when :owner
      " OWNER = \"#{value}\""
    when :template
      " TEMPLATE = \"#{value}\""
    when :encoding
      " ENCODING = '#{value}'"
    when :collation
      " LC_COLLATE = '#{value}'"
    when :ctype
      " LC_CTYPE = '#{value}'"
    when :tablespace
      " TABLESPACE = \"#{value}\""
    when :connection_limit
      " CONNECTION LIMIT = #{value}"
    else
      ""
    end
  end

  execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 253

def create_schema schema_name
  execute "CREATE SCHEMA #{schema_name}"
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 235

def ctype
  query(<<-end_sql, 'SCHEMA')[0][0]
    SELECT pg_database.datctype FROM pg_database WHERE pg_database.datname LIKE '#{current_database}'
  end_sql
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 210

def current_database
  query('select current_database()', 'SCHEMA')[0][0]
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 215

def current_schema
  query('SELECT current_schema', 'SCHEMA')[0][0]
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 124

alias data_source_exists? table_exists?

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 98

def data_sources # :nodoc
  select_values(<<-SQL, 'SCHEMA')
    SELECT c.relname
    FROM pg_class c
    LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
    WHERE c.relkind IN ('r', 'v','m') -- (r)elation/table, (v)iew, (m)aterialized view
    AND n.nspname = ANY (current_schemas(false))
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 258

def drop_schema schema_name
  execute "DROP SCHEMA #{schema_name} CASCADE"
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 126

def drop_table(table_name, options = {})
  execute "DROP TABLE #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}"
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 220

def encoding
  query(<<-end_sql, 'SCHEMA')[0][0]
    SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database
    WHERE pg_database.datname LIKE '#{current_database}'
  end_sql
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 501

def foreign_keys(table_name)
  fk_info = select_all <<-SQL.strip_heredoc
    SELECT t2.oid::regclass::text AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete
    FROM pg_constraint c
    JOIN pg_class t1 ON c.conrelid = t1.oid
    JOIN pg_class t2 ON c.confrelid = t2.oid
    JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
    JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
    JOIN pg_namespace t3 ON c.connamespace = t3.oid
    WHERE c.contype = 'f'
      AND t1.relname = #{quote(table_name)}
      AND t3.nspname = ANY (current_schemas(false))
    ORDER BY c.conname
  SQL

  fk_info.map do |row|
    options = {
      column: row['column'],
      name: row['name'],
      primary_key: row['primary_key']
    }

    options[:on_delete] = extract_foreign_key_action(row['on_delete'])
    options[:on_update] = extract_foreign_key_action(row['on_update'])

    ForeignKeyDefinition.new(table_name, row['to_table'], options)
  end
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 139

def index_name_exists?(table_name, index_name, default)
  exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
    SELECT COUNT(*)
    FROM pg_class t
    INNER JOIN pg_index d ON t.oid = d.indrelid
    INNER JOIN pg_class i ON d.indexrelid = i.oid
    WHERE i.relkind = 'i'
      AND i.relname = '#{index_name}'
      AND t.relname = '#{table_name}'
      AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) )
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 538

def index_name_length
  63
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 153

def indexes(table_name, name = nil)
   result = query(<<-SQL, 'SCHEMA')
     SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid
     FROM pg_class t
     INNER JOIN pg_index d ON t.oid = d.indrelid
     INNER JOIN pg_class i ON d.indexrelid = i.oid
     WHERE i.relkind = 'i'
       AND d.indisprimary = 'f'
       AND t.relname = '#{table_name}'
       AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) )
    ORDER BY i.relname
  SQL

  result.map do |row|
    index_name = row[0]
    unique = row[1] == 't'
    indkey = row[2].split(" ")
    inddef = row[3]
    oid = row[4]

    columns = Hash[query(<<-SQL, "SCHEMA")]
    SELECT a.attnum, a.attname
    FROM pg_attribute a
    WHERE a.attrelid = #{oid}
    AND a.attnum IN (#{indkey.join(",")})
    SQL

    column_names = columns.values_at(*indkey).compact

    unless column_names.empty?
      # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
      desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
      orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
      where = inddef.scan(/WHERE (.+)$/).flatten[0]
      using = inddef.scan(/USING (.+?) /).flatten[0].to_sym

      IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using)
    end
  end.compact
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 399

def primary_key(table)
  pks = exec_query(<<-end_sql, 'SCHEMA').rows
    SELECT attr.attname
    FROM pg_attribute attr
    INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = any(cons.conkey)
    WHERE cons.contype = 'p'
      AND cons.conrelid = '#{quote_table_name(table)}'::regclass
  end_sql
  return nil unless pks.count == 1
  pks[0][0]
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 495

def rename_index(table_name, old_name, new_name)
  validate_index_length!(table_name, new_name)

  execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 417

def rename_table(table_name, new_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
  pk, seq = pk_and_sequence_for(new_name)
  if seq && seq.identifier == "#{table_name}_#{pk}_seq"
    new_seq = "#{new_name}_#{pk}_seq"
    idx = "#{table_name}_pkey"
    new_idx = "#{new_name}_pkey"
    execute "ALTER TABLE #{quote_table_name(seq)} RENAME TO #{quote_table_name(new_seq)}"
    execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_table_name(new_idx)}"
  end

  rename_table_indexes(table_name, new_name)
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 131

def schema_exists?(name)
  exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
    SELECT COUNT(*)
    FROM pg_namespace
    WHERE nspname = '#{name}'
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 242

def schema_names
  query(<<-SQL, 'SCHEMA').flatten
    SELECT nspname
      FROM pg_namespace
     WHERE nspname !~ '^pg_.*'
       AND nspname NOT IN ('information_schema')
     ORDER by nspname;
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 298

def serial_sequence(table, column)
  result = exec_query(<<-eosql, 'SCHEMA')
    SELECT pg_get_serial_sequence('#{table}', '#{column}')
  eosql
  result.rows.first.first
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 111

def table_exists?(name)
  name = Utils.extract_schema_qualified_name(name.to_s)
  return false unless name.identifier

  exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
      SELECT COUNT(*)
      FROM pg_class c
      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
      WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view
      AND c.relname = '#{name.identifier}'
      AND n.nspname = #{name.schema ? "'#{name.schema}'" : 'ANY (current_schemas(false))'}
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 90

def tables(name = nil)
  query(<<-SQL, 'SCHEMA').map { |row| row[0] }
    SELECT tablename
    FROM pg_tables
    WHERE schemaname = ANY (current_schemas(false))
  SQL
end

# File 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb', line 543

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  case type.to_s
  when 'binary'
    # PostgreSQL doesn't support limits on binary (bytea) columns.
    # The hard limit is 1Gb, because of a 32-bit size field, and TOAST.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "No binary type has byte size #{limit}.")
    end
  when 'text'
    # PostgreSQL doesn't support limits on text columns.
    # The hard limit is 1Gb, according to section 8.3 in the manual.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "The limit on text can be at most 1GB - 1byte.")
    end
  when 'integer'
    return 'integer' unless limit

    case limit
      when 1, 2; 'smallint'
      when 3, 4; 'integer'
      when 5..8; 'bigint'
      else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with scale 0 instead.")
    end
  when 'datetime'
    return super unless precision

    case precision
      when 0..6; "timestamp(#{precision})"
      else raise(ActiveRecordError, "No timestamp type has precision of #{precision}. The allowed range of precision is from 0 to 6")
    end
  else
    super
  end
end