Module | Sequel::DB2::DatasetMethods
In: | lib/sequel/adapters/shared/db2.rb

### Methods

cast_sql_append complex_expression_sql_append supports_group_cube? supports_group_rollup? supports_is_true? supports_multiple_column_in? supports_select_all_and_column? supports_timestamp_usecs? supports_where_true? supports_window_functions?

### Included Modules

EmulateOffsetWithRowNumber

### Constants

PAREN_CLOSE | = | Dataset::PAREN_CLOSE
PAREN_OPEN | = | Dataset::PAREN_OPEN
BITWISE_METHOD_MAP | = | {:& =>:BITAND, :| => :BITOR, :^ => :BITXOR, :'B~'=>:BITNOT}
BOOL_TRUE | = | '1'.freeze
BOOL_FALSE | = | '0'.freeze
CAST_STRING_OPEN | = | "RTRIM(CHAR(".freeze
CAST_STRING_CLOSE | = | "))".freeze
FETCH_FIRST_ROW_ONLY | = | " FETCH FIRST ROW ONLY".freeze
FETCH_FIRST | = | " FETCH FIRST ".freeze
ROWS_ONLY | = | " ROWS ONLY".freeze
EMPTY_FROM_TABLE | = | ' FROM "SYSIBM"."SYSDUMMY1"'.freeze

### Public Instance methods

cast_sql_append(sql, expr, type)

DB2 casts strings using RTRIM and CHAR instead of VARCHAR.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 210
    210:       def cast_sql_append(sql, expr, type)
    211:         if(type == String)
    212:           sql << CAST_STRING_OPEN
    213:           literal_append(sql, expr)
    214:           sql << CAST_STRING_CLOSE
    215:         else
    216:           super
    217:         end
    218:       end

complex_expression_sql_append(sql, op, args)

Handle DB2 specific LIKE and bitwise operator support, and emulate the extract method, which DB2 doesn‘t natively support.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 222
    222:       def complex_expression_sql_append(sql, op, args)
    223:         case op
    224:         when :ILIKE
    225:           super(sql, :LIKE, [SQL::Function.new(:upper, args.at(0)), SQL::Function.new(:upper, args.at(1)) ])
    226:         when "NOT ILIKE""NOT ILIKE"
    227:           super(sql, "NOT LIKE""NOT LIKE", [SQL::Function.new(:upper, args.at(0)), SQL::Function.new(:upper, args.at(1)) ])
    228:         when :&, :|, :^
    229:           # works with db2 v9.5 and after
    230:           op = BITWISE_METHOD_MAP[op]
    231:           sql << complex_expression_arg_pairs(args){|a, b| literal(SQL::Function.new(op, a, b))}
    232:         when :<<
    233:           sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} * POWER(2, #{literal(b)}))"}
    234:         when :>>
    235:           sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} / POWER(2, #{literal(b)}))"}
    236:         when :%
    237:           sql << complex_expression_arg_pairs(args){|a, b| "MOD(#{literal(a)}, #{literal(b)})"}
    238:         when 'B~''B~'
    239:           literal_append(sql, SQL::Function.new(:BITNOT, *args))
    240:         when :extract
    241:           sql << args.at(0).to_s
    242:           sql << PAREN_OPEN
    243:           literal_append(sql, args.at(1))
    244:           sql << PAREN_CLOSE
    245:         else
    246:           super
    247:         end
    248:       end

supports_group_cube?()

DB2 supports GROUP BY CUBE

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 251
    251:       def supports_group_cube?
    252:         true
    253:       end

supports_group_rollup?()

DB2 supports GROUP BY ROLLUP

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 256
    256:       def supports_group_rollup?
    257:         true
    258:       end

supports_is_true?()

DB2 does not support IS TRUE.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 261
    261:       def supports_is_true?
    262:         false
    263:       end

supports_multiple_column_in?()

DB2 does not support multiple columns in IN.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 266
    266:       def supports_multiple_column_in?
    267:         false
    268:       end

supports_select_all_and_column?()

DB2 only allows * in SELECT if it is the only thing being selected.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 271
    271:       def supports_select_all_and_column?
    272:         false
    273:       end

supports_timestamp_usecs?()

DB2 does not support fractional seconds in timestamps.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 276
    276:       def supports_timestamp_usecs?
    277:         false
    278:       end

supports_where_true?()

DB2 does not support WHERE 1.

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 286
    286:       def supports_where_true?
    287:         false
    288:       end

supports_window_functions?()

DB2 supports window functions

[Source]

         # File lib/sequel/adapters/shared/db2.rb, line 281
    281:       def supports_window_functions?
    282:         true
    283:       end

[Validate]