Added ALTER TABLE support to constraints (ADD CONSTRAINT, DROP CONSTRAINT)

dbms/src/Databases/DatabaseDictionary.cpp

@@ -131,6 +131,7 @@ void DatabaseDictionary::alterTable(
     const String &,
     const ColumnsDescription &,
     const IndicesDescription &,
+    const ConstraintsDescription &,
     const ASTModifier &)
 {
     throw Exception("DatabaseDictionary: alterTable() is not supported", ErrorCodes::NOT_IMPLEMENTED);

dbms/src/Databases/DatabaseDictionary.h

@@ -72,6 +72,7 @@ public:
         const String & name,
         const ColumnsDescription & columns,
         const IndicesDescription & indices,
+        const ConstraintsDescription & constraints,
         const ASTModifier & engine_modifier) override;
 
     time_t getTableMetadataModificationTime(

dbms/src/Databases/DatabaseMemory.cpp

@@ -54,6 +54,7 @@ void DatabaseMemory::alterTable(
     const String &,
     const ColumnsDescription &,
     const IndicesDescription &,
+    const ConstraintsDescription &,
     const ASTModifier &)
 {
     throw Exception("DatabaseMemory: alterTable() is not supported", ErrorCodes::NOT_IMPLEMENTED);

dbms/src/Databases/DatabaseMemory.h

@@ -49,6 +49,7 @@ public:
         const String & name,
         const ColumnsDescription & columns,
         const IndicesDescription & indices,
+        const ConstraintsDescription & constraints,
         const ASTModifier & engine_modifier) override;
 
     time_t getTableMetadataModificationTime(

dbms/src/Databases/DatabaseOrdinary.cpp

@@ -516,6 +516,7 @@ void DatabaseOrdinary::alterTable(
     const String & table_name,
     const ColumnsDescription & columns,
     const IndicesDescription & indices,
+    const ConstraintsDescription & constraints,
     const ASTModifier & storage_modifier)
 {
     /// Read the definition of the table and replace the necessary parts with new ones.
@@ -538,6 +539,7 @@ void DatabaseOrdinary::alterTable(
 
     ASTPtr new_columns = InterpreterCreateQuery::formatColumns(columns);
     ASTPtr new_indices = InterpreterCreateQuery::formatIndices(indices);
+    ASTPtr new_constraints = InterpreterCreateQuery::formatConstraints(constraints);
 
     ast_create_query.columns_list->replace(ast_create_query.columns_list->columns, new_columns);
 
@@ -546,6 +548,11 @@ void DatabaseOrdinary::alterTable(
     else
         ast_create_query.columns_list->set(ast_create_query.columns_list->indices, new_indices);
 
+    if (ast_create_query.columns_list->constraints)
+        ast_create_query.columns_list->replace(ast_create_query.columns_list->constraints, new_constraints);
+    else
+        ast_create_query.columns_list->set(ast_create_query.columns_list->constraints, new_constraints);
+
     if (storage_modifier)
         storage_modifier(*ast_create_query.storage);
 

dbms/src/Databases/DatabaseOrdinary.h

@@ -43,6 +43,7 @@ public:
         const String & name,
         const ColumnsDescription & columns,
         const IndicesDescription & indices,
+        const ConstraintsDescription & constraints,
         const ASTModifier & engine_modifier) override;
 
     time_t getTableMetadataModificationTime(

dbms/src/Databases/IDatabase.h

@@ -6,6 +6,7 @@
 #include <Parsers/IAST_fwd.h>
 #include <Storages/ColumnsDescription.h>
 #include <Storages/IndicesDescription.h>
+#include <Storages/ConstraintsDescription.h>
 #include <Storages/IStorage_fwd.h>
 #include <Poco/File.h>
 #include <Common/ThreadPool.h>
@@ -114,6 +115,7 @@ public:
         const String & name,
         const ColumnsDescription & columns,
         const IndicesDescription & indices,
+        const ConstraintsDescription & constraints,
         const ASTModifier & engine_modifier) = 0;
 
     /// Returns time of table's metadata change, 0 if there is no corresponding metadata file.

dbms/src/Parsers/ASTAlterQuery.cpp

@@ -105,6 +105,17 @@ void ASTAlterCommand::formatImpl(
                       << "DROP INDEX " << (if_exists ? "IF EXISTS " : "") << (settings.hilite ? hilite_none : "");
         index->formatImpl(settings, state, frame);
     }
+    else if (type == ASTAlterCommand::ADD_CONSTRAINT)
+    {
+        settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "ADD CONSTRAINT" << (if_not_exists ? "IF NOT EXISTS " : "") << (settings.hilite ? hilite_none : "");
+        constraint_decl->formatImpl(settings, state, frame);
+    }
+    else if (type == ASTAlterCommand::DROP_CONSTRAINT)
+    {
+        settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str
+                      << "DROP CONSTRAINT " << (if_exists ? "IF EXISTS " : "") << (settings.hilite ? hilite_none : "");
+        constraint->formatImpl(settings, state, frame);
+    }
     else if (type == ASTAlterCommand::DROP_PARTITION)
     {
         settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << (detach ? "DETACH" : "DROP") << " PARTITION "

dbms/src/Parsers/ASTAlterQuery.h

@@ -32,6 +32,9 @@ public:
         ADD_INDEX,
         DROP_INDEX,
 
+        ADD_CONSTRAINT,
+        DROP_CONSTRAINT,
+
         DROP_PARTITION,
         ATTACH_PARTITION,
         REPLACE_PARTITION,
@@ -71,6 +74,14 @@ public:
      */
     ASTPtr index;
 
+    /** The ADD CONSTRAINT query stores the ConstraintDeclaration there.
+    */
+    ASTPtr constraint_decl;
+
+    /** The DROP CONSTRAINT query stores the name for deletion.
+    */
+    ASTPtr constraint;
+
     /** Used in DROP PARTITION and ATTACH PARTITION FROM queries.
      *  The value or ID of the partition is stored here.
      */

dbms/src/Parsers/ParserAlterQuery.cpp

@@ -32,6 +32,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
     ParserKeyword s_add_index("ADD INDEX");
     ParserKeyword s_drop_index("DROP INDEX");
 
+    ParserKeyword s_add_constraint("ADD CONSTRAINT");
+    ParserKeyword s_drop_constraint("DROP CONSTRAINT");
+
     ParserKeyword s_attach_partition("ATTACH PARTITION");
     ParserKeyword s_detach_partition("DETACH PARTITION");
     ParserKeyword s_drop_partition("DROP PARTITION");
@@ -57,6 +60,7 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
     ParserStringLiteral parser_string_literal;
     ParserCompoundColumnDeclaration parser_col_decl;
     ParserIndexDeclaration parser_idx_decl;
+    ParserConstraintDeclaration parser_constraint_decl;
     ParserCompoundColumnDeclaration parser_modify_col_decl(false);
     ParserPartition parser_partition;
     ParserExpression parser_exp_elem;
@@ -125,6 +129,27 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
         command->type = ASTAlterCommand::DROP_INDEX;
         command->detach = false;
     }
+    else if (s_add_constraint.ignore(pos, expected))
+    {
+        if (s_if_not_exists.ignore(pos, expected))
+            command->if_not_exists = true;
+
+        if (!parser_constraint_decl.parse(pos, command->constraint_decl, expected))
+            return false;
+
+        command->type = ASTAlterCommand::ADD_CONSTRAINT;
+    }
+    else if (s_drop_constraint.ignore(pos, expected))
+    {
+        if (s_if_exists.ignore(pos, expected))
+            command->if_exists = true;
+
+        if (!parser_name.parse(pos, command->constraint, expected))
+            return false;
+
+        command->type = ASTAlterCommand::DROP_CONSTRAINT;
+        command->detach = false;
+    }
     else if (s_clear_column.ignore(pos, expected))
     {
         if (s_if_exists.ignore(pos, expected))

dbms/src/Storages/AlterCommands.cpp

@@ -9,6 +9,7 @@
 #include <Interpreters/ExpressionActions.h>
 #include <Parsers/ASTIdentifier.h>
 #include <Parsers/ASTIndexDeclaration.h>
+#include <Parsers/ASTConstraintDeclaration.h>
 #include <Parsers/ASTExpressionList.h>
 #include <Parsers/ASTLiteral.h>
 #include <Parsers/ASTFunction.h>
@@ -165,6 +166,32 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
 
         return command;
     }
+    else if (command_ast->type == ASTAlterCommand::ADD_CONSTRAINT)
+    {
+        AlterCommand command;
+        command.constraint_decl = command_ast->constraint_decl;
+        command.type = AlterCommand::ADD_CONSTRAINT;
+
+        const auto & ast_constraint_decl = command_ast->constraint_decl->as<ASTConstraintDeclaration &>();
+
+        command.constraint_name = ast_constraint_decl.name;
+
+        command.if_not_exists = command_ast->if_not_exists;
+
+        return command;
+    }
+    else if (command_ast->type == ASTAlterCommand::DROP_CONSTRAINT)
+    {
+        if (command_ast->clear_column)
+            throw Exception("\"ALTER TABLE table CLEAR COLUMN column\" queries are not supported yet. Use \"CLEAR COLUMN column IN PARTITION\".", ErrorCodes::NOT_IMPLEMENTED);
+
+        AlterCommand command;
+        command.type = AlterCommand::DROP_CONSTRAINT;
+        command.constraint_name = command_ast->constraint->as<ASTIdentifier &>().name;
+        command.if_exists = command_ast->if_exists;
+
+        return command;
+    }
     else if (command_ast->type == ASTAlterCommand::MODIFY_TTL)
     {
         AlterCommand command;
@@ -178,6 +205,7 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
 
 
 void AlterCommand::apply(ColumnsDescription & columns_description, IndicesDescription & indices_description,
+                         ConstraintsDescription & constraints_description,
                          ASTPtr & order_by_ast, ASTPtr & primary_key_ast, ASTPtr & ttl_table_ast) const
 {
     if (type == ADD_COLUMN)
@@ -298,6 +326,44 @@ void AlterCommand::apply(ColumnsDescription & columns_description, IndicesDescri
 
         indices_description.indices.erase(erase_it);
     }
+    else if (type == ADD_CONSTRAINT)
+    {
+        if (std::any_of(
+                constraints_description.constraints.cbegin(),
+                constraints_description.constraints.cend(),
+                [this](const ASTPtr & constraint_ast)
+                {
+                    return constraint_ast->as<ASTConstraintDeclaration &>().name == constraint_name;
+                }))
+        {
+            if (if_not_exists)
+                return;
+            throw Exception("Cannot add constraint " + constraint_name + ": constraint with this name already exists",
+                        ErrorCodes::ILLEGAL_COLUMN);
+        }
+
+        auto insert_it = constraints_description.constraints.end();
+
+        constraints_description.constraints.emplace(insert_it, std::dynamic_pointer_cast<ASTConstraintDeclaration>(constraint_decl));
+    }
+    else if (type == DROP_CONSTRAINT)
+    {
+        auto erase_it = std::find_if(
+                constraints_description.constraints.begin(),
+                constraints_description.constraints.end(),
+                [this](const ASTPtr & constraint_ast)
+                {
+                    return constraint_ast->as<ASTConstraintDeclaration &>().name == constraint_name;
+                });
+
+        if (erase_it == constraints_description.constraints.end()) {
+            if (if_exists)
+                return;
+            throw Exception("Wrong constraint name. Cannot find constraint `" + constraint_name + "` to drop.",
+                    ErrorCodes::LOGICAL_ERROR);
+        }
+        constraints_description.constraints.erase(erase_it);
+    }
     else if (type == MODIFY_TTL)
     {
         ttl_table_ast = ttl;
@@ -317,20 +383,23 @@ bool AlterCommand::isMutable() const
 }
 
 void AlterCommands::apply(ColumnsDescription & columns_description, IndicesDescription & indices_description,
+                          ConstraintsDescription & constraints_description,
                           ASTPtr & order_by_ast, ASTPtr & primary_key_ast, ASTPtr & ttl_table_ast) const
 {
     auto new_columns_description = columns_description;
     auto new_indices_description = indices_description;
+    auto new_constraints_description = constraints_description;
     auto new_order_by_ast = order_by_ast;
     auto new_primary_key_ast = primary_key_ast;
     auto new_ttl_table_ast = ttl_table_ast;
 
     for (const AlterCommand & command : *this)
         if (!command.ignore)
-            command.apply(new_columns_description, new_indices_description, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
+            command.apply(new_columns_description, new_indices_description, new_constraints_description, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
 
     columns_description = std::move(new_columns_description);
     indices_description = std::move(new_indices_description);
+    constraints_description = std::move(new_constraints_description);
     order_by_ast = std::move(new_order_by_ast);
     primary_key_ast = std::move(new_primary_key_ast);
     ttl_table_ast = std::move(new_ttl_table_ast);
@@ -518,10 +587,11 @@ void AlterCommands::apply(ColumnsDescription & columns_description) const
 {
     auto out_columns_description = columns_description;
     IndicesDescription indices_description;
+    ConstraintsDescription constraints_description;
     ASTPtr out_order_by;
     ASTPtr out_primary_key;
     ASTPtr out_ttl_table;
-    apply(out_columns_description, indices_description, out_order_by, out_primary_key, out_ttl_table);
+    apply(out_columns_description, indices_description, constraints_description, out_order_by, out_primary_key, out_ttl_table);
 
     if (out_order_by)
         throw Exception("Storage doesn't support modifying ORDER BY expression", ErrorCodes::NOT_IMPLEMENTED);
@@ -529,6 +599,8 @@ void AlterCommands::apply(ColumnsDescription & columns_description) const
         throw Exception("Storage doesn't support modifying PRIMARY KEY expression", ErrorCodes::NOT_IMPLEMENTED);
     if (!indices_description.indices.empty())
         throw Exception("Storage doesn't support modifying indices", ErrorCodes::NOT_IMPLEMENTED);
+    if (!constraints_description.constraints.empty())
+        throw Exception("Storage doesn't support modifying constraints", ErrorCodes::NOT_IMPLEMENTED);
     if (out_ttl_table)
         throw Exception("Storage doesn't support modifying TTL expression", ErrorCodes::NOT_IMPLEMENTED);
 

dbms/src/Storages/AlterCommands.h

@@ -5,6 +5,7 @@
 #include <Storages/ColumnsDescription.h>
 #include <Storages/IStorage_fwd.h>
 #include <Storages/IndicesDescription.h>
+#include <Storages/ConstraintsDescription.h>
 
 
 namespace DB
@@ -25,6 +26,8 @@ struct AlterCommand
         MODIFY_ORDER_BY,
         ADD_INDEX,
         DROP_INDEX,
+        ADD_CONSTRAINT,
+        DROP_CONSTRAINT,
         MODIFY_TTL,
         UKNOWN_TYPE,
     };
@@ -62,6 +65,12 @@ struct AlterCommand
     /// For ADD/DROP INDEX
     String index_name;
 
+    // For ADD CONSTRAINT
+    ASTPtr constraint_decl;
+
+    // For ADD/DROP CONSTRAINT
+    String constraint_name;
+
     /// For MODIFY TTL
     ASTPtr ttl;
 
@@ -84,6 +93,7 @@ struct AlterCommand
     static std::optional<AlterCommand> parse(const ASTAlterCommand * command);
 
     void apply(ColumnsDescription & columns_description, IndicesDescription & indices_description,
+               ConstraintsDescription & constraints_description,
                ASTPtr & order_by_ast, ASTPtr & primary_key_ast, ASTPtr & ttl_table_ast) const;
 
     /// Checks that not only metadata touched by that command
@@ -95,8 +105,9 @@ class Context;
 class AlterCommands : public std::vector<AlterCommand>
 {
 public:
-    void apply(ColumnsDescription & columns_description, IndicesDescription & indices_description, ASTPtr & order_by_ast,
+    void apply(ColumnsDescription & columns_description, IndicesDescription & indices_description,
-            ASTPtr & primary_key_ast, ASTPtr & ttl_table_ast) const;
+               ConstraintsDescription & constraints_description,
+               ASTPtr & order_by_ast, ASTPtr & primary_key_ast, ASTPtr & ttl_table_ast) const;
 
     /// For storages that don't support MODIFY_ORDER_BY.
     void apply(ColumnsDescription & columns_description) const;

dbms/src/Storages/IStorage.cpp

@@ -346,8 +346,9 @@ void IStorage::alter(
     lockStructureExclusively(table_lock_holder, context.getCurrentQueryId());
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     params.apply(new_columns);
-    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, {});
+    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, new_constraints, {});
     setColumns(std::move(new_columns));
 }
 

dbms/src/Storages/MergeTree/MergeTreeData.cpp

@@ -121,7 +121,7 @@ MergeTreeData::MergeTreeData(
     data_parts_by_info(data_parts_indexes.get<TagByInfo>()),
     data_parts_by_state_and_info(data_parts_indexes.get<TagByStateAndInfo>())
 {
-    setPrimaryKeyIndicesAndColumns(order_by_ast_, primary_key_ast_, columns_, indices_);
+    setPrimaryKeyIndicesAndColumns(order_by_ast_, primary_key_ast_, columns_, indices_, constraints_);
     setConstraints(constraints_);
 
     /// NOTE: using the same columns list as is read when performing actual merges.
@@ -255,7 +255,8 @@ static void checkKeyExpression(const ExpressionActions & expr, const Block & sam
 
 void MergeTreeData::setPrimaryKeyIndicesAndColumns(
     const ASTPtr & new_order_by_ast, const ASTPtr & new_primary_key_ast,
-    const ColumnsDescription & new_columns, const IndicesDescription & indices_description, bool only_check)
+    const ColumnsDescription & new_columns, const IndicesDescription & indices_description,
+    const ConstraintsDescription & constraints_description, bool only_check)
 {
     if (!new_order_by_ast)
         throw Exception("ORDER BY cannot be empty", ErrorCodes::BAD_ARGUMENTS);
@@ -425,6 +426,8 @@ void MergeTreeData::setPrimaryKeyIndicesAndColumns(
         setIndices(indices_description);
         skip_indices = std::move(new_indices);
 
+        setConstraints(constraints_description);
+
         primary_key_and_skip_indices_expr = new_indices_with_primary_key_expr;
         sorting_key_and_skip_indices_expr = new_indices_with_sorting_key_expr;
     }
@@ -1180,11 +1183,11 @@ void MergeTreeData::checkAlter(const AlterCommands & commands, const Context & c
     /// Check that needed transformations can be applied to the list of columns without considering type conversions.
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     ASTPtr new_order_by_ast = order_by_ast;
     ASTPtr new_primary_key_ast = primary_key_ast;
     ASTPtr new_ttl_table_ast = ttl_table_ast;
-    commands.apply(new_columns, new_indices, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
+    commands.apply(new_columns, new_indices, new_constraints, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
-
     if (getIndices().empty() && !new_indices.empty() &&
             !context.getSettingsRef().allow_experimental_data_skipping_indices)
         throw Exception("You must set the setting `allow_experimental_data_skipping_indices` to 1 " \
@@ -1267,7 +1270,7 @@ void MergeTreeData::checkAlter(const AlterCommands & commands, const Context & c
     }
 
     setPrimaryKeyIndicesAndColumns(new_order_by_ast, new_primary_key_ast,
-            new_columns, new_indices, /* only_check = */ true);
+            new_columns, new_indices, new_constraints, /* only_check = */ true);
 
     setTTLExpressions(new_columns.getColumnTTLs(), new_ttl_table_ast, /* only_check = */ true);
 

dbms/src/Storages/MergeTree/MergeTreeData.h

@@ -778,7 +778,8 @@ protected:
 
     void setPrimaryKeyIndicesAndColumns(const ASTPtr & new_order_by_ast, const ASTPtr & new_primary_key_ast,
                                         const ColumnsDescription & new_columns,
-                                        const IndicesDescription & indices_description, bool only_check = false);
+                                        const IndicesDescription & indices_description,
+                                        const ConstraintsDescription & constraints_description, bool only_check = false);
 
     void initPartitionKey();
 

dbms/src/Storages/MergeTree/ReplicatedMergeTreeTableMetadata.cpp

@@ -46,6 +46,7 @@ ReplicatedMergeTreeTableMetadata::ReplicatedMergeTreeTableMetadata(const MergeTr
         partition_key = formattedAST(MergeTreeData::extractKeyExpressionList(data.partition_by_ast));
 
     skip_indices = data.getIndices().toString();
+    constraints = data.getConstraints().toString();
     index_granularity_bytes = data.index_granularity_info.index_granularity_bytes;
     ttl_table = formattedAST(data.ttl_table_ast);
 }
@@ -229,6 +230,21 @@ ReplicatedMergeTreeTableMetadata::checkAndFindDiff(const ReplicatedMergeTreeTabl
                     ErrorCodes::METADATA_MISMATCH);
     }
 
+    if (constraints != from_zk.constraints)
+    {
+        if (allow_alter)
+        {
+            diff.constraints_changed = true;
+            diff.new_constraints = from_zk.constraints;
+        }
+        else
+            throw Exception(
+                    "Existing table metadata in ZooKeeper differs in constraints."
+                    " Stored in ZooKeeper: " + from_zk.constraints +
+                    ", local: " + constraints,
+                    ErrorCodes::METADATA_MISMATCH);
+    }
+
     if (index_granularity_bytes != from_zk.index_granularity_bytes)
         throw Exception("Existing table metadata in ZooKeeper differs in index granularity bytes."
             " Stored in ZooKeeper: " + DB::toString(from_zk.index_granularity_bytes) +

dbms/src/Storages/MergeTree/ReplicatedMergeTreeTableMetadata.h

@@ -26,6 +26,7 @@ struct ReplicatedMergeTreeTableMetadata
     String partition_key;
     String sorting_key;
     String skip_indices;
+    String constraints;
     UInt64 index_granularity_bytes;
     String ttl_table;
 
@@ -46,10 +47,13 @@ struct ReplicatedMergeTreeTableMetadata
         bool skip_indices_changed = false;
         String new_skip_indices;
 
+        bool constraints_changed = false;
+        String new_constraints;
+
         bool ttl_table_changed = false;
         String new_ttl_table;
 
-        bool empty() const { return !sorting_key_changed && !skip_indices_changed; }
+        bool empty() const { return !sorting_key_changed && !skip_indices_changed && !constraints_changed; }
     };
 
     Diff checkAndFindDiff(const ReplicatedMergeTreeTableMetadata & from_zk, bool allow_alter) const;

dbms/src/Storages/StorageBuffer.cpp

@@ -701,8 +701,9 @@ void StorageBuffer::alter(const AlterCommands & params, const String & database_
 
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     params.apply(new_columns);
-    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, {});
+    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, new_constraints, {});
     setColumns(std::move(new_columns));
 }
 

dbms/src/Storages/StorageDistributed.cpp

@@ -346,8 +346,9 @@ void StorageDistributed::alter(
 
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     params.apply(new_columns);
-    context.getDatabase(database_name)->alterTable(context, current_table_name, new_columns, new_indices, {});
+    context.getDatabase(database_name)->alterTable(context, current_table_name, new_columns, new_indices, new_constraints, {});
     setColumns(std::move(new_columns));
 }
 

dbms/src/Storages/StorageMerge.cpp

@@ -417,8 +417,9 @@ void StorageMerge::alter(
 
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     params.apply(new_columns);
-    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, {});
+    context.getDatabase(database_name)->alterTable(context, table_name, new_columns, new_indices, new_constraints, {});
     setColumns(new_columns);
 }
 

dbms/src/Storages/StorageMergeTree.cpp

@@ -242,8 +242,9 @@ void StorageMergeTree::alter(
         lockStructureExclusively(table_lock_holder, context.getCurrentQueryId());
         auto new_columns = getColumns();
         auto new_indices = getIndices();
+        auto new_constraints = getConstraints();
         params.apply(new_columns);
-        context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, {});
+        context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, new_constraints, {});
         setColumns(std::move(new_columns));
         return;
     }
@@ -252,15 +253,14 @@ void StorageMergeTree::alter(
     auto merge_blocker = merger_mutator.actions_blocker.cancel();
 
     lockNewDataStructureExclusively(table_lock_holder, context.getCurrentQueryId());
-
     checkAlter(params, context);
-
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     ASTPtr new_order_by_ast = order_by_ast;
     ASTPtr new_primary_key_ast = primary_key_ast;
     ASTPtr new_ttl_table_ast = ttl_table_ast;
-    params.apply(new_columns, new_indices, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
+    params.apply(new_columns, new_indices, new_constraints, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
 
     auto transactions = prepareAlterTransactions(new_columns, new_indices, context);
 
@@ -279,11 +279,10 @@ void StorageMergeTree::alter(
         if (new_ttl_table_ast.get() != ttl_table_ast.get())
             storage_ast.set(storage_ast.ttl_table, new_ttl_table_ast);
     };
-
+    context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, new_constraints, storage_modifier);
-    context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, storage_modifier);
 
     /// Reinitialize primary key because primary key column types might have changed.
-    setPrimaryKeyIndicesAndColumns(new_order_by_ast, new_primary_key_ast, new_columns, new_indices);
+    setPrimaryKeyIndicesAndColumns(new_order_by_ast, new_primary_key_ast, new_columns, new_indices, new_constraints);
 
     setTTLExpressions(new_columns.getColumnTTLs(), new_ttl_table_ast);
 
@@ -834,10 +833,11 @@ void StorageMergeTree::clearColumnInPartition(const ASTPtr & partition, const Fi
 
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     ASTPtr ignored_order_by_ast;
     ASTPtr ignored_primary_key_ast;
     ASTPtr ignored_ttl_table_ast;
-    alter_command.apply(new_columns, new_indices, ignored_order_by_ast, ignored_primary_key_ast, ignored_ttl_table_ast);
+    alter_command.apply(new_columns, new_indices, new_constraints, ignored_order_by_ast, ignored_primary_key_ast, ignored_ttl_table_ast);
 
     auto columns_for_parts = new_columns.getAllPhysical();
     for (const auto & part : parts)

dbms/src/Storages/StorageNull.cpp

@@ -38,8 +38,9 @@ void StorageNull::alter(
 
     ColumnsDescription new_columns = getColumns();
     IndicesDescription new_indices = getIndices();
+    ConstraintsDescription new_constraints = getConstraints();
     params.apply(new_columns);
-    context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, {});
+    context.getDatabase(current_database_name)->alterTable(context, current_table_name, new_columns, new_indices, new_constraints, {});
     setColumns(std::move(new_columns));
 }
 

dbms/src/Storages/StorageReplicatedMergeTree.cpp

@@ -422,6 +422,7 @@ void StorageReplicatedMergeTree::setTableStructure(ColumnsDescription new_column
     ASTPtr new_primary_key_ast = primary_key_ast;
     ASTPtr new_order_by_ast = order_by_ast;
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     ASTPtr new_ttl_table_ast = ttl_table_ast;
     IDatabase::ASTModifier storage_modifier;
     if (!metadata_diff.empty())
@@ -451,6 +452,9 @@ void StorageReplicatedMergeTree::setTableStructure(ColumnsDescription new_column
         if (metadata_diff.skip_indices_changed)
             new_indices = IndicesDescription::parse(metadata_diff.new_skip_indices);
 
+        if (metadata_diff.constraints_changed)
+            new_constraints = ConstraintsDescription::parse(metadata_diff.new_constraints);
+
         if (metadata_diff.ttl_table_changed)
         {
             ParserExpression parser;
@@ -476,11 +480,11 @@ void StorageReplicatedMergeTree::setTableStructure(ColumnsDescription new_column
         };
     }
 
-    global_context.getDatabase(database_name)->alterTable(global_context, table_name, new_columns, new_indices, storage_modifier);
+    global_context.getDatabase(database_name)->alterTable(global_context, table_name, new_columns, new_indices, new_constraints, storage_modifier);
 
     /// Even if the primary/sorting keys didn't change we must reinitialize it
     /// because primary key column types might have changed.
-    setPrimaryKeyIndicesAndColumns(new_order_by_ast, new_primary_key_ast, new_columns, new_indices);
+    setPrimaryKeyIndicesAndColumns(new_order_by_ast, new_primary_key_ast, new_columns, new_indices, new_constraints);
     setTTLExpressions(new_columns.getColumnTTLs(), new_ttl_table_ast);
 }
 
@@ -1507,10 +1511,11 @@ void StorageReplicatedMergeTree::executeClearColumnInPartition(const LogEntry &
 
     auto new_columns = getColumns();
     auto new_indices = getIndices();
+    auto new_constraints = getConstraints();
     ASTPtr ignored_order_by_ast;
     ASTPtr ignored_primary_key_ast;
     ASTPtr ignored_ttl_table_ast;
-    alter_command.apply(new_columns, new_indices, ignored_order_by_ast, ignored_primary_key_ast, ignored_ttl_table_ast);
+    alter_command.apply(new_columns, new_indices, new_constraints, ignored_order_by_ast, ignored_primary_key_ast, ignored_ttl_table_ast);
 
     size_t modified_parts = 0;
     auto parts = getDataParts();
@@ -3114,10 +3119,11 @@ void StorageReplicatedMergeTree::alter(
 
         ColumnsDescription new_columns = getColumns();
         IndicesDescription new_indices = getIndices();
+        ConstraintsDescription new_constraints = getConstraints();
         ASTPtr new_order_by_ast = order_by_ast;
         ASTPtr new_primary_key_ast = primary_key_ast;
         ASTPtr new_ttl_table_ast = ttl_table_ast;
-        params.apply(new_columns, new_indices, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
+        params.apply(new_columns, new_indices, new_constraints, new_order_by_ast, new_primary_key_ast, new_ttl_table_ast);
 
         String new_columns_str = new_columns.toString();
         if (new_columns_str != getColumns().toString())

dbms/tests/queries/0_stateless/00953_constraints_operations.reference

@@ -0,0 +1,4 @@
+1	2
+ok
+1	2
+ok

dbms/tests/queries/0_stateless/00953_constraints_operations.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+EXCEPTION_SUCCESS_TEXT=ok
+
+$CLICKHOUSE_CLIENT --query="DROP TABLE IF EXISTS test_constraints;"
+
+$CLICKHOUSE_CLIENT --query="CREATE TABLE test_constraints
+(
+        a       UInt32,
+        b       UInt32,
+        CONSTRAINT b_constraint CHECK b > 0
+)
+ENGINE = MergeTree ORDER BY (a);"
+
+# This one must succeed
+$CLICKHOUSE_CLIENT --query="INSERT INTO test_constraints VALUES (1, 2);"
+$CLICKHOUSE_CLIENT --query="SELECT * FROM test_constraints;"
+
+# This one must throw and exception
+EXCEPTION_TEXT="Some constraints are not satisfied"
+$CLICKHOUSE_CLIENT --query="INSERT INTO test_constraints VALUES (1, 0);" 2>&1 \
+    | grep -q "$EXCEPTION_TEXT" && echo "$EXCEPTION_SUCCESS_TEXT" || echo "Did not thrown an exception"
+$CLICKHOUSE_CLIENT --query="SELECT * FROM test_constraints;"
+
+$CLICKHOUSE_CLIENT --query="ALTER TABLE test_constraints DROP CONSTRAINT b_constraint;"
+
+# This one must suceed now
+$CLICKHOUSE_CLIENT --query="INSERT INTO test_constraints VALUES (1, 0);"
+
+$CLICKHOUSE_CLIENT --query="ALTER TABLE test_constraints ADD CONSTRAINT b_constraint CHECK b > 10;"
+
+$CLICKHOUSE_CLIENT --query="INSERT INTO test_constraints VALUES (1, 10);" 2>&1 \
+    | grep -q "$EXCEPTION_TEXT" && echo "$EXCEPTION_SUCCESS_TEXT" || echo "Did not thrown an exception"
+
+$CLICKHOUSE_CLIENT --query="INSERT INTO test_constraints VALUES (1, 11);"
+
+$CLICKHOUSE_CLIENT --query="DROP TABLE test_constraints;"