These new functions are to support MBQL's is-null and is-empty.

Use the compact syntax tree in the type checker to easily constrain the
type for each argument in a function/case expression. This will lead to
a correct resolve for every dimension/metric/segment in that subtree
associated with each argument.

* Custom expression: build a compact version of the syntax tree

The Chevrotain-based parser produces a very verbose syntax tree
(matching the grammar productions on every step of the way).
For instance, a custom expression as simple as "1" results in
the following tree:

```
(root)
  expression
    relationalExpression
      additionExpression
        multiplicationExpression
          atomicExpression
            numberLiteral
```

This makes it hard for type-checker to perform its analysis, due to the
need to traverse deeply every one of its children (even if there is only
one direct child).

The compact syntax tree can be constructed from the above
representation, which trims the unnecessary intermediate nodes:

```
(root)
  numberLiteral
```

Since it is used a placeholder for a dimension, a metric, or a segment
(resolving to one of them is delegated to the compiler), it makes sense
to use a more generic and less confusing name.

The core logic of MBQL compiler only has an abstract understanding of
the environment access (fields like segments, dimensions, and metrics)
as resolving those can be delegated accordingly.

As a bonus, this makes it very easy to test and to refactor the compiler
code.

The previous grammar revamp finally allowed some complex expression
constructs.

* Revamp the grammar of custom expression

Handle logical operations (AND, OR, NOT) by having them as part of the
grammar productions/rules, instead of only as special cases of
filters/aggregations.

This finally allows any arithmetic operations inside a filter. In fact,
this lets the correct mix-up between any logical and arithmetic
operations (including function calls), also by leveraging the type
checker to determine the correct type constraints for the terminals (Booleans,
expressions, dimensions, metrics, segments, etc).

* Be more explicit about skipped (known) regression

Use the type-checker to dynamically resolve dimensions as metrics,
wherever it is constrained in the right sub-tree for an aggregation.

Use the type checker for dynamic resolving of an identifier, i.e. to infer
whether it represents a dimension or a segment, based on the type
constraints in the sub-expression.
This also eliminates the flawed type-based resolving which happens
during the parsing time.

* Add a barebone type checker for the expression parser

* Add more context and other review feedback

* Custom expression parser: formalize the tree visitor

Also included, a pretty-printer to debug the syntax tree.

* Simplify the tree's pretty printer

Switch query execution to use `Statement` instead of `PreparedStatement` when there are no params

Add new multimethod to create a `Statement`, rather than `PreparedStatement`, which works similarly, called `statement`

Add new multimethod to run a SQL query against a Statement, similar to `execute-query!`, called `execute-statement!`

For consistency, rename `execute-query!` to `execute-prepared-statement!`

Change `execute-reducible-query` to capture whether the query has params, and if not, using the new multimethods instead

Update fetch-results-metadata-test so it replaces execute-select! instead of prepared-statement

Adding `statement-supported?` multimethod (defaults to true), to let drivers control whether statements are used at all

Updating Oracle driver to not override holdability for `statement`, similar to `prepared-statement`, and bumping module version

Updating SparkSQL driver to indicate that statements are not supported, and bumping module version

Fixing Redshift test to also override `execute-statement!` so it can capture the SQL for a statement

* Adding the ability to sync admin groups in EE

Adds a LDAP setting for EE to enable to LDAP Administrator group syncs.

Adds the setting to admin UI to enable syncing of the admin group.

Removes two unused settings from the OSS side.

metabase/metabase-enterprise#445

* Apply suggestions from code review

Co-authored-by: Dalton <daltojohnso@users.noreply.github.com>

Co-authored-by: Dalton <daltojohnso@users.noreply.github.com>

Modifying ddl.clj to account for a difference in behavior for honeysql.helpers/columns introduced in honeysql 0.9.7 (see long comment)

* Combine search scores into one weighted number

* Use richer representation of scores

Should make the FE debugging bits more robust

* Upgrade React to v16

* Upgrade react-hot-loader

* Use portal in BodyComponent (#14779)

* Use portal in Popover (#14799)

* Use portal in Popover

* Use SandboxedPortal to stop portal child/parent event propagation

React portals bubble events from component childrent to component
parents _through_ the portal as though they are attached. This breaks
our Triggerable HOC that wraps everything in an anchor tag -- click
events inside of an open Popover trigger the "toggle" function in
Triggerable, closing the Popover component.

Adding an additional div to the code potentially breaks styling, but
this seemed better than the alternative of changing/limiting
Triggerable.

* Fix adding of open class

* don't trigger some logic when popover is not open

* change wrapper span to a div

* rmv explicit bind from handleDismissal fn

* add comment explaining reasoning for SandboxedPortal

* add comment to explain need for 'maxHeight' state value

* Use ReactDOMServer to render html in a contenteditable div (#14869)

As part of the react v16 we can no longer rely on a synchronous
ReactDOM.render call. Using the third arg callback of ReactDOM.render
does not work for reasons unknown to me, but it would likely be
race-condition-y anyways due to this being an input field. I'm using
ReactDOMServer in order to avoid rewriting the react TokenizedExpression
component as html and to avoid associated xss vulnerabilities, etc.

* Rename unsafe lifecycles (#14887)

* Rename unsafe lifecycles

* Fix flow error: Remove unused suppressions

* use SandboxedPortal in Modal (#14905)

* use SandboxedPortal in Modal

* Move modal append container to constructor

This breaks the entry animation but it fixes problems with having a
popover _inside_ of the modal. Previously, popover was appending its
container el before the modal, causing a stacking issue.

* remove unstable_renderSubtreeIntoContainer from Tooltip (#14976)

Co-authored-by: Dalton <daltojohnso@users.noreply.github.com>

* fix default SearcbResult item layout and icon shrinking

* tweak text

* Add an error from SQLite

* Update docs/troubleshooting-guide/running.md

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

* Added identification of users and processes and explained myself a bit more on the running metabase troubleshooting guide

* Update docs/troubleshooting-guide/docker.md

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

* Update docs/troubleshooting-guide/running.md

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

* Update docs/troubleshooting-guide/docker.md

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

* Update 05-setting-permissions.md

Adding a few words about raw query permissions

* Update docs/administration-guide/05-setting-permissions.md

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

Co-authored-by: Jeff Bruemmer <jeff@metabase.com>

1. Rename optimize-datetime-filters middleware -> optimize-temporal-filters (it's more accurate, because this also
optimizes date or time filter clauses)

2. optimize-temporal-filters middleware now optimizes relative-datetime clauses (which represent a moment in time
relative to when the query is ran, e.g. "last month") in addition to absolute-datetime clauses (which represent an
absolute moment in time, e.g. 2021-02-15T14:40:00-08:00) . This middleware rewrites queries so we filter against
specific temporal ranges without casting the column itself, meaning we can leverage indexes on that column. See #11837
for more details

3. Added new validate-temporal-bucketing middleware that throws an Exception if you try to do something that makes no
sense, e.g. bucket a DATE field by :time or a TIME field by :month. This is a better situation then running the query
and waiting for the DB to complain. (In practice, I don't think the FE client would let you generate a query like this
in the first place)

4. Fix random test failures for MySQL in task-history-cleanup-test

* Implement ssh tunnel reconnection

From the connection-with-timezone method of execute, check whether an ssh tunnel that should be open actually is not, and if so, mark the entire pool as invalid (thereby forcing the connection code to rebuild the source and open a new tunnel)

Fixing the create-pool! function so that the relevant ssh tunnel entries are kept (in addition to the :datasource)

Adding test in ssh-test namespace, which will test that the tunnel is reestablished (for now, running with Postgres driver)

* Responding to PR feedback from Dan

* Fixing test by adding AcceptAllForwardingFilter forwardingFilter to the mock password server instance

* Change with-driver to test-driver

* Add ssh tunnel reconnect test that can run against H2

* Implement ssh tunnel reconnection

From the connection-with-timezone method of execute, check whether an ssh tunnel that should be open actually is not, and if so, mark the entire pool as invalid (thereby forcing the connection code to rebuild the source and open a new tunnel)

Fixing the create-pool! function so that the relevant ssh tunnel entries are kept (in addition to the :datasource)

Adding test in ssh-test namespace, which will test that the tunnel is reestablished (for now, running with Postgres driver)

* Responding to PR feedback from Dan

* Fixing test by adding AcceptAllForwardingFilter forwardingFilter to the mock password server instance

* Rebase again to fix merge conflict

* Change test-driver to with-driver in hopes of making CodeCov finally happy

* Adding new multimethod to ssh namespace, called incorporate-ssh-tunnel-details, for accounting for the

Implementing incorporate-ssh-tunnel-details for h2 so update the URI string (:db key) to point to the tunnel entry point

Pulled logic for :sql-jdbc implementation of connection-with-timezone out to a new fn, so it can be called elsewhere

Updating H2 reconnection test imn light of the changes above

Added "!" suffix to name of include-ssh-tunnel to reflect the fact that it does modify global state

* Fixing NPE in incorporate-ssh-tunnel-details implementation for :h2

Moving multimethod declaration for incorporate-ssh-tunnel-details to driver namespace

* Fix :h2 implementation again

* Remove another errant extra line :(

* Rebase onto master

* Inline the private helper fn back into connection-with-timezone

* Remove dead code

Background

The original version of MBQL (known as the "Structured Query" language at the time, which was a little confusing) just referred to all fields by integer ID. e.g.

{:filter ["STARTS_WITH" 1 "abc"]}
That made clauses like this ambiguous:

{:filter ["=" 1 2]} ; is 2 a Field, or the number 2?
To clear up ambiguity and to let you filter Fields against Fields, we added the :field-id clause to make it explicit that you were referring to a Field, not an Integer:

{:filter [:= [:field-id 1] [:field-id 2]]} ; Field 1 == Field 2
We soon added a couple of new types of Field clauses, :fk-> and :datetime-field, both of which wrap the original :field-id:

;; refer to Field 2 from a different Table, use Field 1 from the current Table to perform the join
[:fk-> [:field-id 1] [:field-id 2]]

;; bucket Field 3 by month
[:datetime-field [:field 3] :month]
So far things were still pretty reasonable, the worst you'd have to do is something like

[:datetime-field [:fk-> [:field-id 1] [:field-id 2]] :month]
Things started to get out-of-hand IMO when we continued to add more Field clause types that just wrapped everything else. We added :binning-strategy:

[:binning-strategy <field> :num-buckets 10]
then :field-literal, to refer to a Field from a nested native source query:

[:field-literal "my_field" :type/Text]
then we added :joined-field to specify the Table you're explicitly joining against that is the source of a Field:

[:joined-field "my_join" [:field-id 4]]
This ends up getting really hairy when you combine things. This is an actual real clause you can use right now:

[:binning-strategy
 [:datetime-field
  [:joined-field "my_join"
   [:field-literal "my_field" :type/DateTimeWithLocalTZ]]
  :month]
 :num-bins 10]
And even with all of those clauses, we still can't pass around arbitrary extra information in a way that would make it easy to implement performance optimizations. If we ever try to add another new clause, the whole house of cards is going to come crashing down.

The proposal
Combine all of the Field clauses into a single new :field clauses with the schema

[:field id-or-name options-map]
Here are some before & after examples:

[:field-id 1] 
=> 
[:field 1 nil]

[:field-literal "my_field" :type/Text] 
=> 
[:field "my_field" {:base-type :type/Text}]

[:datetime-field [:field 1] :month] 
=> 
[:field 1 {:temporal-unit :month}]

[:binning-strategy [:field 1] :num-bins 10] 
=>
[:field 1 {:binning {:strategy :num-bins, :num-bins 10}}]

[:joined-field "my_join" [:field 1]] 
=> 
[:field 1 {:join-alias "my_join}]

[:fk-> [:field 1] [:field 2]] 
=> 
[:field 2 {:source-field 1}]

[:binning-strategy
 [:datetime-field
  [:joined-field "my_join"
   [:field-literal "my_field" :type/DateTimeWithLocalTZ]]
  :month]
 :num-bins 10]
=>
[:field "my_field" {:base-type :type/DateTimeWithLocalTZ, :join-alias "my_join", :binning {:strategy :num-bins, :num-bins 10}}]

* Use dashboard count in search scoring

[Fixes #14945]

* Fix sorting priority bug

(thanks, Dan!)

* Show (hidden) scores in search results for debugging purposes

* Bump memory limit for SQL Server on CI

c.f. https://metaboat.slack.com/archives/C5XHN8GLW/p1614272426000400

* basic no results styling

* tweaks

Per Kyle's suggestion

* Refactor various bits of search

* Prioritize pinned items in search results

[Fixes #14936]