[Enhancement] (nereids)implement showTriggersCommand in nereids

fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4

@@ -216,6 +216,7 @@ supportedShowStatement
     | SHOW CREATE MATERIALIZED VIEW mvName=identifier
         ON tableName=multipartIdentifier                                            #showCreateMaterializedView   
     | SHOW BACKENDS                                                                 #showBackends
+    | SHOW FULL? TRIGGERS ((FROM | IN) database=multipartIdentifier)? wildWhere?    #showTriggers    
     | SHOW FRONTENDS name=identifier?                                               #showFrontends 
     | SHOW TABLE tableId=INTEGER_VALUE                                              #showTableId
     | SHOW WHITELIST                                                                #showWhitelist
@@ -261,7 +262,6 @@ unsupportedShowStatement
     | SHOW FULL? VIEWS ((FROM | IN) database=multipartIdentifier)? wildWhere?       #showViews
     | SHOW FULL? PROCESSLIST                                                        #showProcessList
     | SHOW (GLOBAL | SESSION | LOCAL)? STATUS wildWhere?                            #showStatus
-    | SHOW FULL? TRIGGERS ((FROM | IN) database=multipartIdentifier)? wildWhere?    #showTriggers
     | SHOW EVENTS ((FROM | IN) database=multipartIdentifier)? wildWhere?            #showEvents
     | SHOW BRIEF? CREATE TABLE name=multipartIdentifier                             #showCreateTable
     | SHOW CREATE VIEW name=multipartIdentifier                                     #showCreateView

fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java

@@ -216,6 +216,7 @@
 import org.apache.doris.nereids.DorisParser.ShowSqlBlockRuleContext;
 import org.apache.doris.nereids.DorisParser.ShowStorageEnginesContext;
 import org.apache.doris.nereids.DorisParser.ShowTableIdContext;
+import org.apache.doris.nereids.DorisParser.ShowTriggersContext;
 import org.apache.doris.nereids.DorisParser.ShowVariablesContext;
 import org.apache.doris.nereids.DorisParser.ShowViewContext;
 import org.apache.doris.nereids.DorisParser.ShowWhitelistContext;
@@ -466,6 +467,7 @@
 import org.apache.doris.nereids.trees.plans.commands.ShowSqlBlockRuleCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowStorageEnginesCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowTableIdCommand;
+import org.apache.doris.nereids.trees.plans.commands.ShowTriggersCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowVariablesCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowViewCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowWhiteListCommand;
@@ -4142,6 +4144,7 @@ public LogicalPlan visitShowBackends(ShowBackendsContext ctx) {
         return new ShowBackendsCommand();
     }
 
+    @Override
     public LogicalPlan visitShowPlugins(ShowPluginsContext ctx) {
         return new ShowPluginsCommand();
     }
@@ -4155,6 +4158,11 @@ public LogicalPlan visitShowSqlBlockRule(ShowSqlBlockRuleContext ctx) {
         return new ShowSqlBlockRuleCommand(ruleName);
     }
 
+    @Override
+    public LogicalPlan visitShowTriggers(ShowTriggersContext ctx) {
+        return new ShowTriggersCommand();
+    }
+
     @Override
     public LogicalPlan visitShowRepositories(ShowRepositoriesContext ctx) {
         return new ShowRepositoriesCommand();

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/PlanType.java

@@ -192,6 +192,7 @@ public enum PlanType {
     SHOW_ROLE_COMMAND,
     SHOW_STORAGE_ENGINES_COMMAND,
     SHOW_TABLE_ID_COMMAND,
+    SHOW_TRIGGERS_COMMAND,
     SHOW_VARIABLES_COMMAND,
     SHOW_AUTHORS_COMMAND,
     SHOW_VIEW_COMMAND,

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/commands/ShowTriggersCommand.java

@@ -0,0 +1,66 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package org.apache.doris.nereids.trees.plans.commands;
+
+import org.apache.doris.catalog.Column;
+import org.apache.doris.catalog.ScalarType;
+import org.apache.doris.nereids.trees.plans.PlanType;
+import org.apache.doris.nereids.trees.plans.visitor.PlanVisitor;
+import org.apache.doris.qe.ConnectContext;
+import org.apache.doris.qe.ShowResultSet;
+import org.apache.doris.qe.ShowResultSetMetaData;
+import org.apache.doris.qe.StmtExecutor;
+
+import com.google.common.collect.Lists;
+
+import java.util.List;
+
+/**
+ * show triggers command
+ */
+public class ShowTriggersCommand extends ShowCommand {
+    private static final ShowResultSetMetaData META_DATA =
+            ShowResultSetMetaData.builder()
+                    .addColumn(new Column("Trigger", ScalarType.createVarchar(64)))
+                    .addColumn(new Column("Event", ScalarType.createVarchar(10)))
+                    .addColumn(new Column("Table", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("Statement", ScalarType.createVarchar(64)))
+                    .addColumn(new Column("Timing", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("Created", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("sql_mode", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("Definer", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("character_set_client", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("collation_connection", ScalarType.createVarchar(80)))
+                    .addColumn(new Column("Database Collation", ScalarType.createVarchar(80)))
+                    .build();
+
+    public ShowTriggersCommand() {
+        super(PlanType.SHOW_TRIGGERS_COMMAND);
+    }
+
+    @Override
+    public <R, C> R accept(PlanVisitor<R, C> visitor, C context) {
+        return visitor.visitShowTriggersCommand(this, context);
+    }
+
+    @Override
+    public ShowResultSet doRun(ConnectContext ctx, StmtExecutor executor) throws Exception {
+        List<List<String>> rowSet = Lists.newArrayList();
+        return new ShowResultSet(META_DATA, rowSet);
+    }
+}

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/visitor/CommandVisitor.java

@@ -70,6 +70,7 @@
 import org.apache.doris.nereids.trees.plans.commands.ShowSqlBlockRuleCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowStorageEnginesCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowTableIdCommand;
+import org.apache.doris.nereids.trees.plans.commands.ShowTriggersCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowVariablesCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowViewCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowWhiteListCommand;
@@ -295,6 +296,10 @@ default R visitShowPluginsCommand(ShowPluginsCommand showPluginsCommand, C conte
         return visitCommand(showPluginsCommand, context);
     }
 
+    default R visitShowTriggersCommand(ShowTriggersCommand showTriggersCommand, C context) {
+        return visitCommand(showTriggersCommand, context);
+    }
+
     default R visitShowRepositoriesCommand(ShowRepositoriesCommand showRepositoriesCommand, C context) {
         return visitCommand(showRepositoriesCommand, context);
     }

regression-test/suites/nereids_p0/show/test_show_commands_nereids.groovy

@@ -25,4 +25,6 @@ suite("test_show_commands_nereids") {
     checkNereidsExecute("""show frontends;""")
     checkNereidsExecute("""show backends;""")
     checkNereidsExecute("""show whitelist;""")
+    checkNereidsExecute("""show triggers;""")
+
 }