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# frozen-string-literal: true
#
# The auto_cast_date_and_time extension uses SQL standard type casting
# when literalizing date, time, and timestamp values:
#
# DB.literal(Time.now)
# # => "TIMESTAMP '...'"
#
# DB.literal(Date.today)
# # => "DATE '...'"
#
# DB.literal(Sequel::SQLTime.create(10, 20, 30))
# # => "TIME '10:20:30.000000'"
#
# The default behavior of Sequel on adapters that do not require the
# SQL standard behavior is to format the date or time value without:
# casting
#
# DB.literal(Sequel::SQLTime.create(10, 20, 30))
# # => "'10:20:30.000000'"
#
# However, then the database cannot determine the type of the string,
# and must perform some implicit casting. If implicit casting cannot
# be used, it will probably treat the value as a string:
#
# DB.get(Time.now).class
# # Without auto_cast_date_and_time: String
# # With auto_cast_date_and_time: Time
#
# Note that not all databases support this extension. PostgreSQL and
# MySQL support it, but SQLite and Microsoft SQL Server do not.
#
# You can load this extension into specific datasets:
#
# ds = DB[:table]
# ds = ds.extension(:auto_cast_date_and_time)
#
# Or you can load it into all of a database's datasets, which
# is probably the desired behavior if you are using this extension:
#
# DB.extension(:auto_cast_date_and_time)
#
# Related module: Sequel::AutoCastDateAndTime
#
module Sequel
module AutoCastDateAndTime
# :nocov:
# Mark the datasets as requiring sql standard date times. This is only needed
# for backwards compatibility.
def requires_sql_standard_datetimes?
# SEQUEL6: Remove
true
end
# :nocov:
private
# Explicitly cast SQLTime objects to TIME.
def literal_sqltime_append(sql, v)
sql << "TIME "
super
end
# Explicitly cast Time objects to TIMESTAMP.
def literal_time_append(sql, v)
sql << literal_datetime_timestamp_cast
super
end
# Explicitly cast DateTime objects to TIMESTAMP.
def literal_datetime_append(sql, v)
sql << literal_datetime_timestamp_cast
super
end
# Explicitly cast Date objects to DATE.
def literal_date_append(sql, v)
sql << "DATE "
super
end
# The default cast string to use for Time/DateTime objects.
# Respects existing method if already defined.
def literal_datetime_timestamp_cast
return super if defined?(super)
'TIMESTAMP '
end
end
Dataset.register_extension(:auto_cast_date_and_time, AutoCastDateAndTime)
end
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