Class | Sequel::Postgres::PGRowOp |
In: |
lib/sequel/extensions/pg_row_ops.rb
|
Parent: | SQL::PlaceholderLiteralString |
OPEN | = | '('.freeze |
CLOSE_DOT | = | ').'.freeze |
CLOSE_STAR | = | '.*)'.freeze |
CLOSE_STAR_CAST | = | '.*)::'.freeze |
EMPTY | = | "".freeze |
ROW | = | [OPEN, CLOSE_STAR].freeze |
ROW_CAST | = | [OPEN, CLOSE_STAR_CAST].freeze |
QUALIFY | = | [OPEN, CLOSE_DOT].freeze |
WRAP | = | [EMPTY].freeze |
Use the (identifier).* syntax to reference the members of the composite type as separate columns. Generally used when you want to expand the columns of a composite type to be separate columns in the result set.
Sequel.pg_row_op(:a).* # (a).* Sequel.pg_row_op(:a)[:b].* # ((a).b).*
# File lib/sequel/extensions/pg_row_ops.rb, line 123 123: def *(ce=(arg=false;nil)) 124: if arg == false 125: Sequel::SQL::ColumnAll.new([self]) 126: else 127: super(ce) 128: end 129: end
Access a member of the composite type if given a symbol or an SQL::Identifier. For all other access, assuming the pg_array_ops extension is loaded and that it represents an array access. In either case, return a PgRowOp so that access can be cascaded.
# File lib/sequel/extensions/pg_row_ops.rb, line 107 107: def [](member) 108: case member 109: when Symbol, SQL::Identifier 110: PGRowOp.new(QUALIFY, [self, member]) 111: else 112: PGRowOp.wrap(Sequel.pg_array_op(self)[member]) 113: end 114: end
Use the (identifier.*) syntax to indicate that this expression represents the composite type of one of the tables being referenced, if it has the same name as one of the columns. If the cast_to argument is given, also cast the expression to that type (which should be a symbol representing the composite type). This is used if you want to return whole table row as a composite type.
Sequel.pg_row_op(:a).splat[:b] # (a.*).b Sequel.pg_row_op(:a).splat(:a) # (a.*)::a
# File lib/sequel/extensions/pg_row_ops.rb, line 142 142: def splat(cast_to=nil) 143: if args.length > 1 144: raise Error, 'cannot splat a PGRowOp with multiple arguments' 145: end 146: 147: if cast_to 148: PGRowOp.new(ROW_CAST, args + [cast_to]) 149: else 150: PGRowOp.new(ROW, args) 151: end 152: end