| Module | Sequel::Oracle::DatasetMethods |
| In: |
lib/sequel/adapters/shared/oracle.rb
|
| SELECT_CLAUSE_METHODS | = | Dataset.clause_methods(:select, %w'with select distinct columns from join where group having compounds order lock') |
| ROW_NUMBER_EXPRESSION | = | 'ROWNUM'.lit.freeze |
| SPACE | = | Dataset::SPACE |
| APOS | = | Dataset::APOS |
| APOS_RE | = | Dataset::APOS_RE |
| DOUBLE_APOS | = | Dataset::DOUBLE_APOS |
| FROM | = | Dataset::FROM |
| BITCOMP_OPEN | = | "((0 - ".freeze |
| BITCOMP_CLOSE | = | ") - 1)".freeze |
| ILIKE_0 | = | "(UPPER(".freeze |
| ILIKE_1 | = | ") ".freeze |
| ILIKE_2 | = | ' UPPER('.freeze |
| ILIKE_3 | = | "))".freeze |
| LIKE | = | 'LIKE'.freeze |
| NOT_LIKE | = | 'NOT LIKE'.freeze |
| TIMESTAMP_FORMAT | = | "TIMESTAMP '%Y-%m-%d %H:%M:%S%N %z'".freeze |
| TIMESTAMP_OFFSET_FORMAT | = | "%+03i:%02i".freeze |
| BOOL_FALSE | = | "'N'".freeze |
| BOOL_TRUE | = | "'Y'".freeze |
| HSTAR | = | "H*".freeze |
| DUAL | = | ['DUAL'.freeze].freeze |
Oracle needs to emulate bitwise operators and ILIKE/NOT ILIKE operators.
# File lib/sequel/adapters/shared/oracle.rb, line 205
205: def complex_expression_sql_append(sql, op, args)
206: case op
207: when :&
208: sql << complex_expression_arg_pairs(args){|a, b| "CAST(BITAND(#{literal(a)}, #{literal(b)}) AS INTEGER)"}
209: when :|
210: sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} - #{complex_expression_sql(:&, [a, b])} + #{literal(b)})"}
211: when :^
212: sql << complex_expression_arg_pairs(args){|*x| "(#{complex_expression_sql(:|, x)} - #{complex_expression_sql(:&, x)})"}
213: when 'B~''B~'
214: sql << BITCOMP_OPEN
215: literal_append(sql, args.at(0))
216: sql << BITCOMP_CLOSE
217: when :<<
218: sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} * power(2, #{literal b}))"}
219: when :>>
220: sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} / power(2, #{literal b}))"}
221: when :ILIKE, 'NOT ILIKE''NOT ILIKE'
222: sql << ILIKE_0
223: literal_append(sql, args.at(0))
224: sql << ILIKE_1
225: sql << (op == :ILIKE ? LIKE : NOT_LIKE)
226: sql<< ILIKE_2
227: literal_append(sql, args.at(1))
228: sql << ILIKE_3
229: else
230: super
231: end
232: 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 237
237: def constant_sql_append(sql, c)
238: if c == :CURRENT_TIME
239: super(sql, :CURRENT_TIMESTAMP)
240: else
241: super
242: end
243: end
Use a custom expression with EXISTS to determine whether a dataset is empty.
# File lib/sequel/adapters/shared/oracle.rb, line 254
254: def empty?
255: db[:dual].where(@opts[:offset] ? exists : unordered.exists).get(1) == nil
256: end
Oracle uses MINUS instead of EXCEPT, and doesn‘t support EXCEPT ALL
# File lib/sequel/adapters/shared/oracle.rb, line 246
246: def except(dataset, opts={})
247: opts = {:all=>opts} unless opts.is_a?(Hash)
248: raise(Sequel::Error, "EXCEPT ALL not supported") if opts[:all]
249: compound_clone(:minus, dataset, opts)
250: end
Handle LIMIT by using a unlimited subselect filtered with ROWNUM.
# File lib/sequel/adapters/shared/oracle.rb, line 271
271: def select_sql
272: if (limit = @opts[:limit]) && !@opts[:sql]
273: ds = clone(:limit=>nil)
274: # Lock doesn't work in subselects, so don't use a subselect when locking.
275: # Don't use a subselect if custom SQL is used, as it breaks somethings.
276: ds = ds.from_self unless @opts[:lock]
277: sql = @opts[:append_sql] || ''
278: subselect_sql_append(sql, ds.where(SQL::ComplexExpression.new(:<=, ROW_NUMBER_EXPRESSION, limit)))
279: sql
280: else
281: super
282: end
283: end