refactor sql parser about the desc and explain parts of the code

src/main/java/com/alibaba/druid/sql/ast/statement/SQLDescribeStatement.java

@@ -15,14 +15,24 @@
  */
 package com.alibaba.druid.sql.ast.statement;
 
+import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class SQLDescribeStatement extends SQLStatementImpl {
 
     protected SQLName object;
 
+    protected SQLName column;
+
+    // for odps
+    protected SQLObjectType objectType;
+    protected List<SQLExpr> partition = new ArrayList<SQLExpr>();
+
     public SQLName getObject() {
         return object;
     }
@@ -30,9 +40,40 @@ public class SQLDescribeStatement extends SQLStatementImpl {
     public void setObject(SQLName object) {
         this.object = object;
     }
-    
+
+    public SQLName getColumn() {
+        return column;
+    }
+
+    public void setColumn(SQLName column) {
+        if (column != null) {
+            column.setParent(this);
+        }
+        this.column = column;
+    }
+
+    public List<SQLExpr> getPartition() {
+        return partition;
+    }
+
+    public void setPartition(List<SQLExpr> partition) {
+        this.partition = partition;
+    }
+
+    public SQLObjectType getObjectType() {
+        return objectType;
+    }
+
+    public void setObjectType(SQLObjectType objectType) {
+        this.objectType = objectType;
+    }
+
     @Override
     protected void accept0(SQLASTVisitor visitor) {
-        throw new UnsupportedOperationException(this.getClass().getName());
+        if (visitor.visit(this)) {
+            acceptChild(visitor, object);
+            acceptChild(visitor, column);
+        }
+        visitor.endVisit(this);
     }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/statement/MySqlExplainStatement.java

@@ -33,9 +33,7 @@ public class MySqlExplainStatement extends SQLExplainStatement implements MySqlS
     private SQLName columnName;
     private SQLExpr wild;
 
-    private MySqlExplainType type;
-
-    private MySqlFormatName formatName;
+    private String format;
 
     private SQLExpr connectionId;
 
@@ -106,20 +104,12 @@ public class MySqlExplainStatement extends SQLExplainStatement implements MySqlS
         this.wild = wild;
     }
 
-    public MySqlExplainType getType() {
-        return type;
+    public String getFormat() {
+        return format;
     }
 
-    public void setType(MySqlExplainType type) {
-        this.type = type;
-    }
-
-    public MySqlFormatName getFormatName() {
-        return formatName;
-    }
-
-    public void setFormatName(MySqlFormatName formatName) {
-        this.formatName = formatName;
+    public void setFormat(String format) {
+        this.format = format;
     }
 
     public SQLExpr getConnectionId() {

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java

@@ -654,7 +654,7 @@ public class MySqlStatementParser extends SQLStatementParser {
         }
 
         if (lexer.token() == Token.EXPLAIN) {
-            MySqlExplainStatement stmt = this.parseExplain();
+            SQLStatement stmt = this.parseExplain();
             statementList.add(stmt);
             return true;
         }
@@ -829,44 +829,40 @@ public class MySqlStatementParser extends SQLStatementParser {
 
 
     private MySqlExplainStatement parseExplain(MySqlExplainStatement explain) {
+
+        if (lexer.token() == Token.HINT) {
+            List<SQLCommentHint> hints = this.exprParser.parseHints();
+            explain.setHints(hints);
+        }
         // see https://dev.mysql.com/doc/refman/5.7/en/explain.html
 
-        boolean extended = lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(EXTENDED);
-        boolean partitions = lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(PARTITIONS);
-        boolean format = lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(FORMAT);
-        boolean type = extended || partitions || format;
-        boolean forConnection = lexer.token() == Token.FOR;
-        boolean table = lexer.token() == Token.IDENTIFIER && !type && !forConnection;
+        boolean table = false;
+        if (lexer.token() == Token.IDENTIFIER) {
+             String stringVal = lexer.stringVal();
 
-        // tbl_name [col_name | wild]
-        if (table) {
-            explain.setTableName(exprParser.name());
-            if (lexer.token() == Token.IDENTIFIER) {
-                explain.setColumnName(exprParser.name());
-            } else if (lexer.token() == Token.LITERAL_CHARS) {
-                explain.setWild(exprParser.expr());
-            }
-        } else if (type) {
-            // [explain_type]
-            if (extended) {
-                explain.setType(MySqlExplainType.EXTENDED);
-            } else if (partitions) {
-                explain.setType(MySqlExplainType.PARTITIONS);
-            } else if (format) {
-                explain.setType(MySqlExplainType.FORMAT);
-                lexer.nextToken();
-                accept(Token.EQ);
-                if (lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(TRADITIONAL)) {
-                    explain.setFormatName(MySqlFormatName.TRADITIONAL);
-                } else if (lexer.token() == Token.IDENTIFIER && lexer.stringVal().equalsIgnoreCase(JSON)) {
-                    explain.setFormatName(MySqlFormatName.JSON);
-                }
-            }
+             if (stringVal.equalsIgnoreCase(EXTENDED)
+                     || stringVal.equalsIgnoreCase(PARTITIONS)) {
+                 explain.setType(stringVal);
+                 lexer.nextToken();
+             } else if (stringVal.equalsIgnoreCase(FORMAT)) {
+                 explain.setType(stringVal);
+                 lexer.nextToken();
+                 accept(Token.EQ);
 
-            lexer.nextToken();
+                 String format = lexer.stringVal();
+                 explain.setFormat(format);
+                 accept(Token.IDENTIFIER);
+             } else {
+                 explain.setTableName(exprParser.name());
+                 if (lexer.token() == Token.IDENTIFIER) {
+                     explain.setColumnName(exprParser.name());
+                 } else if (lexer.token() == Token.LITERAL_CHARS) {
+                     explain.setWild(exprParser.expr());
+                 }
+                 table = true;
+             }
         }
 
-        // {explainable_stmt | FOR CONNECTION connection_id}
         if (lexer.token() == Token.FOR) {
             lexer.nextToken();
             acceptIdentifier(CONNECTION);

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -1723,12 +1723,13 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
             }
         } else {
             // [explain_type]
-            if (x.getType() != null) {
-                print0(ucase ? x.getType().name() : x.getType().name().toLowerCase());
+            String type = x.getType();
+            if (type != null) {
+                print0(type);
                 print(' ');
-                if (x.getType() == MySqlExplainType.FORMAT) {
+                if ("format".equalsIgnoreCase(type)) {
                     print0("= ");
-                    print(ucase ? x.getFormatName().name() : x.getFormatName().name().toLowerCase());
+                    print0(x.getFormat());
                     print(' ');
                 }
             }

src/main/java/com/alibaba/druid/sql/dialect/odps/ast/OdpsDescStmt.java

@@ -1,66 +0,0 @@
-/*
- * Copyright 1999-2017 Alibaba Group Holding Ltd.
- *
- * Licensed 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 com.alibaba.druid.sql.dialect.odps.ast;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import com.alibaba.druid.sql.ast.SQLExpr;
-import com.alibaba.druid.sql.ast.statement.SQLDescribeStatement;
-import com.alibaba.druid.sql.ast.statement.SQLObjectType;
-import com.alibaba.druid.sql.dialect.odps.visitor.OdpsASTVisitor;
-import com.alibaba.druid.sql.visitor.SQLASTVisitor;
-import com.alibaba.druid.util.JdbcConstants;
-
-public class OdpsDescStmt extends SQLDescribeStatement {
-
-    private SQLObjectType objectType;
-
-    private List<SQLExpr> partition = new ArrayList<SQLExpr>();
-
-    public OdpsDescStmt() {
-        this.setDbType(JdbcConstants.ODPS);
-    }
-
-    @Override
-    protected void accept0(SQLASTVisitor visitor) {
-        accept0((OdpsASTVisitor) visitor);
-    }
-
-    protected void accept0(OdpsASTVisitor visitor) {
-        if (visitor.visit(this)) {
-            acceptChild(visitor, object);
-        }
-        visitor.endVisit(this);
-    }
-
-    public SQLObjectType getObjectType() {
-        return objectType;
-    }
-
-    public void setObjectType(SQLObjectType objectType) {
-        this.objectType = objectType;
-    }
-
-    public List<SQLExpr> getPartition() {
-        return partition;
-    }
-
-    public void setPartition(List<SQLExpr> partition) {
-        this.partition = partition;
-    }
-
-}

src/main/java/com/alibaba/druid/sql/dialect/odps/parser/OdpsStatementParser.java

@@ -33,7 +33,6 @@ import com.alibaba.druid.sql.ast.statement.SQLShowTablesStatement;
 import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsAddStatisticStatement;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsAnalyzeTableStatement;
-import com.alibaba.druid.sql.dialect.odps.ast.OdpsDescStmt;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsGrantStmt;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsInsert;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsInsertStatement;
@@ -179,7 +178,7 @@ public class OdpsStatementParser extends SQLStatementParser {
         }
 
         if (lexer.token() == Token.DESC || identifierEquals("DESCRIBE")) {
-            OdpsDescStmt stmt = parseDescribe();
+            SQLStatement stmt = parseDescribe();
             statementList.add(stmt);
             return true;
         }
@@ -589,42 +588,4 @@ public class OdpsStatementParser extends SQLStatementParser {
             break;
         }
     }
-
-    public OdpsDescStmt parseDescribe() {
-        if (lexer.token() == Token.DESC || identifierEquals("DESCRIBE")) {
-            lexer.nextToken();
-        } else {
-            throw new ParserException("expect DESC, actual " + lexer.token());
-        }
-
-        OdpsDescStmt stmt = new OdpsDescStmt();
-        if (identifierEquals("ROLE")) {
-            lexer.nextToken();
-            stmt.setObjectType(SQLObjectType.ROLE);
-        } else if (identifierEquals("PACKAGE")) {
-            lexer.nextToken();
-            stmt.setObjectType(SQLObjectType.PACKAGE);
-        } else if (identifierEquals("INSTANCE")) {
-            lexer.nextToken();
-            stmt.setObjectType(SQLObjectType.INSTANCE);
-        }
-        stmt.setObject(this.exprParser.name());
-
-        if (lexer.token() == Token.PARTITION) {
-            lexer.nextToken();
-            this.accept(Token.LPAREN);
-            for (;;) {
-                stmt.getPartition().add(this.exprParser.expr());
-                if (lexer.token() == Token.COMMA) {
-                    lexer.nextToken();
-                    continue;
-                }
-                if (lexer.token() == Token.RPAREN) {
-                    lexer.nextToken();
-                    break;
-                }
-            }
-        }
-        return stmt;
-    }
 }

src/main/java/com/alibaba/druid/sql/dialect/odps/visitor/OdpsASTVisitor.java

@@ -104,10 +104,6 @@ public interface OdpsASTVisitor extends SQLASTVisitor {
     
     boolean visit(OdpsGrantStmt x);
     
-    void endVisit(OdpsDescStmt x);
-    
-    boolean visit(OdpsDescStmt x);
-    
     void endVisit(OdpsLateralViewTableSource x);
     
     boolean visit(OdpsLateralViewTableSource x);

src/main/java/com/alibaba/druid/sql/dialect/odps/visitor/OdpsASTVisitorAdapter.java

@@ -231,16 +231,6 @@ public class OdpsASTVisitorAdapter extends SQLASTVisitorAdapter implements OdpsA
         return true;
     }
 
-    @Override
-    public void endVisit(OdpsDescStmt x) {
-        
-    }
-
-    @Override
-    public boolean visit(OdpsDescStmt x) {
-        return true;
-    }
-    
     @Override
     public void endVisit(OdpsLateralViewTableSource x) {
         

src/main/java/com/alibaba/druid/sql/dialect/odps/visitor/OdpsOutputVisitor.java

@@ -815,31 +815,6 @@ public class OdpsOutputVisitor extends SQLASTOutputVisitor implements OdpsASTVis
         return false;
     }
 
-    @Override
-    public void endVisit(OdpsDescStmt x) {
-        
-    }
-
-    @Override
-    public boolean visit(OdpsDescStmt x) {
-        print0(ucase ? "DESC " : "desc ");
-        if (x.getObjectType() != null) {
-            print0(x.getObjectType().name());
-            print(' ');
-        }
-        
-        if(x.getObject() != null) {
-            x.getObject().accept(this);
-        }
-        
-        if (x.getPartition().size() > 0) {
-            print0(ucase ? " PARTITION (" : " partition (");
-            printAndAccept(x.getPartition(), ", ");
-            print(')');
-        }
-        return false;
-    }
-
     @Override
     public void endVisit(OdpsLateralViewTableSource x) {
         

src/main/java/com/alibaba/druid/sql/dialect/odps/visitor/OdpsSchemaStatVisitor.java

@@ -264,16 +264,6 @@ public class OdpsSchemaStatVisitor extends SchemaStatVisitor implements OdpsASTV
         return super.visit((SQLGrantStatement) x);
     }
 
-    @Override
-    public void endVisit(OdpsDescStmt x) {
-        
-    }
-
-    @Override
-    public boolean visit(OdpsDescStmt x) {
-        return true;
-    }
-    
     @Override
     public void endVisit(OdpsLateralViewTableSource x) {
         

src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java

@@ -2352,4 +2352,48 @@ public class SQLStatementParser extends SQLParser {
     public void parseHints(List<SQLHint> hints) {
         this.getExprParser().parseHints(hints);
     }
+
+    public SQLStatement parseDescribe() {
+        if (lexer.token() == Token.DESC || identifierEquals("DESCRIBE")) {
+            lexer.nextToken();
+        } else {
+            throw new ParserException("expect DESC, actual " + lexer.token());
+        }
+
+        SQLDescribeStatement stmt = new SQLDescribeStatement();
+        stmt.setDbType(dbType);
+
+        if (identifierEquals("ROLE")) {
+            lexer.nextToken();
+            stmt.setObjectType(SQLObjectType.ROLE);
+        } else if (identifierEquals("PACKAGE")) {
+            lexer.nextToken();
+            stmt.setObjectType(SQLObjectType.PACKAGE);
+        } else if (identifierEquals("INSTANCE")) {
+            lexer.nextToken();
+            stmt.setObjectType(SQLObjectType.INSTANCE);
+        }
+        stmt.setObject(this.exprParser.name());
+
+        Token token = lexer.token();
+        if (token == Token.PARTITION) {
+            lexer.nextToken();
+            this.accept(Token.LPAREN);
+            for (;;) {
+                stmt.getPartition().add(this.exprParser.expr());
+                if (lexer.token() == Token.COMMA) {
+                    lexer.nextToken();
+                    continue;
+                }
+                if (lexer.token() == Token.RPAREN) {
+                    lexer.nextToken();
+                    break;
+                }
+            }
+        } else if (token == Token.IDENTIFIER) {
+            SQLName column = this.exprParser.name();
+            stmt.setColumn(column);
+        }
+        return stmt;
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/SQLASTOutputVisitor.java

@@ -3929,4 +3929,23 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
 
         return false;
     }
+
+    public boolean visit(SQLDescribeStatement x) {
+        print0(ucase ? "DESC " : "desc ");
+        if (x.getObjectType() != null) {
+            print0(x.getObjectType().name());
+            print(' ');
+        }
+
+        if(x.getObject() != null) {
+            x.getObject().accept(this);
+        }
+
+        if (x.getPartition().size() > 0) {
+            print0(ucase ? " PARTITION (" : " partition (");
+            printAndAccept(x.getPartition(), ", ");
+            print(')');
+        }
+        return false;
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/SQLASTVisitor.java

@@ -685,4 +685,7 @@ public interface SQLASTVisitor {
 
     void endVisit(SQLStartTransactionStatement x);
     boolean visit(SQLStartTransactionStatement x);
+
+    void endVisit(SQLDescribeStatement x);
+    boolean visit(SQLDescribeStatement x);
 }

src/main/java/com/alibaba/druid/sql/visitor/SQLASTVisitorAdapter.java

@@ -1555,7 +1555,6 @@ public class SQLASTVisitorAdapter implements SQLASTVisitor {
 
     }
 
-
     @Override
     public void endVisit(SQLStartTransactionStatement x) {
 
@@ -1565,4 +1564,14 @@ public class SQLASTVisitorAdapter implements SQLASTVisitor {
     public boolean visit(SQLStartTransactionStatement x) {
         return true;
     }
+
+    @Override
+    public void endVisit(SQLDescribeStatement x) {
+
+    }
+
+    @Override
+    public boolean visit(SQLDescribeStatement x) {
+        return true;
+    }
 }

src/main/java/com/alibaba/druid/sql/visitor/SchemaStatVisitor.java

@@ -53,6 +53,7 @@ import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
 import com.alibaba.druid.sql.ast.expr.SQLSequenceExpr;
 import com.alibaba.druid.sql.ast.statement.*;
 import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlExpr;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlExplainStatement;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitorAdapter;
 import com.alibaba.druid.sql.dialect.odps.ast.OdpsValuesTableSource;
 import com.alibaba.druid.sql.dialect.oracle.ast.expr.OracleExpr;
@@ -1941,5 +1942,29 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
         tableStat.incrementDropIndexCount();
         return false;
     }
+
+    @Override
+    public boolean visit(SQLDescribeStatement x) {
+        String tableName = x.getObject().toString();
+
+        TableStat tableStat = this.getTableStat(tableName);
+        tableStat.incrementDropIndexCount();
+
+        SQLName column = x.getColumn();
+        if (column != null) {
+            String columnName = column.toString();
+            this.addColumn(tableName, columnName);
+        }
+        return false;
+    }
+
+    public boolean visit(SQLExplainStatement x) {
+        if (x.getStatement() != null) {
+            accept(x.getStatement());
+        }
+
+        return false;
+    }
+    //
     //
 }

src/main/java/com/alibaba/druid/wall/spi/WallVisitorUtils.java

@@ -48,45 +48,8 @@ import com.alibaba.druid.sql.ast.expr.SQLQueryExpr;
 import com.alibaba.druid.sql.ast.expr.SQLUnaryExpr;
 import com.alibaba.druid.sql.ast.expr.SQLValuableExpr;
 import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
-import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
-import com.alibaba.druid.sql.ast.statement.SQLBlockStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCallStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCreateIndexStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCreateSequenceStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCreateTriggerStatement;
-import com.alibaba.druid.sql.ast.statement.SQLCreateViewStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropIndexStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropProcedureStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropSequenceStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropTableStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropTriggerStatement;
-import com.alibaba.druid.sql.ast.statement.SQLDropViewStatement;
-import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLInsertInto;
-import com.alibaba.druid.sql.ast.statement.SQLInsertStatement;
+import com.alibaba.druid.sql.ast.statement.*;
 import com.alibaba.druid.sql.ast.statement.SQLInsertStatement.ValuesClause;
-import com.alibaba.druid.sql.ast.statement.SQLJoinTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLMergeStatement;
-import com.alibaba.druid.sql.ast.statement.SQLRollbackStatement;
-import com.alibaba.druid.sql.ast.statement.SQLSelect;
-import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
-import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
-import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
-import com.alibaba.druid.sql.ast.statement.SQLSetStatement;
-import com.alibaba.druid.sql.ast.statement.SQLShowTablesStatement;
-import com.alibaba.druid.sql.ast.statement.SQLStartTransactionStatement;
-import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLTableSource;
-import com.alibaba.druid.sql.ast.statement.SQLTruncateStatement;
-import com.alibaba.druid.sql.ast.statement.SQLUnionOperator;
-import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
-import com.alibaba.druid.sql.ast.statement.SQLUpdateSetItem;
-import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
-import com.alibaba.druid.sql.ast.statement.SQLUseStatement;
 import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlOrderingExpr;
 import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlOutFileExpr;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlCommitStatement;
@@ -2503,7 +2466,8 @@ public class WallVisitorUtils {
             allow = config.isReplaceAllow();
             denyMessage = "replace not allow";
             errorCode = ErrorCode.REPLACE_NOT_ALLOW;
-        } else if (x instanceof MySqlExplainStatement && ((MySqlExplainStatement)x).isDescribe()) {
+        } else if (x instanceof SQLDescribeStatement
+            || (x instanceof MySqlExplainStatement && ((MySqlExplainStatement)x).isDescribe())) {
             allow = config.isDescribeAllow();
             denyMessage = "describe not allow";
             errorCode = ErrorCode.DESC_NOT_ALLOW;