lsp-sqls: Add lsp-sql-show-tables command (#4534)

CHANGELOG.org

@@ -9,6 +9,7 @@
   * Add support for C# via the [[https://github.com/dotnet/roslyn/tree/main/src/LanguageServer][Roslyn language server]].
   * Add basic support for [[https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_pullDiagnostics][pull diagnostics]] requests.
   * Add ~lsp-flush-delayed-changes-before-next-message~ customization point to enforce throttling document change notifications.
+  * Add ~lsp-sql-show-tables~ command.
   * Fix bug in ~rust-analyzer.check.features~ configuration via ~lsp-rust-checkonsave-features~ Emacs setting: we were defaulting to ~[]~, but ~rust-analyzer~ defaults to inheriting the value from ~rust-analyzer.cargo.features~. The bug resulted in code hidden behind features not getting type checked when those features were enabled by setting ~rust-analyzer.cargo.features~ via the ~lsp-rust-features~ Emacs setting.
   * Change ~ruff-lsp~ to ~ruff~ for python lsp client. All ~ruff-lsp~ customizable variable change to ~ruff~. Lsp server command now is ~["ruff" "server"]~ instead of ~["ruff-lsp"]~.
   * Add futhark support

clients/lsp-sqls.el

@@ -143,6 +143,14 @@ use the current region if set, otherwise the entire buffer."
     "workspace/executeCommand"
     (list :command "showConnections" :timeout lsp-sqls-timeout))))
 
+(defun lsp-sql-show-tables (&optional _command)
+  "Show tables."
+  (interactive)
+  (lsp-sqls--show-results
+   (lsp-request
+    "workspace/executeCommand"
+    (list :command "showTables" :timeout lsp-sqls-timeout))))
+
 (defun lsp-sql-switch-database (&optional _command)
   "Switch database."
   (interactive)
@@ -176,6 +184,7 @@ use the current region if set, otherwise the entire buffer."
                                        ("showDatabases" #'lsp-sql-show-databases)
                                        ("showSchemas" #'lsp-sql-show-schemas)
                                        ("showConnections" #'lsp-sql-show-connections)
+                                       ("showTables" #'lsp-sql-show-tables)
                                        ("switchDatabase" #'lsp-sql-switch-database)
                                        ("switchConnections" #'lsp-sql-switch-connection))
                   :server-id 'sqls