Represents a SQL expression, with a given operator and one or more attributes (which may also be ComplexExpressions, forming a tree). This class is the backbone of Sequel’s ruby expression DSL.
This is an abstract class that is not that useful by itself. The subclasses BooleanExpression, NumericExpression, and StringExpression define the behavior of the DSL via operators.
Included modules
Constants
| ASSOCIATIVE_OPERATORS | = | [:AND, :OR, :'||', :+, :*, :&, :|].freeze |
Operator symbols that are associative |
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| BITWISE_OPERATORS | = | [:&, :|, :^, :<<, :>>, :%].freeze |
Bitwise mathematical operators used in |
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| BOOLEAN_OPERATOR_METHODS | = | {:& => :AND, :| =>:OR}.freeze |
Hash of ruby operator symbols to |
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| CONSTANT_INVERSIONS | = | {Constants::TRUE=>Constants::FALSE, Constants::FALSE=>Constants::TRUE, Constants::NULL=>Constants::NOTNULL, Constants::NOTNULL=>Constants::NULL}.freeze |
A hash of the opposite for each constant, used for inverting constants. |
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| CUSTOM_EXPRESSIONS | = | [:extract].freeze |
Custom expressions that may have different syntax on different databases |
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| EQUALITY_OPERATORS | = | [:'=', :'!='].freeze |
Operators that check for equality |
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| INEQUALITY_OPERATORS | = | [:<, :>, :<=, :>=].freeze |
Inequality operators used in |
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| IN_OPERATORS | = | [:IN, :'NOT IN'].freeze |
Operators that use IN/NOT IN for inclusion/exclusion |
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| IS_OPERATORS | = | [:IS, :'IS NOT'].freeze |
Operators that use IS, used for special casing to override literal true/false values |
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| LIKE_OPERATORS | = | [:LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE'].freeze |
Operators that do pattern matching via LIKE |
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| MATHEMATICAL_OPERATORS | = | [:+, :-, :/, :*, :**].freeze |
Standard mathematical operators used in |
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| N_ARITY_OPERATORS | = | ([:AND, :OR, :'||'] + MATHEMATICAL_OPERATORS + BITWISE_OPERATORS - [:**]).freeze |
Operator symbols that take one or more arguments |
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| ONE_ARITY_OPERATORS | = | [:NOT, :NOOP, :'B~'].freeze |
Operator symbols that take only a single argument |
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| OPERATOR_INVERSIONS | = | {:AND => :OR, :OR => :AND, :< => :>=, :> => :<=, :<= => :>, :>= => :<, :'=' => :'!=' , :'!=' => :'=', :LIKE => :'NOT LIKE', :'NOT LIKE' => :LIKE, :~ => :'!~', :'!~' => :~, :IN => :'NOT IN', :'NOT IN' => :IN, :IS => :'IS NOT', :'IS NOT' => :IS, :'~*' => :'!~*', :'!~*' => :'~*', :NOT => :NOOP, :NOOP => :NOT, :ILIKE => :'NOT ILIKE', :'NOT ILIKE'=>:ILIKE}.freeze |
A hash of the opposite for each operator symbol, used for inverting objects. |
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| OPERTATOR_INVERSIONS | = | OPERATOR_INVERSIONS |
SEQUEL6: Remove |
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| REGEXP_OPERATORS | = | [:~, :'!~', :'~*', :'!~*'].freeze |
Operators that do pattern matching via regular expressions |
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| TWO_ARITY_OPERATORS | = | (EQUALITY_OPERATORS + INEQUALITY_OPERATORS + IS_OPERATORS + IN_OPERATORS + REGEXP_OPERATORS + LIKE_OPERATORS + [:**]).freeze |
Operator symbols that take exactly two arguments |
Public Class methods
Set the operator symbol and arguments for this object to the ones given. Convert all args that are hashes or arrays of two element arrays to BooleanExpressions, other than the second arg for an IN/NOT IN operator. Raise an Error if the operator doesn’t allow boolean input and a boolean argument is given. Raise an Error if the wrong number of arguments for a given operator is used.
# File lib/sequel/sql.rb 219 def initialize(op, *args) 220 orig_args = args 221 args = args.map{|a| Sequel.condition_specifier?(a) ? SQL::BooleanExpression.from_value_pairs(a) : a} 222 case op 223 when *N_ARITY_OPERATORS 224 raise(Error, "The #{op} operator requires at least 1 argument") unless args.length >= 1 225 args.map!{|a| a.is_a?(self.class) && a.op == :NOOP ? a.args.first : a} 226 if ASSOCIATIVE_OPERATORS.include?(op) 227 old_args = args 228 args = [] 229 old_args.each{|a| a.is_a?(self.class) && a.op == op ? args.concat(a.args) : args.push(a)} 230 end 231 when *TWO_ARITY_OPERATORS 232 raise(Error, "The #{op} operator requires precisely 2 arguments") unless args.length == 2 233 # With IN/NOT IN, even if the second argument is an array of two element arrays, 234 # don't convert it into a boolean expression, since it's definitely being used 235 # as a value list. 236 args[1] = orig_args[1] if IN_OPERATORS.include?(op) 237 when *ONE_ARITY_OPERATORS 238 raise(Error, "The #{op} operator requires a single argument") unless args.length == 1 239 when *CUSTOM_EXPRESSIONS 240 # nothing 241 else 242 raise(Error, "Invalid operator #{op}") 243 end 244 @op = op 245 @args = args.freeze 246 freeze 247 end
Public Instance methods
Return a BooleanExpression with the same op and args.
# File lib/sequel/sql.rb 1275 def sql_boolean 1276 BooleanExpression.new(op, *args) 1277 end
Return a NumericExpression with the same op and args.
# File lib/sequel/sql.rb 1280 def sql_number 1281 NumericExpression.new(op, *args) 1282 end
Return a StringExpression with the same op and args.
# File lib/sequel/sql.rb 1285 def sql_string 1286 StringExpression.new(op, *args) 1287 end