Module Sequel::MySQL::DatasetMethods
In: lib/sequel/adapters/shared/mysql.rb

Dataset methods shared by datasets that use MySQL databases.

Methods

Included Modules

Dataset::UnsupportedIntersectExcept

Constants

BOOL_TRUE = '1'.freeze
BOOL_FALSE = '0'.freeze
TIMESTAMP_FORMAT = "'%Y-%m-%d %H:%M:%S'".freeze
COMMA_SEPARATOR = ', '.freeze

Public Instance methods

MySQL specific syntax for LIKE/REGEXP searches, as well as string concatenation.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 197
197:       def complex_expression_sql(op, args)
198:         case op
199:         when :~, '!~''!~', '~*''~*', '!~*''!~*', :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
200:           "(#{literal(args.at(0))} #{'NOT ' if [:'NOT LIKE', :'NOT ILIKE', :'!~', :'!~*'].include?(op)}#{[:~, :'!~', :'~*', :'!~*'].include?(op) ? 'REGEXP' : 'LIKE'} #{'BINARY ' if [:~, :'!~', :LIKE, :'NOT LIKE'].include?(op)}#{literal(args.at(1))})"
201:         when '||''||'
202:           if args.length > 1
203:             "CONCAT(#{args.collect{|a| literal(a)}.join(', ')})"
204:           else
205:             literal(args.at(0))
206:           end
207:         else
208:           super(op, args)
209:         end
210:       end

MySQL supports ORDER and LIMIT clauses in DELETE statements.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 213
213:       def delete_sql
214:         sql = super
215:         sql << " ORDER BY #{expression_list(opts[:order])}" if opts[:order]
216:         sql << " LIMIT #{opts[:limit]}" if opts[:limit]
217:         sql
218:       end

MySQL doesn‘t support DISTINCT ON

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 221
221:       def distinct(*columns)
222:         raise(Error, "DISTINCT ON not supported by MySQL") unless columns.empty?
223:         super
224:       end

Adds full text filter

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 227
227:       def full_text_search(cols, terms, opts = {})
228:         filter(full_text_sql(cols, terms, opts))
229:       end

MySQL specific full text search syntax.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 232
232:       def full_text_sql(cols, term, opts = {})
233:         "MATCH #{literal(Array(cols))} AGAINST (#{literal(Array(term).join(' '))}#{" IN BOOLEAN MODE" if opts[:boolean]})"
234:       end

MySQL allows HAVING clause on ungrouped datasets.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 237
237:       def having(*cond, &block)
238:         _filter(:having, *cond, &block)
239:       end

MySQL doesn‘t use the SQL standard DEFAULT VALUES.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 242
242:       def insert_default_values_sql
243:         "INSERT INTO #{source_list(@opts[:from])} () VALUES ()"
244:       end

Sets up multi_insert or import to use INSERT IGNORE. Useful if you have a unique key and want to just skip inserting rows that violate the unique key restriction.

Example:

dataset.insert_ignore.multi_insert(

 [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]

)

INSERT IGNORE INTO tablename (name, value) VALUES (a, 1), (b, 2)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 276
276:       def insert_ignore
277:         clone(:insert_ignore=>true)
278:       end

Transforms an CROSS JOIN to an INNER JOIN if the expr is not nil. Raises an error on use of :full_outer type, since MySQL doesn‘t support it.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 248
248:       def join_table(type, table, expr=nil, table_alias={})
249:         type = :inner if (type == :cross) && !expr.nil?
250:         raise(Sequel::Error, "MySQL doesn't support FULL OUTER JOIN") if type == :full_outer
251:         super(type, table, expr, table_alias)
252:       end

Transforms :natural_inner to NATURAL LEFT JOIN and straight to STRAIGHT_JOIN.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 256
256:       def join_type_sql(join_type)
257:         case join_type
258:         when :straight then 'STRAIGHT_JOIN'
259:         when :natural_inner then 'NATURAL LEFT JOIN'
260:         else super
261:         end
262:       end

MySQL specific syntax for inserting multiple values at once.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 309
309:       def multi_insert_sql(columns, values)
310:         if update_cols = opts[:on_duplicate_key_update]
311:           update_cols = columns if update_cols.empty?
312:           update_string = update_cols.map{|c| "#{quote_identifier(c)}=VALUES(#{quote_identifier(c)})"}.join(COMMA_SEPARATOR)
313:         end
314:         values = values.map {|r| literal(Array(r))}.join(COMMA_SEPARATOR)
315:         ["INSERT#{' IGNORE' if opts[:insert_ignore]} INTO #{source_list(@opts[:from])} (#{identifier_list(columns)}) VALUES #{values}#{" ON DUPLICATE KEY UPDATE #{update_string}" if update_string}"]
316:       end

Sets up multi_insert or import to use ON DUPLICATE KEY UPDATE If you pass no arguments, ALL fields will be updated with the new values. If you pass the fields you want then ONLY those field will be updated.

Useful if you have a unique key and want to update inserting rows that violate the unique key restriction.

Examples:

dataset.on_duplicate_key_update.multi_insert(

 [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]

)

INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2) ON DUPLICATE KEY UPDATE name=VALUES(name), value=VALUES(value)

dataset.on_duplicate_key_update(:value).multi_insert(

 [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]

)

INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2) ON DUPLICATE KEY UPDATE value=VALUES(value)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 304
304:       def on_duplicate_key_update(*args)
305:         clone(:on_duplicate_key_update => args)
306:       end

MySQL uses the nonstandard ` (backtick) for quoting identifiers.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 319
319:       def quoted_identifier(c)
320:         "`#{c}`"
321:       end

MySQL specific syntax for REPLACE (aka UPSERT, or update if exists, insert if it doesn‘t).

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 325
325:       def replace_sql(*values)
326:         from = source_list(@opts[:from])
327:         if values.empty?
328:           "REPLACE INTO #{from} DEFAULT VALUES"
329:         else
330:           values = values[0] if values.size == 1
331:           
332:           case values
333:           when Array
334:             if values.empty?
335:               "REPLACE INTO #{from} DEFAULT VALUES"
336:             else
337:               "REPLACE INTO #{from} VALUES #{literal(values)}"
338:             end
339:           when Hash
340:             if values.empty?
341:               "REPLACE INTO #{from} DEFAULT VALUES"
342:             else
343:               fl, vl = [], []
344:               values.each {|k, v| fl << literal(k.is_a?(String) ? k.to_sym : k); vl << literal(v)}
345:               "REPLACE INTO #{from} (#{fl.join(COMMA_SEPARATOR)}) VALUES (#{vl.join(COMMA_SEPARATOR)})"
346:             end
347:           when Dataset
348:             "REPLACE INTO #{from} #{literal(values)}"
349:           else
350:             if values.respond_to?(:values)
351:               replace_sql(values.values)
352:             else  
353:               "REPLACE INTO #{from} VALUES (#{literal(values)})"
354:             end
355:           end
356:         end
357:       end

MySQL supports ORDER and LIMIT clauses in UPDATE statements.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 360
360:       def update_sql(values)
361:         sql = super
362:         sql << " ORDER BY #{expression_list(opts[:order])}" if opts[:order]
363:         sql << " LIMIT #{opts[:limit]}" if opts[:limit]
364:         sql
365:       end

[Validate]