added sql handler

handle all sql operation
tester added
Merge remote-tracking branch 'origin/connection' into UI
Revert "update on ui look"

This reverts commit 171562e9e4cd7982ce827b1a81cef4d22836c3dd.
Revert "Revert "update on ui look""

This reverts commit c98dcc6f3f066cabff3de8aae77f52675fe4ec33.
Revert "Merge remote-tracking branch 'origin/connection' into UI"

This reverts commit aa1e1705a5666b226fca543c2ef3984724e83d2c, reversing
changes made to 171562e9e4cd7982ce827b1a81cef4d22836c3dd.