module Sequel::Oracle
Public Instance Methods
# File lib/sequel/adapters/shared/oracle.rb, line 287 def complex_expression_sql_append(sql, op, args) case op when :& complex_expression_arg_pairs_append(sql, args, &BITAND_PROC) when :| complex_expression_arg_pairs_append(sql, args){|a, b| Sequel.lit(["(", " - ", " + ", ")"], a, complex_expression_arg_pairs([a, b], &BITAND_PROC), b)} when :^ complex_expression_arg_pairs_append(sql, args) do |*x| s1 = complex_expression_arg_pairs(x){|a, b| Sequel.lit(["(", " - ", " + ", ")"], a, complex_expression_arg_pairs([a, b], &BITAND_PROC), b)} s2 = complex_expression_arg_pairs(x, &BITAND_PROC) Sequel.lit(["(", " - ", ")"], s1, s2) end when :%, :<<, :>>, :'B~' complex_expression_emulate_append(sql, op, args) else super end end
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.
# File lib/sequel/adapters/shared/oracle.rb, line 309 def constant_sql_append(sql, c) if c == :CURRENT_TIME super(sql, :CURRENT_TIMESTAMP) else super end end
Use a custom expression with EXISTS to determine whether a dataset is empty.
# File lib/sequel/adapters/shared/oracle.rb, line 325 def empty? db[:dual].where(@opts[:offset] ? exists : unordered.exists).get(1) == nil end
Oracle uses MINUS instead of EXCEPT, and doesn't support EXCEPT ALL
# File lib/sequel/adapters/shared/oracle.rb, line 318 def except(dataset, opts=OPTS) raise(Sequel::Error, "EXCEPT ALL not supported") if opts[:all] compound_clone(:minus, dataset, opts) end
Oracle requires recursive CTEs to have column aliases.
# File lib/sequel/adapters/shared/oracle.rb, line 373 def recursive_cte_requires_column_aliases? true end
Handle LIMIT by using a unlimited subselect filtered with ROWNUM.
# File lib/sequel/adapters/shared/oracle.rb, line 342 def select_sql return super if @opts[:sql] if o = @opts[:offset] columns = clone(:append_sql=>'', :placeholder_literal_null=>true).columns dsa1 = dataset_alias(1) rn = row_number_column limit = @opts[:limit] ds = unlimited. from_self(:alias=>dsa1). select_append(ROW_NUMBER_EXPRESSION.as(rn)). from_self(:alias=>dsa1). select(*columns). where(SQL::Identifier.new(rn) > o) ds = ds.where(SQL::Identifier.new(rn) <= Sequel.+(o, limit)) if limit sql = @opts[:append_sql] || '' subselect_sql_append(sql, ds) sql elsif limit = @opts[:limit] 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
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 337 def sequence(s) clone(:sequence=>s) end
# File lib/sequel/adapters/shared/oracle.rb, line 377 def supports_cte?(type=:select) type == :select end
Oracle does not support derived column lists
# File lib/sequel/adapters/shared/oracle.rb, line 382 def supports_derived_column_lists? false end
Oracle supports GROUP BY CUBE
# File lib/sequel/adapters/shared/oracle.rb, line 387 def supports_group_cube? true end
Oracle supports GROUP BY ROLLUP
# File lib/sequel/adapters/shared/oracle.rb, line 392 def supports_group_rollup? true end
Oracle does not support INTERSECT ALL or EXCEPT ALL
# File lib/sequel/adapters/shared/oracle.rb, line 397 def supports_intersect_except_all? false end
Oracle does not support IS TRUE.
# File lib/sequel/adapters/shared/oracle.rb, line 402 def supports_is_true? false end
Oracle does not support SELECT *, column
# File lib/sequel/adapters/shared/oracle.rb, line 417 def supports_select_all_and_column? false end
Oracle supports timezones in literal timestamps.
# File lib/sequel/adapters/shared/oracle.rb, line 422 def supports_timestamp_timezones? true end
Oracle does not support WHERE 'Y' for WHERE TRUE.
# File lib/sequel/adapters/shared/oracle.rb, line 427 def supports_where_true? false end
Oracle supports window functions
# File lib/sequel/adapters/shared/oracle.rb, line 432 def supports_window_functions? true end
Private Instance Methods
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 440 def as_sql_append(sql, aliaz, column_aliases=nil) raise Error, "oracle does not support derived column lists" if column_aliases sql << SPACE quote_identifier_append(sql, aliaz) end
The strftime format to use when literalizing the time.
# File lib/sequel/adapters/shared/oracle.rb, line 447 def default_timestamp_format TIMESTAMP_FORMAT end
# File lib/sequel/adapters/shared/oracle.rb, line 451 def empty_from_sql DUAL end
There is no function on Microsoft SQL Server that does character length and respects trailing spaces (datalength respects trailing spaces, but counts bytes instead of characters). Use a hack to work around the trailing spaces issue.
# File lib/sequel/adapters/shared/oracle.rb, line 459 def emulate_function?(name) name == :char_length end
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.
# File lib/sequel/adapters/shared/oracle.rb, line 468 def emulate_function_sql_append(sql, f) if f.name == :char_length literal_append(sql, Sequel::SQL::Function.new(:length, Sequel.join([f.args.first, 'x'])) - 1) end end
If this dataset is associated with a sequence, return the most recently inserted sequence value.
# File lib/sequel/adapters/shared/oracle.rb, line 476 def execute_insert(sql, opts=OPTS) f = @opts[:from] super(sql, {:table=>(f.first if f), :sequence=>@opts[:sequence]}.merge(opts)) end
Use a colon for the timestamp offset, since Oracle appears to require it.
# File lib/sequel/adapters/shared/oracle.rb, line 482 def format_timestamp_offset(hour, minute) sprintf(TIMESTAMP_OFFSET_FORMAT, hour, minute) end
Oracle doesn't support empty values when inserting.
# File lib/sequel/adapters/shared/oracle.rb, line 487 def insert_supports_empty_values? false end
Use string in hex format for blob data.
# File lib/sequel/adapters/shared/oracle.rb, line 492 def literal_blob_append(sql, v) sql << APOS << v.unpack(HSTAR).first << APOS end
Oracle uses 'N' for false values.
# File lib/sequel/adapters/shared/oracle.rb, line 497 def literal_false BOOL_FALSE end
Oracle uses 'Y' for true values.
# File lib/sequel/adapters/shared/oracle.rb, line 507 def literal_true BOOL_TRUE end
Oracle can insert multiple rows using a UNION
# File lib/sequel/adapters/shared/oracle.rb, line 512 def multi_insert_sql_strategy :union end
Oracle supports quoted function names.
# File lib/sequel/adapters/shared/oracle.rb, line 517 def supports_quoted_function_names? true end