fix(sql): add missing T-SQL keywords to sqlserver completion

apps/desktop/src/lib/sql/sqlCompletion.ts

@@ -534,6 +534,73 @@ const SQLSERVER_SQL_KEYWORDS = [
   "SHOWPLAN_ALL",
   "SHOWPLAN_TEXT",
   "SHOWPLAN_XML",
+  // T-SQL statements and control flow. `DECLARE` in particular is what issue #9319 reported:
+  // typing `decl` only offered `DECIMAL`, so scripting a batch had no completion at all.
+  "DECLARE",
+  "EXEC",
+  "EXECUTE",
+  "PRINT",
+  "RETURN",
+  "IF",
+  "WHILE",
+  "BREAK",
+  "CONTINUE",
+  "GOTO",
+  "WAITFOR",
+  "RAISERROR",
+  "THROW",
+  "TRY",
+  "CATCH",
+  "BEGIN TRY",
+  "BEGIN CATCH",
+  "BEGIN TRANSACTION",
+  "COMMIT TRANSACTION",
+  "ROLLBACK TRANSACTION",
+  "SAVE TRANSACTION",
+  "TRIGGER",
+  "PROCEDURE",
+  "FUNCTION",
+  "RETURNS",
+  "PIVOT",
+  "UNPIVOT",
+  "CROSS APPLY",
+  "OUTER APPLY",
+  "OPTION",
+  "RECOMPILE",
+  "MAXRECURSION",
+  // Frequently used T-SQL functions and session/system values. Built-in functions with
+  // parameter signatures (CONVERT, ISNULL, GETDATE, NEWID, STUFF, ...) are completed from
+  // SQLSERVER_FUNCTION_SIGNATURES instead; buildKeywordItems filters keywords that already
+  // have a signature, so they are not duplicated here. IIF has no SQL Server signature
+  // entry and is therefore listed as a keyword.
+  "IIF",
+  "CHOOSE",
+  "STRING_AGG",
+  "OBJECT_ID",
+  "SCOPE_IDENTITY",
+  "IDENT_CURRENT",
+  "SP_EXECUTESQL",
+  "SYSTEM_USER",
+  "SESSION_USER",
+  "CURRENT_USER",
+  "USER_NAME",
+  "SCHEMA_NAME",
+  "DATABASEPROPERTYEX",
+  "XACT_STATE",
+  "ERROR_MESSAGE",
+  "ERROR_NUMBER",
+  "ERROR_SEVERITY",
+  "ERROR_STATE",
+  "ERROR_LINE",
+  "ERROR_PROCEDURE",
+  "@@ERROR",
+  "@@IDENTITY",
+  "@@ROWCOUNT",
+  "@@TRANCOUNT",
+  "@@FETCH_STATUS",
+  "@@SERVERNAME",
+  "@@VERSION",
+  "@@SPID",
 ];
 
 function sqlDialectCompletionWords(...sources: Array<string | undefined>): string[] {