Module | Sequel::MSSQL::DatasetMethods
In: | lib/sequel/adapters/shared/mssql.rb

### Methods

aggregate_dataset complex_expression_sql constant_sql disable_insert_output disable_insert_output! fetch_rows full_text_search insert_select into multi_insert_sql nolock output output! quoted_identifier select_sql server_version supports_intersect_except? supports_is_true? supports_join_using? supports_modifying_joins? supports_multiple_column_in? supports_output_clause? supports_window_functions?

### Constants

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 distinct limit columns into from lock join where group having order compounds')
UPDATE_CLAUSE_METHODS | = | Dataset.clause_methods(:update, %w'with table set output from where')
NOLOCK | = | ' WITH (NOLOCK)'.freeze
UPDLOCK | = | ' WITH (UPDLOCK)'.freeze
WILDCARD | = | LiteralString.new('*').freeze
CONSTANT_MAP | = | {:CURRENT_DATE=>'CAST(CURRENT_TIMESTAMP AS DATE)'.freeze, :CURRENT_TIME=>'CAST(CURRENT_TIMESTAMP AS TIME)'.freeze}

### Public Instance methods

complex_expression_sql(op, args)

MSSQL uses + for string concatenation, and LIKE is case insensitive by default.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 215
    215:       def complex_expression_sql(op, args)
    216:         case op
    217:         when '||''||'
    218:           super(:+, args)
    219:         when :ILIKE
    220:           super(:LIKE, args)
    221:         when "NOT ILIKE""NOT ILIKE"
    222:           super("NOT LIKE""NOT LIKE", args)
    223:         when :<<
    224:           "(#{literal(args[0])} * POWER(2, #{literal(args[1])}))"
    225:         when :>>
    226:           "(#{literal(args[0])} / POWER(2, #{literal(args[1])}))"
    227:         else
    228:           super(op, args)
    229:         end
    230:       end

constant_sql(constant)

MSSQL doesn‘t support the SQL standard CURRENT_DATE or CURRENT_TIME

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 233
    233:       def constant_sql(constant)
    234:         CONSTANT_MAP[constant] || super
    235:       end

disable_insert_output()

Disable the use of INSERT OUTPUT

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 238
    238:       def disable_insert_output
    239:         clone(:disable_insert_output=>true)
    240:       end

disable_insert_output!()

Disable the use of INSERT OUTPUT, modifying the receiver

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 243
    243:       def disable_insert_output!
    244:         mutation_method(:disable_insert_output)
    245:       end

fetch_rows(sql) {|r| ...}

When returning all rows, if an offset is used, delete the row_number column before yielding the row.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 249
    249:       def fetch_rows(sql, &block)
    250:         @opts[:offset] ? super(sql){|r| r.delete(row_number_column); yield r} : super(sql, &block)
    251:       end

full_text_search(cols, terms, opts = {})

MSSQL uses the CONTAINS keyword for full text search

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 254
    254:       def full_text_search(cols, terms, opts = {})
    255:         filter("CONTAINS (#{literal(cols)}, #{literal(terms)})")
    256:       end

insert_select(*values)

Use the OUTPUT clause to get the value of all columns for the newly inserted record.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 259
    259:       def insert_select(*values)
    260:         return unless supports_output_clause?
    261:         naked.clone(default_server_opts(:sql=>output(nil, [:inserted.*]).insert_sql(*values))).single_record unless opts[:disable_insert_output]
    262:       end

into(table)

Specify a table for a SELECT … INTO query.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 265
    265:       def into(table)
    266:         clone(:into => table)
    267:       end

multi_insert_sql(columns, values)

MSSQL uses a UNION ALL statement to insert multiple values at once.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 270
    270:       def multi_insert_sql(columns, values)
    271:         [insert_sql(columns, LiteralString.new(values.map {|r| "SELECT #{expression_list(r)}" }.join(" UNION ALL ")))]
    272:       end

nolock()

Allows you to do a dirty read of uncommitted data using WITH (NOLOCK).

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 275
    275:       def nolock
    276:         lock_style(:dirty)
    277:       end

output(into, values)

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)

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 291
    291:       def output(into, values)
    292:         raise(Error, "SQL Server versions 2000 and earlier do not support the OUTPUT clause") unless supports_output_clause?
    293:         output = {}
    294:         case values
    295:           when Hash
    296:             output[:column_list], output[:select_list] = values.keys, values.values
    297:           when Array
    298:             output[:select_list] = values
    299:         end
    300:         output[:into] = into
    301:         clone({:output => output})
    302:       end

output!(into, values)

An output method that modifies the receiver.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 305
    305:       def output!(into, values)
    306:         mutation_method(:output, into, values)
    307:       end

quoted_identifier(name)

MSSQL uses [] to quote identifiers

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 310
    310:       def quoted_identifier(name)
    311:         "[#{name}]"
    312:       end

select_sql()

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 subselect which is selected from.

If offset is used, an order must be provided, because the use of ROW_NUMBER requires an order.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 324
    324:       def select_sql
    325:         return super unless o = @opts[:offset]
    326:         raise(Error, 'MSSQL requires an order be provided if using an offset') unless order = @opts[:order]
    327:         dsa1 = dataset_alias(1)
    328:         rn = row_number_column
    329:         subselect_sql(unlimited.
    330:           unordered.
    331:           select_append{ROW_NUMBER(:over, :order=>order){}.as(rn)}.
    332:           from_self(:alias=>dsa1).
    333:           limit(@opts[:limit]).
    334:           where(SQL::Identifier.new(rn) > o))
    335:       end

server_version()

The version of the database server.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 338
    338:       def server_version
    339:         db.server_version(@opts[:server])
    340:       end

supports_intersect_except?()

MSSQL 2005+ supports INTERSECT and EXCEPT

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 343
    343:       def supports_intersect_except?
    344:         is_2005_or_later?
    345:       end

supports_is_true?()

MSSQL does not support IS TRUE

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 348
    348:       def supports_is_true?
    349:         false
    350:       end

supports_join_using?()

MSSQL doesn‘t support JOIN USING

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 353
    353:       def supports_join_using?
    354:         false
    355:       end

supports_modifying_joins?()

MSSQL 2005+ supports modifying joined datasets

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 358
    358:       def supports_modifying_joins?
    359:         is_2005_or_later?
    360:       end

supports_multiple_column_in?()

MSSQL does not support multiple columns for the IN/NOT IN operators

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 363
    363:       def supports_multiple_column_in?
    364:         false
    365:       end

supports_output_clause?()

MSSQL 2005+ supports the output clause.

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 368
    368:       def supports_output_clause?
    369:         is_2005_or_later?
    370:       end

supports_window_functions?()

MSSQL 2005+ supports window functions

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 373
    373:       def supports_window_functions?
    374:         true
    375:       end

### Protected Instance methods

aggregate_dataset()

MSSQL does not allow ordering in sub-clauses unless ‘top’ (limit) is specified

[Source]

         # File lib/sequel/adapters/shared/mssql.rb, line 379
    379:       def aggregate_dataset
    380:         (options_overlap(Sequel::Dataset::COUNT_FROM_SELF_OPTS) && !options_overlap([:limit])) ? unordered.from_self : super
    381:       end

[Validate]