[enhance](mtmv)show create materialized view (#36188)

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

@@ -114,6 +114,7 @@ statementBase
     | PAUSE MATERIALIZED VIEW JOB ON mvName=multipartIdentifier      #pauseMTMV
     | RESUME MATERIALIZED VIEW JOB ON mvName=multipartIdentifier      #resumeMTMV
     | CANCEL MATERIALIZED VIEW TASK taskId=INTEGER_VALUE ON mvName=multipartIdentifier      #cancelMTMVTask
+    | SHOW CREATE MATERIALIZED VIEW mvName=multipartIdentifier #showCreateMTMV
     | ALTER TABLE table=multipartIdentifier
         ADD CONSTRAINT constraintName=errorCapturingIdentifier
         constraint                                                        #addConstraint

fe/fe-core/src/main/cup/sql_parser.cup

@@ -4052,6 +4052,10 @@ show_param ::=
     {:
         RESULT = new ShowCreateTableStmt(table, true, false);
     :}
+    | KW_CREATE KW_MATERIALIZED KW_VIEW table_name:table
+    {:
+        RESULT = new ShowCreateMTMVStmt(table);
+    :}
     /* Create database */
     | KW_CREATE KW_DATABASE db_name:db
     {:

fe/fe-core/src/main/java/org/apache/doris/analysis/ShowCreateMTMVStmt.java

@@ -0,0 +1,95 @@
+// 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.analysis;
+
+import org.apache.doris.catalog.Column;
+import org.apache.doris.catalog.Env;
+import org.apache.doris.catalog.MTMV;
+import org.apache.doris.catalog.ScalarType;
+import org.apache.doris.catalog.TableIf;
+import org.apache.doris.common.AnalysisException;
+import org.apache.doris.common.ErrorCode;
+import org.apache.doris.common.ErrorReport;
+import org.apache.doris.mysql.privilege.PrivPredicate;
+import org.apache.doris.qe.ConnectContext;
+import org.apache.doris.qe.ShowResultSetMetaData;
+
+// SHOW CREATE Materialized View statement.
+public class ShowCreateMTMVStmt extends ShowStmt {
+    private static final ShowResultSetMetaData META_DATA =
+            ShowResultSetMetaData.builder()
+                    .addColumn(new Column("Materialized View", ScalarType.createVarchar(20)))
+                    .addColumn(new Column("Create Materialized View", ScalarType.createVarchar(30)))
+                    .build();
+
+    private TableName tbl;
+
+    public ShowCreateMTMVStmt(TableName tbl) {
+        this.tbl = tbl;
+    }
+
+
+    public String getCtl() {
+        return tbl.getCtl();
+    }
+
+    public String getDb() {
+        return tbl.getDb();
+    }
+
+    public String getTable() {
+        return tbl.getTbl();
+    }
+
+    @Override
+    public void analyze(Analyzer analyzer) throws AnalysisException {
+        if (tbl == null) {
+            ErrorReport.reportAnalysisException(ErrorCode.ERR_NO_TABLES_USED);
+        }
+        tbl.analyze(analyzer);
+
+        TableIf tableIf = Env.getCurrentEnv().getCatalogMgr()
+                .getCatalogOrAnalysisException(tbl.getCtl())
+                .getDbOrAnalysisException(tbl.getDb()).getTableOrAnalysisException(tbl.getTbl());
+
+        if (!(tableIf instanceof MTMV)) {
+            ErrorReport.reportAnalysisException("only support async materialized view");
+        }
+
+        if (!Env.getCurrentEnv().getAccessManager().checkTblPriv(ConnectContext.get(), tbl.getCtl(), tbl.getDb(),
+                tbl.getTbl(), PrivPredicate.SHOW)) {
+            ErrorReport.reportAnalysisException(ErrorCode.ERR_TABLE_ACCESS_DENIED_ERROR,
+                    PrivPredicate.SHOW.getPrivs().toString(), getTable());
+        }
+    }
+
+    @Override
+    public String toSql() {
+        return "SHOW CREATE MATERIALIZED VIEW " + tbl;
+    }
+
+    @Override
+    public String toString() {
+        return toSql();
+    }
+
+    @Override
+    public ShowResultSetMetaData getMetaData() {
+        return META_DATA;
+    }
+}

fe/fe-core/src/main/java/org/apache/doris/analysis/ShowCreateTableStmt.java

@@ -19,6 +19,7 @@
 
 import org.apache.doris.catalog.Column;
 import org.apache.doris.catalog.Env;
+import org.apache.doris.catalog.MTMV;
 import org.apache.doris.catalog.ScalarType;
 import org.apache.doris.catalog.TableIf;
 import org.apache.doris.catalog.View;
@@ -109,6 +110,11 @@ public void analyze(Analyzer analyzer) throws AnalysisException {
                 .getCatalogOrAnalysisException(tbl.getCtl())
                 .getDbOrAnalysisException(tbl.getDb()).getTableOrAnalysisException(tbl.getTbl());
 
+        if (tableIf instanceof MTMV) {
+            ErrorReport.reportAnalysisException("not support async materialized view, "
+                    + "please use `show create materialized view`");
+        }
+
         PrivPredicate wanted;
         if (tableIf instanceof View) {
             wanted = PrivPredicate.SHOW_VIEW;