Backport #59606 to 24.1: Fix distributed table with a constant shardi…

…ng key

src/Storages/StorageDistributed.cpp

@@ -1540,10 +1540,7 @@ ClusterPtr StorageDistributed::getOptimizedCluster(
 IColumn::Selector StorageDistributed::createSelector(const ClusterPtr cluster, const ColumnWithTypeAndName & result)
 {
     const auto & slot_to_shard = cluster->getSlotToShard();
-
     const IColumn * column = result.column.get();
-    if (const auto * col_const = typeid_cast<const ColumnConst *>(column))
-        column = &col_const->getDataColumn();
 
 // If result.type is DataTypeLowCardinality, do shard according to its dictionaryType
 #define CREATE_FOR_TYPE(TYPE)                                                                                       \

tests/queries/0_stateless/02983_const_sharding_key.reference

@@ -0,0 +1,7 @@
+1
+2
+3
+4
+5
+6
+7

tests/queries/0_stateless/02983_const_sharding_key.sql

@@ -0,0 +1,26 @@
+-- Tags: distributed, no-parallel
+
+DROP DATABASE IF EXISTS shard_0;
+DROP DATABASE IF EXISTS shard_1;
+DROP TABLE IF EXISTS t_distr;
+
+CREATE DATABASE IF NOT EXISTS shard_0;
+CREATE DATABASE IF NOT EXISTS shard_1;
+
+CREATE TABLE shard_0.t_local (a Int) ENGINE = Memory;
+CREATE TABLE shard_1.t_local (a Int) ENGINE = Memory;
+CREATE TABLE t_distr (a Int) ENGINE = Distributed(test_cluster_two_shards_different_databases, '', 't_local', 1000);
+
+SET distributed_foreground_insert=0;
+INSERT INTO t_distr VALUES (1), (2), (3);
+
+SET distributed_foreground_insert=1;
+INSERT INTO t_distr VALUES (4), (5), (6), (7);
+
+SYSTEM FLUSH DISTRIBUTED t_distr;
+
+SELECT * FROM t_distr ORDER BY a;
+
+DROP TABLE t_distr;
+DROP DATABASE shard_0;
+DROP DATABASE shard_1;