support cast in default values (#1754)

3 files changed, 117 insertions, 16 deletions

diff --git a/ydb/core/kqp/provider/yql_kikimr_datasink.cpp b/ydb/core/kqp/provider/yql_kikimr_datasink.cpp
index 9c6243f35c..ff58db6e9f 100644
--- a/ydb/core/kqp/provider/yql_kikimr_datasink.cpp
+++ b/ydb/core/kqp/provider/yql_kikimr_datasink.cpp
@@ -787,7 +787,7 @@ public:
                     auto replaceIfExists = (settings.Mode.Cast().Value() == "create_or_replace");
                     auto existringOk = (settings.Mode.Cast().Value() == "create_if_not_exists");
 
-                    return Build<TKiCreateTable>(ctx, node->Pos())
+                    auto createTable = Build<TKiCreateTable>(ctx, node->Pos())
                         .World(node->Child(0))
                         .DataSink(node->Child(1))
                         .Table().Build(key.GetTablePath())
@@ -807,8 +807,47 @@ public:
                         .ExistingOk<TCoAtom>()
                             .Value(existringOk)
                             .Build()
-                        .Done()
-                        .Ptr();
+                        .Done();
+
+                    bool exprEvalNeeded = false;
+
+                    for(auto item: createTable.Cast<TKiCreateTable>().Columns()) {
+                        auto columnTuple = item.Cast<TExprList>();
+                        if (columnTuple.Size() > 2) {
+                            const auto& columnConstraints = columnTuple.Item(2).Cast<TCoNameValueTuple>();
+                            for(const auto& constraint: columnConstraints.Value().Cast<TCoNameValueTupleList>()) {
+                                if (constraint.Name().Value() != "default")
+                                    continue;
+
+                                YQL_ENSURE(constraint.Value().IsValid());
+                                bool shouldEvaluate = (
+                                    constraint.Value().Cast().Ptr()->IsCallable() &&
+                                    (constraint.Value().Cast().Ptr()->Content() == "PgCast") &&
+                                    (constraint.Value().Cast().Ptr()->ChildrenSize() >= 1) &&
+                                    (constraint.Value().Cast().Ptr()->Child(0)->IsCallable()) &&
+                                    (constraint.Value().Cast().Ptr()->Child(0)->Content() == "PgConst")
+                                );
+
+                                if (shouldEvaluate) {
+                                    auto evaluatedExpr = ctx.Builder(constraint.Value().Cast().Ptr()->Pos())
+                                        .Callable("EvaluateExpr")
+                                        .Add(0, constraint.Value().Cast().Ptr())
+                                        .Seal()
+                                        .Build();
+
+                                    constraint.Ptr()->ChildRef(TCoNameValueTuple::idx_Value) = evaluatedExpr;
+                                    exprEvalNeeded = true;
+                                }
+                            }
+                        }
+                    }
+
+                    if (exprEvalNeeded) {
+                        ctx.Step.Repeat(TExprStep::ExprEval);
+                    }
+
+                    return createTable.Ptr();
+
                 } else if (mode == "alter") {
                     for (auto setting : settings.Other) {
                         if (setting.Name().Value() == "intent") {
diff --git a/ydb/core/kqp/provider/yql_kikimr_type_ann.cpp b/ydb/core/kqp/provider/yql_kikimr_type_ann.cpp
index e2bbc5db7c..9db48a960e 100644
--- a/ydb/core/kqp/provider/yql_kikimr_type_ann.cpp
+++ b/ydb/core/kqp/provider/yql_kikimr_type_ann.cpp
@@ -808,7 +808,13 @@ virtual TStatus HandleCreateTable(TKiCreateTable create, TExprContext& ctx) over
 
                         columnMeta.SetDefaultFromLiteral();
 
-                        if (auto pgConst = constraint.Value().Maybe<TCoPgConst>()) {
+                        YQL_ENSURE(constraint.Value().IsValid());
+                        const auto& constrValue = constraint.Value().Cast();
+                        bool isPgNull = constrValue.Ptr()->IsCallable() &&
+                            constrValue.Ptr()->Content() == "PgCast" && constrValue.Ptr()->ChildrenSize() >= 1 &&
+                            constrValue.Ptr()->Child(0)->IsCallable() && constrValue.Ptr()->Child(0)->Content() == "Null";
+
+                        if (constrValue.Maybe<TCoPgConst>() || isPgNull) {
                             auto actualPgType = actualType->Cast<TPgExprType>();
                             YQL_ENSURE(actualPgType);
 
@@ -819,25 +825,38 @@ virtual TStatus HandleCreateTable(TKiCreateTable create, TExprContext& ctx) over
                                 return TStatus::Error;
                             }
 
-                            TString content = TString(pgConst.Cast().Value().Value());
-                            auto parseResult = NKikimr::NPg::PgNativeBinaryFromNativeText(content, typeDesc);
-                            if (parseResult.Error) {
-                                ctx.AddError(TIssue(ctx.GetPosition(constraint.Pos()),
-                                    TStringBuilder() << "Failed to parse default expr for typename " << actualPgType->GetName()
-                                    << ", error reason: " << *parseResult.Error));
-                                return TStatus::Error;
+                            if (isPgNull) {
+                                if (columnMeta.NotNull) {
+                                    ctx.AddError(TIssue(ctx.GetPosition(constraint.Pos()), TStringBuilder() << "Default expr " << columnName
+                                        << " is nullable or optional, but column has not null constraint. "));
+                                    return TStatus::Error;
+                                }
+
+                                columnMeta.DefaultFromLiteral.mutable_value()->set_null_flag_value(NProtoBuf::NULL_VALUE);
+
+                            } else {
+                                YQL_ENSURE(constrValue.Maybe<TCoPgConst>());
+                                auto pgConst = constrValue.Cast<TCoPgConst>();
+                                TString content = TString(pgConst.Value().Value());
+                                auto parseResult = NKikimr::NPg::PgNativeBinaryFromNativeText(content, typeDesc);
+                                if (parseResult.Error) {
+                                    ctx.AddError(TIssue(ctx.GetPosition(constraint.Pos()),
+                                        TStringBuilder() << "Failed to parse default expr for typename " << actualPgType->GetName()
+                                        << ", error reason: " << *parseResult.Error));
+                                    return TStatus::Error;
+                                }
+
+                                columnMeta.DefaultFromLiteral.mutable_value()->set_bytes_value(parseResult.Str);
                             }
 
-                            columnMeta.DefaultFromLiteral.mutable_value()->set_bytes_value(parseResult.Str);
                             auto* pg = columnMeta.DefaultFromLiteral.mutable_type()->mutable_pg_type();
-
                             pg->set_type_name(NKikimr::NPg::PgTypeNameFromTypeDesc(typeDesc));
                             pg->set_oid(NKikimr::NPg::PgTypeIdFromTypeDesc(typeDesc));
-                        } else if (auto literal = constraint.Value().Maybe<TCoDataCtor>()) {
-                            FillLiteralProto(constraint.Value().Cast<TCoDataCtor>(), columnMeta.DefaultFromLiteral);
+                        } else if (auto literal = constrValue.Maybe<TCoDataCtor>()) {
+                            FillLiteralProto(literal.Cast(), columnMeta.DefaultFromLiteral);
                         } else {
                             ctx.AddError(TIssue(ctx.GetPosition(constraint.Pos()),
-                                TStringBuilder() << "Unsupported type of default value " << constraint.Value().Cast().Ptr()->Content()));
+                                TStringBuilder() << "Unsupported type of default value"));
                             return TStatus::Error;
                         }
 
diff --git a/ydb/core/kqp/ut/pg/kqp_pg_ut.cpp b/ydb/core/kqp/ut/pg/kqp_pg_ut.cpp
index 6eaabcfc43..1066a40bc5 100644
--- a/ydb/core/kqp/ut/pg/kqp_pg_ut.cpp
+++ b/ydb/core/kqp/ut/pg/kqp_pg_ut.cpp
@@ -3401,6 +3401,49 @@ Y_UNIT_TEST_SUITE(KqpPg) {
         }
     }
 
+    Y_UNIT_TEST(InsertValuesFromTableWithDefaultAndCast) {
+        NKikimrConfig::TAppConfig appConfig;
+        appConfig.MutableTableServiceConfig()->SetEnablePreparedDdl(true);
+        auto setting = NKikimrKqp::TKqpSetting();
+        auto serverSettings = TKikimrSettings()
+            .SetAppConfig(appConfig)
+            .SetKqpSettings({setting});
+        TKikimrRunner kikimr(serverSettings.SetWithSampleTables(false));
+        auto db = kikimr.GetQueryClient();
+        auto settings = NYdb::NQuery::TExecuteQuerySettings().Syntax(NYdb::NQuery::ESyntax::Pg);
+        {
+            auto result = db.ExecuteQuery(R"(
+                CREATE TABLE t (
+                    a INT,
+                    b int DEFAULT 5::int4,
+                    c int DEFAULT '7'::int4,
+                    d varchar(20) DEFAULT 'foo'::varchar(2),
+                    e int DEFAULT NULL,
+                    f bit varying(5) DEFAULT '1001',
+                    PRIMARY KEY(a)
+                );
+            )", NYdb::NQuery::TTxControl::NoTx(), settings).ExtractValueSync();
+            UNIT_ASSERT_C(result.IsSuccess(), result.GetIssues().ToString());
+        }
+        {
+            auto result = db.ExecuteQuery(R"(
+                INSERT INTO t VALUES(1);
+            )", NYdb::NQuery::TTxControl::BeginTx().CommitTx(), settings).ExtractValueSync();
+            UNIT_ASSERT_VALUES_EQUAL_C(result.GetStatus(), EStatus::SUCCESS, result.GetIssues().ToString());
+        }
+        {
+            auto result = db.ExecuteQuery(R"(
+                SELECT * FROM t;
+            )", NYdb::NQuery::TTxControl::BeginTx().CommitTx(), settings).ExtractValueSync();
+            UNIT_ASSERT_VALUES_EQUAL_C(result.GetStatus(), EStatus::SUCCESS, result.GetIssues().ToString());
+
+            UNIT_ASSERT_C(!result.GetResultSets().empty(), "results are empty");
+            CompareYson(R"(
+                [["1";"5";"7";"fo";#;"1001"]]
+            )", FormatResultSetYson(result.GetResultSet(0)));
+        }
+    }
+
     Y_UNIT_TEST(InsertValuesFromTableWithDefaultBool) {
         NKikimrConfig::TAppConfig appConfig;
         appConfig.MutableTableServiceConfig()->SetEnablePreparedDdl(true);