module Sequel::Oracle::DatasetMethods

Constants

APOS
APOS_RE
BITCOMP_CLOSE
BITCOMP_OPEN
BOOL_FALSE
BOOL_TRUE
DOUBLE_APOS
DUAL
FROM
HSTAR
ROW_NUMBER_EXPRESSION
SELECT_CLAUSE_METHODS
SPACE
TIMESTAMP_FORMAT
TIMESTAMP_OFFSET_FORMAT

Public Instance Methods

complex_expression_sql_append(sql, op, args) click to toggle source
Calls superclass method
# File lib/sequel/adapters/shared/oracle.rb, line 243
def complex_expression_sql_append(sql, op, args)
  case op
  when :&
    sql << complex_expression_arg_pairs(args){|a, b| "CAST(BITAND(#{literal(a)}, #{literal(b)}) AS INTEGER)"}
  when :|
    sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} - #{complex_expression_sql(:&, [a, b])} + #{literal(b)})"}
  when :^
    sql << complex_expression_arg_pairs(args){|*x| "(#{complex_expression_sql(:|, x)} - #{complex_expression_sql(:&, x)})"}
  when :'B~'
    sql << BITCOMP_OPEN
    literal_append(sql, args.at(0))
    sql << BITCOMP_CLOSE
  when :<<
    sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} * power(2, #{literal b}))"}
  when :>>
    sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} / power(2, #{literal b}))"}
  when :%
    sql << complex_expression_arg_pairs(args){|a, b| "MOD(#{literal(a)}, #{literal(b)})"}
  else
    super
  end
end
constant_sql_append(sql, c) click to toggle source

Oracle doesn't support CURRENT_TIME, as it doesn't have a type for storing just time values without a date, so use CURRENT_TIMESTAMP in its place.

Calls superclass method
# File lib/sequel/adapters/shared/oracle.rb, line 269
def constant_sql_append(sql, c)
  if c == :CURRENT_TIME
    super(sql, :CURRENT_TIMESTAMP)
  else
    super
  end
end
empty?() click to toggle source

Use a custom expression with EXISTS to determine whether a dataset is empty.

# File lib/sequel/adapters/shared/oracle.rb, line 300
def empty?
  db[:dual].where(@opts[:offset] ? exists : unordered.exists).get(1) == nil
end
emulated_function_sql_append(sql, f) click to toggle source

Oracle treats empty strings like NULL values, and doesn't support char_length, so make char_length use length with a nonempty string. Unfortunately, as Oracle treats the empty string as NULL, there is no way to get trim to return an empty string instead of nil if the string only contains spaces.

Calls superclass method
# File lib/sequel/adapters/shared/oracle.rb, line 282
def emulated_function_sql_append(sql, f)
  case f.f
  when :char_length
    literal_append(sql, Sequel::SQL::Function.new(:length, Sequel.join([f.args.first, 'x'])) - 1)
  else
    super
  end
end
except(dataset, opts={}) click to toggle source

Oracle uses MINUS instead of EXCEPT, and doesn't support EXCEPT ALL

# File lib/sequel/adapters/shared/oracle.rb, line 292
def except(dataset, opts={})
  opts = {:all=>opts} unless opts.is_a?(Hash)
  raise(Sequel::Error, "EXCEPT ALL not supported") if opts[:all]
  compound_clone(:minus, dataset, opts)
end
recursive_cte_requires_column_aliases?() click to toggle source

Oracle requires recursive CTEs to have column aliases.

# File lib/sequel/adapters/shared/oracle.rb, line 332
def recursive_cte_requires_column_aliases?
  true
end
requires_sql_standard_datetimes?() click to toggle source

Oracle requires SQL standard datetimes

# File lib/sequel/adapters/shared/oracle.rb, line 305
def requires_sql_standard_datetimes?
  true
end
select_sql() click to toggle source

Handle LIMIT by using a unlimited subselect filtered with ROWNUM.

# File lib/sequel/adapters/shared/oracle.rb, line 317
def select_sql
  if (limit = @opts[:limit]) && !@opts[:sql]
    ds = clone(:limit=>nil)
    # Lock doesn't work in subselects, so don't use a subselect when locking.
    # Don't use a subselect if custom SQL is used, as it breaks somethings.
    ds = ds.from_self unless @opts[:lock]
    sql = @opts[:append_sql] || ''
    subselect_sql_append(sql, ds.where(SQL::ComplexExpression.new(:<=, ROW_NUMBER_EXPRESSION, limit)))
    sql
  else
    super
  end
end
sequence(s) click to toggle source

Create a copy of this dataset associated to the given sequence name, which will be used when calling insert to find the most recently inserted value for the sequence.

# File lib/sequel/adapters/shared/oracle.rb, line 312
def sequence(s)
  clone(:sequence=>s)
end
supports_group_cube?() click to toggle source

Oracle supports GROUP BY CUBE

# File lib/sequel/adapters/shared/oracle.rb, line 337
def supports_group_cube?
  true
end
supports_group_rollup?() click to toggle source

Oracle supports GROUP BY ROLLUP

# File lib/sequel/adapters/shared/oracle.rb, line 342
def supports_group_rollup?
  true
end
supports_intersect_except_all?() click to toggle source

Oracle does not support INTERSECT ALL or EXCEPT ALL

# File lib/sequel/adapters/shared/oracle.rb, line 347
def supports_intersect_except_all?
  false
end
supports_is_true?() click to toggle source

Oracle does not support IS TRUE.

# File lib/sequel/adapters/shared/oracle.rb, line 352
def supports_is_true?
  false
end
supports_select_all_and_column?() click to toggle source

Oracle does not support SELECT *, column

# File lib/sequel/adapters/shared/oracle.rb, line 357
def supports_select_all_and_column?
  false
end
supports_timestamp_timezones?() click to toggle source

Oracle supports timezones in literal timestamps.

# File lib/sequel/adapters/shared/oracle.rb, line 362
def supports_timestamp_timezones?
  true
end
supports_where_true?() click to toggle source

Oracle does not support WHERE 'Y' for WHERE TRUE.

# File lib/sequel/adapters/shared/oracle.rb, line 367
def supports_where_true?
  false
end
supports_window_functions?() click to toggle source

Oracle supports window functions

# File lib/sequel/adapters/shared/oracle.rb, line 372
def supports_window_functions?
  true
end

Private Instance Methods

as_sql_append(sql, aliaz) click to toggle source

Oracle doesn't support the use of AS when aliasing a dataset. It doesn't require the use of AS anywhere, so this disables it in all cases.

# File lib/sequel/adapters/shared/oracle.rb, line 380
def as_sql_append(sql, aliaz)
  sql << SPACE
  quote_identifier_append(sql, aliaz)
end
default_timestamp_format() click to toggle source

The strftime format to use when literalizing the time.

# File lib/sequel/adapters/shared/oracle.rb, line 386
def default_timestamp_format
  TIMESTAMP_FORMAT
end
execute_insert(sql, opts={}) click to toggle source

If this dataset is associated with a sequence, return the most recently inserted sequence value.

Calls superclass method
# File lib/sequel/adapters/shared/oracle.rb, line 392
def execute_insert(sql, opts={})
  f = @opts[:from]
  super(sql, {:table=>(f.first if f), :sequence=>@opts[:sequence]}.merge(opts))
end
format_timestamp_offset(hour, minute) click to toggle source

Use a colon for the timestamp offset, since Oracle appears to require it.

# File lib/sequel/adapters/shared/oracle.rb, line 398
def format_timestamp_offset(hour, minute)
  sprintf(TIMESTAMP_OFFSET_FORMAT, hour, minute)
end
insert_supports_empty_values?() click to toggle source

Oracle doesn't support empty values when inserting.

# File lib/sequel/adapters/shared/oracle.rb, line 403
def insert_supports_empty_values?
  false
end
literal_blob_append(sql, v) click to toggle source

Use string in hex format for blob data.

# File lib/sequel/adapters/shared/oracle.rb, line 408
def literal_blob_append(sql, v)
  sql << APOS << v.unpack(HSTAR).first << APOS
end
literal_false() click to toggle source

Oracle uses 'N' for false values.

# File lib/sequel/adapters/shared/oracle.rb, line 413
def literal_false
  BOOL_FALSE
end
literal_string_append(sql, v) click to toggle source

Oracle uses the SQL standard of only doubling ' inside strings.

# File lib/sequel/adapters/shared/oracle.rb, line 418
def literal_string_append(sql, v)
  sql << APOS << v.gsub(APOS_RE, DOUBLE_APOS) << APOS
end
literal_true() click to toggle source

Oracle uses 'Y' for true values.

# File lib/sequel/adapters/shared/oracle.rb, line 423
def literal_true
  BOOL_TRUE
end
select_clause_methods() click to toggle source

Use the Oracle-specific SQL clauses (no limit, since it is emulated).

# File lib/sequel/adapters/shared/oracle.rb, line 428
def select_clause_methods
  SELECT_CLAUSE_METHODS
end
select_from_sql(sql) click to toggle source

Modify the SQL to add the list of tables to select FROM Oracle doesn't support select without FROM clause so add the dummy DUAL table if the dataset doesn't select from a table.

# File lib/sequel/adapters/shared/oracle.rb, line 436
def select_from_sql(sql)
  sql << FROM
  source_list_append(sql, @opts[:from] || DUAL)
end