Merge pull request #70 from tarasom/fix/sql-sum-empty-set

fix: Correct SUM() evaluation for empty result sets

Merge pull request #68 from tarasom/session_time_zone

feat: Add support for `@@session.time_zone` system variable

Merge pull request #67 from 1okey/least-psalm

Address psalm issues raised by the introduction of LEAST function

Merge pull request #65 from tarasom/convert_tz

feat: Add support for CONVERT_TZ() function

Merge pull request #63 from tarasom/timestampdiff_support

feat: Add support for TIMESTAMPDIFF() function

Merge pull request #62 from vimeo/support-null-value-comparision-in-m…

…in-max

Update Min & Max function to compare with null values.

Merge pull request #61 from vimeo/allows-double-negative

ensures double negative is evaluated correctly

Merge pull request #60 from vimeo/fix-limit-operation

fixes duplicate key error when limit operation is applied with UPDATE statement

Merge pull request #59 from vimeo/support-not-statements

fix the negation evaluations in fake sql

Merge pull request #48 from vimeo/make-sure-fetch-default-is-defined

Make Sure PDO::FETCH_DEFAULT is Defined