Module | Sequel::MSSQL::DatasetMethods |
In: |
lib/sequel/adapters/shared/mssql.rb
|
BOOL_TRUE | = | '1'.freeze |
BOOL_FALSE | = | '0'.freeze |
COMMA_SEPARATOR | = | ', '.freeze |
DELETE_CLAUSE_METHODS | = | Dataset.clause_methods(:delete, %w'with from output from2 where') |
INSERT_CLAUSE_METHODS | = | Dataset.clause_methods(:insert, %w'with into columns output values') |
SELECT_CLAUSE_METHODS | = | Dataset.clause_methods(:select, %w'with limit distinct columns from table_options join where group order having compounds') |
UPDATE_CLAUSE_METHODS | = | Dataset.clause_methods(:update, %w'with table set output from where') |
WILDCARD | = | LiteralString.new('*').freeze |
CONSTANT_MAP | = | {:CURRENT_DATE=>'CAST(CURRENT_TIMESTAMP AS DATE)'.freeze, :CURRENT_TIME=>'CAST(CURRENT_TIMESTAMP AS TIME)'.freeze} |
MSSQL uses + for string concatenation, and LIKE is case insensitive by default.
# File lib/sequel/adapters/shared/mssql.rb, line 192 192: def complex_expression_sql(op, args) 193: case op 194: when '||''||' 195: super(:+, args) 196: when :ILIKE 197: super(:LIKE, args) 198: when "NOT ILIKE""NOT ILIKE" 199: super("NOT LIKE""NOT LIKE", args) 200: else 201: super(op, args) 202: end 203: end
Disable the use of INSERT OUTPUT
# File lib/sequel/adapters/shared/mssql.rb, line 211 211: def disable_insert_output 212: clone(:disable_insert_output=>true) 213: end
Disable the use of INSERT OUTPUT, modifying the receiver
# File lib/sequel/adapters/shared/mssql.rb, line 216 216: def disable_insert_output! 217: mutation_method(:disable_insert_output) 218: end
When returning all rows, if an offset is used, delete the row_number column before yielding the row.
# File lib/sequel/adapters/shared/mssql.rb, line 222 222: def fetch_rows(sql, &block) 223: @opts[:offset] ? super(sql){|r| r.delete(row_number_column); yield r} : super(sql, &block) 224: end
Use the OUTPUT clause to get the value of all columns for the newly inserted record.
# File lib/sequel/adapters/shared/mssql.rb, line 232 232: def insert_select(*values) 233: naked.clone(default_server_opts(:sql=>output(nil, [:inserted.*]).insert_sql(*values))).single_record unless opts[:disable_insert_output] 234: end
Include an OUTPUT clause in the eventual INSERT, UPDATE, or DELETE query.
The first argument is the table to output into, and the second argument is either an Array of column values to select, or a Hash which maps output column names to selected values, in the style of insert or update.
Output into a returned result set is not currently supported.
Examples:
dataset.output(:output_table, [:deleted__id, :deleted__name]) dataset.output(:output_table, :id => :inserted__id, :name => :inserted__name)
# File lib/sequel/adapters/shared/mssql.rb, line 258 258: def output(into, values) 259: output = {} 260: case values 261: when Hash 262: output[:column_list], output[:select_list] = values.keys, values.values 263: when Array 264: output[:select_list] = values 265: end 266: output[:into] = into 267: clone({:output => output}) 268: end
MSSQL Requires the use of the ROW_NUMBER window function to emulate an offset. This implementation requires MSSQL 2005 or greater (offset can‘t be emulated well in MSSQL 2000).
The implementation is ugly, cloning the current dataset and modifying the clone to add a ROW_NUMBER window function (and some other things), then using the modified clone in a CTE which is selected from.
If offset is used, an order must be provided, because the use of ROW_NUMBER requires an order.
# File lib/sequel/adapters/shared/mssql.rb, line 290 290: def select_sql 291: return super unless o = @opts[:offset] 292: raise(Error, 'MSSQL requires an order be provided if using an offset') unless order = @opts[:order] 293: dsa1 = dataset_alias(1) 294: dsa2 = dataset_alias(2) 295: rn = row_number_column 296: unlimited. 297: unordered. 298: from_self(:alias=>dsa2). 299: select{[WILDCARD, ROW_NUMBER(:over, :order=>order){}.as(rn)]}. 300: from_self(:alias=>dsa1). 301: limit(@opts[:limit]). 302: where(rn > o). 303: select_sql 304: end
The version of the database server.
# File lib/sequel/adapters/shared/mssql.rb, line 307 307: def server_version 308: db.server_version(@opts[:server]) 309: end