Rails5 supports datetime with precision

[metaskills]

• Automatically use datetime2 when precision is used.
• Integration of datetime2 with type_to_sql so schema types are right.
• New subclasses for Table and TableDefinition with overhauled column methods.
• Fix our time fractional helpers to make datetime/datetime2 under full tests pass.
• New coerced tests.

[metaskills]

Some raw notes while I was working this.

# BEFORE
EXEC sp_executesql N'UPDATE [sst_datatypes] SET [datetime] = @0 WHERE [sst_datatypes].[id] = @1; SELECT @@ROWCOUNT AS AffectedRows', N'@0 datetime, @1 int', @0 = '04-01-2010 12:34:56.003', @1 = 1  [["datetime", "04-01-2010 12:34:56.003"], ["id", 1]]
EXEC sp_executesql N'SELECT  [sst_datatypes].* FROM [sst_datatypes] WHERE [sst_datatypes].[id] = @0  ORDER BY [sst_datatypes].[id] ASC OFFSET 0 ROWS FETCH NEXT @1 ROWS ONLY', N'@0 int, @1 int', @0 = 1, @1 = 1  [["id", 1], ["LIMIT", 1]]
EXEC sp_executesql N'SELECT  [sst_datatypes].* FROM [sst_datatypes] WHERE [sst_datatypes].[datetime] = @0  ORDER BY [sst_datatypes].[id] ASC OFFSET 0 ROWS FETCH NEXT @1 ROWS ONLY', N'@0 datetime, @1 int', @0 = '04-01-2010 12:34:56.003', @1 = 1  [["datetime", "04-01-2010 12:34:56.003"], ["LIMIT", 1]]

# AFTER
EXEC sp_executesql N'UPDATE [sst_datatypes] SET [datetime] = @0 WHERE [sst_datatypes].[id] = @1; SELECT @@ROWCOUNT AS AffectedRows', N'@0 datetime, @1 int', @0 = '04-01-2010 12:34:56.300', @1 = 1  [["datetime", "04-01-2010 12:34:56.300"], ["id", 1]]
IF @@TRANCOUNT > 0 ROLLBACK TRANSACTION
IF @@TRANCOUNT > 0 ROLLBACK TRANSACTION


def update_obj(obj, attr, tstring)
  sql = "UPDATE [sst_datatypes] SET [#{attr}] = '#{tstring}' WHERE [id] = #{obj.id};"
  connection.raw_connection.execute(sql).do
  sql = "SELECT [#{attr}] FROM [sst_datatypes] WHERE [id] = #{obj.id};"
  time = connection.select_value(sql)
  { usec: time.usec, nsec: time.nsec }
end

def update_obj2(obj, attr, tstring)
  c = connection.raw_connection
  sql = "UPDATE [sst_datatypes] SET [#{attr}] = '#{tstring}' WHERE [id] = #{obj.id};"
  c.execute(sql).do
  sql = "SELECT [#{attr}] FROM [sst_datatypes] WHERE [id] = #{obj.id};"
  time = c.execute(sql).each.first[attr.to_s]
  { usec: time.usec, nsec: time.nsec }
end

update_obj  obj, :datetime, '04-01-2010 12:34:56.300'
update_obj2 obj, :datetime, '04-01-2010 12:34:56.300'
=> {:usec=>300000, :nsec=>300000000}

update_obj  obj, :datetime, '01-01-1753 00:00:00.123'
update_obj2 obj, :datetime, '01-01-1753 00:00:00.123'
=> {:usec=>123000, :nsec=>123000000}

update_obj  obj, :datetime, '01-01-1753 00:00:00.003'
update_obj2 obj, :datetime, '01-01-1753 00:00:00.003'
=> {:usec=>3000, :nsec=>3000000}

c = connection.raw_connection
sql = "UPDATE [sst_datatypes] SET [datetime] = '04-01-2010 12:34:56.233' WHERE [id] = #{obj.id};"
c.execute(sql).each
sql = "UPDATE [sst_datatypes] SET [datetime] = '04-01-2010 12:34:56.234567' WHERE [id] = #{obj.id};"
c.execute(sql).each
# TinyTds::Error: Conversion failed when converting date and/or time from character string.

update_obj2 obj, :datetime2_7, '06-21-2008 13:30:00.000015'
=> {:usec=>15, :nsec=>15000}


def insert_obj(attr, tstring)
  con = @connection.raw_connection
  sql = "INSERT INTO [foos] ([#{attr}]) OUTPUT INSERTED.[id] VALUES ('#{tstring}');"
  id = con.execute(sql).each.first['id']
  sql = "SELECT [#{attr}] FROM [foos] WHERE [id] = #{id};"
  time = con.execute(sql).each.first[attr.to_s]
  { usec: time.usec, nsec: time.nsec }
end

insert_obj :created_at, '08-17-2014 12:30:00.9999'
=> {:usec=>0, :nsec=>0}
insert_obj :updated_at, '08-17-2014 12:30:00.9999'
=> {:usec=>999900, :nsec=>999900000}

c = @connection.raw_connection
c.execute("DELETE FROM [foos]").do
insert_obj :updated_at, '08-17-2014 12:30:00.9999'
=> {:usec=>999900, :nsec=>999900000}
sql = "SELECT [updated_at] FROM [foos] WHERE [updated_at] = '08-17-2014 12:30:00.9999';"
c.execute(sql).each.first['updated_at'].nsec
=> 999900000
sql = "SELECT [updated_at] FROM [foos] WHERE [updated_at] = '08-17-2014 12:30:00.999900000';"
c.execute(sql).each.first['updated_at'].nsec
=> 999900000
sql = "SELECT [updated_at] FROM [foos] WHERE [updated_at] = '08-17-2014 12:30:00.999900001';"
c.execute(sql).each.first['updated_at'].nsec
=> 999900000