Fix KeyCondition with no common types

src/DataTypes/getLeastSupertype.cpp

@@ -530,4 +530,16 @@ DataTypePtr getLeastSupertype(const DataTypes & types)
     throw Exception(getExceptionMessagePrefix(types), ErrorCodes::NO_COMMON_TYPE);
 }
 
+DataTypePtr tryGetLeastSupertype(const DataTypes & types)
+{
+    try
+    {
+        return getLeastSupertype(types);
+    }
+    catch (...)
+    {
+        return nullptr;
+    }
+}
+
 }

src/DataTypes/getLeastSupertype.h

@@ -14,4 +14,7 @@ namespace DB
   */
 DataTypePtr getLeastSupertype(const DataTypes & types);
 
+/// Same as above but return nullptr instead of throwing exception.
+DataTypePtr tryGetLeastSupertype(const DataTypes & types);
+
 }

src/Storages/MergeTree/KeyCondition.cpp

@@ -1306,7 +1306,10 @@ bool KeyCondition::tryParseAtomFromAST(const ASTPtr & node, ContextPtr context,
                 }
                 else
                 {
-                    DataTypePtr common_type = getLeastSupertype({key_expr_type_not_null, const_type});
+                    DataTypePtr common_type = tryGetLeastSupertype({key_expr_type_not_null, const_type});
+                    if (!common_type)
+                        return false;
+
                     if (!const_type->equals(*common_type))
                     {
                         castValueToType(common_type, const_value, const_type, node);

tests/queries/0_stateless/02179_key_condition_no_common_type.reference

@@ -0,0 +1 @@
+0.9

tests/queries/0_stateless/02179_key_condition_no_common_type.sql

@@ -0,0 +1,9 @@
+drop table if exists t;
+
+create table t (c Decimal32(9)) engine MergeTree order by c;
+
+insert into t values (0.9);
+
+select * from t where c < 1.2;
+
+drop table t;