YQL-19747: Support USE statement

Introduce global analysis which will be extended with more ParseTree analysis later.

---

- Related to `YQL-19747`
- Related to https://github.com/vityaman/ydb/issues/40

---

Pull Request resolved: https://github.com/ytsaurus/ytsaurus/pull/1281
commit_hash:848fb3fdd6bc9612769c47d66198fca018ff465f

1 files changed, 63 insertions, 0 deletions

diff --git a/yql/essentials/sql/v1/complete/sql_complete_ut.cpp b/yql/essentials/sql/v1/complete/sql_complete_ut.cpp
index 1e01f899e46..00c5f3427f6 100644
--- a/yql/essentials/sql/v1/complete/sql_complete_ut.cpp
+++ b/yql/essentials/sql/v1/complete/sql_complete_ut.cpp
@@ -604,6 +604,69 @@ Y_UNIT_TEST_SUITE(SqlCompleteTests) {
         }
     }
 
+    Y_UNIT_TEST(SelectFromWithUse) {
+        auto engine = MakeSqlCompletionEngineUT();
+        {
+            TVector<TCandidate> expected = {
+                {TableName, "`maxim`"},
+                {ClusterName, "example"},
+                {ClusterName, "yt:saurus"},
+                {Keyword, "ANY"},
+            };
+            UNIT_ASSERT_VALUES_EQUAL(Complete(engine, "USE yt:saurus; SELECT * FROM "), expected);
+        }
+        {
+            TVector<TCandidate> expected = {
+                {TableName, "`people`"},
+                {FolderName, "`yql/`"},
+            };
+            UNIT_ASSERT_VALUES_EQUAL(Complete(engine, "USE yt:saurus; SELECT * FROM example."), expected);
+        }
+        {
+            TVector<TCandidate> expected = {
+                {TableName, "`maxim`"},
+                {ClusterName, "example"},
+                {ClusterName, "yt:saurus"},
+                {Keyword, "ANY"},
+            };
+            UNIT_ASSERT_VALUES_EQUAL(Complete(engine, "USE example; USE yt:saurus; SELECT * FROM "), expected);
+        }
+        {
+            TVector<TCandidate> expected = {
+                {TableName, "`maxim`"},
+                {ClusterName, "example"},
+                {ClusterName, "yt:saurus"},
+                {Keyword, "ANY"},
+            };
+            UNIT_ASSERT_VALUES_EQUAL(Complete(engine, R"(
+                USE example; 
+                DEFINE ACTION $hello() AS 
+                    USE yt:saurus;
+                    SELECT * FROM #;
+                END DEFINE;
+            )"), expected);
+        }
+        {
+            TVector<TCandidate> expected = {
+                {TableName, "`people`"},
+                {FolderName, "`yql/`"},
+                {ClusterName, "example"},
+                {ClusterName, "yt:saurus"},
+                {Keyword, "ANY"},
+            };
+            UNIT_ASSERT_VALUES_EQUAL(Complete(engine, R"(
+                USE example;
+
+                DEFINE ACTION $action() AS
+                    USE yt:saurus;
+                    SELECT * FROM test;
+                END DEFINE;
+
+                SELECT * FROM #
+            )"), expected);
+        }
+    }
+
     Y_UNIT_TEST(SelectWhere) {
         TVector<TCandidate> expected = {
             {Keyword, "BITCAST("},