[branch-1.2](chore)support statement to show views from database

docs/en/docs/sql-manual/sql-reference/Show-Statements/SHOW-VIEWS.md

@@ -0,0 +1,78 @@
+---
+{ 
+    "title": "SHOW-VIEWS",
+    "language": "en"
+}
+---
+
+<!--
+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.
+-->
+
+## SHOW-VIEWS
+
+### Name
+
+SHOW VIEWS
+
+### Description
+
+This statement is used to display all logical views under the current db
+
+grammar:
+
+```sql
+SHOW [FULL] VIEWS [LIKE]
+````
+
+illustrate:
+
+1. LIKE: Fuzzy query can be performed according to the table name
+
+### Example
+
+  1. Desplay all views under DB
+
+    ```sql
+    MySQL [test]> show views;
+    +----------------+
+    | Tables_in_test |
+    +----------------+
+    | t1_view        |
+    | t2_view        |
+    +----------------+
+    2 rows in set (0.00 sec)
+    ```
+
+2. Fuzzy query by view name
+
+    ```sql
+    MySQL [test]> show views like '%t1%';
+    +----------------+
+    | Tables_in_test |
+    +----------------+
+    | t1_view        |
+    +----------------+
+    1 row in set (0.01 sec)
+    ```
+
+### Keywords
+
+    SHOW, VIEWS
+
+### Best Practice

docs/zh-CN/docs/sql-manual/sql-reference/Show-Statements/SHOW-VIEWS.md

@@ -0,0 +1,78 @@
+---
+{ 
+    "title": "SHOW-VIEWS",
+    "language": "zh-CN"
+}
+---
+
+<!--
+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.
+-->
+
+## SHOW-VIEWS
+
+### Name 
+
+SHOW VIEWS
+
+### Description
+
+该语句用于展示当前 db 下所有的 logical view
+
+语法：
+
+```sql
+SHOW [FULL] VIEWS [LIKE] | [WHERE where_condition]
+```
+
+说明:
+
+1. LIKE：可按照表名进行模糊查询
+
+### Example
+
+ 1. 查看DB下所有逻辑视图
+
+    ```sql
+    MySQL [test]> show views;
+    +----------------+
+    | Tables_in_test |
+    +----------------+
+    | t1_view        |
+    | t2_view        |
+    +----------------+
+    2 rows in set (0.00 sec)
+    ```
+
+2. 按照VIEW名进行模糊查询
+
+    ```sql
+    MySQL [test]> show views like '%t1%';
+    +----------------+
+    | Tables_in_test |
+    +----------------+
+    | t1_view        |
+    +----------------+
+    1 row in set (0.01 sec)
+    ```
+
+### Keywords
+
+    SHOW, VIEWS
+
+### Best Practice

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

@@ -43,6 +43,7 @@ import org.apache.doris.catalog.ArrayType;
 import org.apache.doris.catalog.MapType;
 import org.apache.doris.catalog.StructField;
 import org.apache.doris.catalog.StructType;
+import org.apache.doris.catalog.TableIf.TableType;
 import org.apache.doris.catalog.View;
 import org.apache.doris.common.AnalysisException;
 import org.apache.doris.common.FeConstants;
@@ -597,6 +598,7 @@ terminal String
     KW_VERBOSE,
     KW_VERSION,
     KW_VIEW,
+    KW_VIEWS,
     KW_WARNINGS,
     KW_WEEK,
     KW_WHEN,
@@ -3384,6 +3386,16 @@ show_param ::=
     {:
         RESULT = new ShowTableStmt(db, ctl, parser.isVerbose, parser.wild, parser.where);
     :}
+    /* show views */
+    | opt_full KW_VIEWS opt_db:db opt_wild_where
+    {:
+        RESULT = new ShowTableStmt(db, null, parser.isVerbose, TableType.VIEW, parser.wild, parser.where);
+    :}
+    /* show views */
+    | opt_full KW_VIEWS from_or_in ident:ctl DOT ident:db opt_wild_where
+    {:
+        RESULT = new ShowTableStmt(db, ctl, parser.isVerbose, TableType.VIEW, parser.wild, parser.where);
+    :}
     /* show table id */
     | KW_TABLE INTEGER_LITERAL:tableId
     {:
@@ -6852,6 +6864,8 @@ keyword ::=
     {: RESULT = id; :}
     | KW_VIEW:id
     {: RESULT = id; :}
+    | KW_VIEWS:id
+    {: RESULT = id; :}
     | KW_WARNINGS:id
     {: RESULT = id; :}
     | KW_WORK:id

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

@@ -20,6 +20,7 @@
 import org.apache.doris.catalog.Column;
 import org.apache.doris.catalog.InfoSchemaDb;
 import org.apache.doris.catalog.ScalarType;
+import org.apache.doris.catalog.TableIf.TableType;
 import org.apache.doris.cluster.ClusterNamespace;
 import org.apache.doris.common.AnalysisException;
 import org.apache.doris.common.ErrorCode;
@@ -42,8 +43,9 @@ public class ShowTableStmt extends ShowStmt {
             InfoSchemaDb.DATABASE_NAME, "tables");
     private String db;
     private String catalog;
-    private boolean isVerbose;
-    private String pattern;
+    private final boolean isVerbose;
+    private TableType type;
+    private final String pattern;
     private Expr where;
     private SelectStmt selectStmt;
 
@@ -63,6 +65,12 @@ public ShowTableStmt(String db, String catalog, boolean isVerbose, String patter
         this.catalog = catalog;
     }
 
+    public ShowTableStmt(String db, String catalog, boolean isVerbose, TableType type, String pattern,
+                         Expr where) {
+        this(db, catalog, isVerbose, pattern, where);
+        this.type = type;
+    }
+
     public String getDb() {
         return db;
     }
@@ -75,6 +83,10 @@ public boolean isVerbose() {
         return isVerbose;
     }
 
+    public TableType getType() {
+        return type;
+    }
+
     public String getPattern() {
         return pattern;
     }
@@ -122,6 +134,11 @@ public SelectStmt toSelectStmt(Analyzer analyzer) throws AnalysisException {
             selectList.addItem(item);
             aliasMap.put(new SlotRef(null, TYPE_COL), item.getExpr().clone(null));
         }
+        if (type != null) {
+            BinaryPredicate viewFilter = new BinaryPredicate(BinaryPredicate.Operator.EQ,
+                    new SlotRef(TABLE_NAME, "ENGINE"), new StringLiteral(type.toEngineName()));
+            where = CompoundPredicate.createConjunction(viewFilter, where);
+        }
         where = where.substitute(aliasMap);
         selectStmt = new SelectStmt(selectList,
                 new FromClause(Lists.newArrayList(new TableRef(TABLE_NAME, null))),
@@ -139,7 +156,18 @@ public String toSql() {
         if (isVerbose) {
             sb.append(" FULL");
         }
-        sb.append(" TABLES");
+        if (type != null) {
+            switch (type) {
+                // todo(only show views from now)
+                case VIEW:
+                    sb.append(" VIEWS");
+                    break;
+                default:
+                    sb.append(" TABLES");
+            }
+        } else {
+            sb.append(" TABLES");
+        }
         if (!Strings.isNullOrEmpty(db)) {
             if (!Strings.isNullOrEmpty(catalog)) {
                 sb.append(" FROM ").append(catalog);

fe/fe-core/src/main/java/org/apache/doris/qe/ShowExecutor.java

@@ -742,6 +742,9 @@ private void handleShowTable() throws AnalysisException {
                     CaseSensibility.TABLE.getCaseSensibility());
         }
         for (TableIf tbl : db.getTables()) {
+            if (showTableStmt.getType() != null && tbl.getType() != showTableStmt.getType()) {
+                continue;
+            }
             if (matcher != null && !matcher.match(tbl.getName())) {
                 continue;
             }

fe/fe-core/src/main/jflex/sql_scanner.flex

@@ -457,6 +457,7 @@ import org.apache.doris.qe.SqlModeHelper;
         keywordMap.put("verbose", new Integer(SqlParserSymbols.KW_VERBOSE));
         keywordMap.put("version", new Integer(SqlParserSymbols.KW_VERSION));
         keywordMap.put("view", new Integer(SqlParserSymbols.KW_VIEW));
+        keywordMap.put("views", new Integer(SqlParserSymbols.KW_VIEWS));
         keywordMap.put("warnings", new Integer(SqlParserSymbols.KW_WARNINGS));
         keywordMap.put("week", new Integer(SqlParserSymbols.KW_WEEK));
         keywordMap.put("when", new Integer(SqlParserSymbols.KW_WHEN));

fe/fe-core/src/test/java/org/apache/doris/analysis/ShowTableStmtTest.java

@@ -17,6 +17,7 @@
 
 package org.apache.doris.analysis;
 
+import org.apache.doris.catalog.TableIf.TableType;
 import org.apache.doris.common.AnalysisException;
 import org.apache.doris.mysql.privilege.MockedAuth;
 import org.apache.doris.mysql.privilege.PaloAuth;
@@ -68,6 +69,28 @@ public void testNormal() throws AnalysisException {
         Assert.assertEquals("Table_type", stmt.getMetaData().getColumn(1).getName());
     }
 
+    @Test
+    public void testShowViews() throws AnalysisException {
+        ShowTableStmt stmt = new ShowTableStmt("", null, false, TableType.VIEW,
+                null, null);
+        stmt.analyze(analyzer);
+        Assert.assertEquals("SHOW VIEWS FROM internal.testDb", stmt.toString());
+        Assert.assertEquals("testCluster:testDb", stmt.getDb());
+        Assert.assertEquals(TableType.VIEW, stmt.getType());
+        Assert.assertFalse(stmt.isVerbose());
+        Assert.assertEquals(1, stmt.getMetaData().getColumnCount());
+        Assert.assertEquals("Tables_in_testDb", stmt.getMetaData().getColumn(0).getName());
+
+        stmt = new ShowTableStmt("abc", null, true, TableType.VIEW, "bcd", null);
+        stmt.analyze(analyzer);
+        Assert.assertEquals("bcd", stmt.getPattern());
+        Assert.assertEquals("SHOW FULL VIEWS FROM internal.abc LIKE 'bcd'", stmt.toString());
+        Assert.assertEquals(3, stmt.getMetaData().getColumnCount());
+        Assert.assertEquals("Tables_in_abc", stmt.getMetaData().getColumn(0).getName());
+        Assert.assertEquals("Table_type", stmt.getMetaData().getColumn(1).getName());
+        Assert.assertEquals(TableType.VIEW, stmt.getType());
+    }
+
     @Test(expected = AnalysisException.class)
     public void testNoDb() throws AnalysisException {
         ShowTableStmt stmt = new ShowTableStmt("", null, false, null);

fe/fe-core/src/test/java/org/apache/doris/qe/ShowExecutorTest.java

@@ -334,6 +334,16 @@ public void testShowTable() throws AnalysisException {
         Assert.assertFalse(resultSet.next());
     }
 
+    @Test
+    public void testShowViews() throws AnalysisException {
+        ShowTableStmt stmt = new ShowTableStmt("testDb", null, false, TableType.VIEW,
+                null, null);
+        ShowExecutor executor = new ShowExecutor(ctx, stmt);
+        ShowResultSet resultSet = executor.execute();
+
+        Assert.assertFalse(resultSet.next());
+    }
+
     @Test
     public void testShowTableFromCatalog() throws AnalysisException {
         ShowTableStmt stmt = new ShowTableStmt("testCluster:testDb", "internal", false, null);