Module | Sequel::SQL::ComplexExpressionMethods
In: | lib/sequel/sql.rb

Adds methods that allow you to treat an object as an instance of a specific `ComplexExpression` subclass. This is useful if another library overrides the methods defined by Sequel.

For example, if `Symbol#/` is overridden to produce a string (for example, to make file system path creation easier), the following code will not do what you want:

      :price/10 > 100

In that case, you need to do the following:

      :price.sql_number/10 > 100

### Methods

extract sql_boolean sql_number sql_string

### Public Instance methods

extract(datetime_part)

Extract a datetime_part (e.g. year, month) from self:

      :date.extract(:year) # extract(year FROM "date")

Also has the benefit of returning the result as a NumericExpression instead of a generic ComplexExpression.

The extract function is in the SQL standard, but it doesn‘t doesn‘t use the standard function calling convention, and it doesn‘t work on all databases.

[Source]

         # File lib/sequel/sql.rb, line 323
    323:       def extract(datetime_part)
    324:         Function.new(:extract, PlaceholderLiteralString.new("#{datetime_part} FROM ?", [self])).sql_number
    325:       end

sql_boolean()

Return a BooleanExpression representation of `self`.

[Source]

         # File lib/sequel/sql.rb, line 328
    328:       def sql_boolean
    329:         BooleanExpression.new(:NOOP, self)
    330:       end

sql_number()

Return a NumericExpression representation of `self`.

      ~:a # NOT "a"
      ~:a.sql_number # ~"a"

[Source]

         # File lib/sequel/sql.rb, line 336
    336:       def sql_number
    337:         NumericExpression.new(:NOOP, self)
    338:       end

sql_string()

Return a StringExpression representation of `self`.

      :a + :b # "a" + "b"
      :a.sql_string + :b # "a" || "b"

[Source]

         # File lib/sequel/sql.rb, line 344
    344:       def sql_string
    345:         StringExpression.new(:NOOP, self)
    346:       end

[Validate]