improved h2 support, fix #3923

src/main/java/com/alibaba/druid/sql/dialect/h2/parser/H2ExprParser.java

@@ -15,9 +15,14 @@
  */
 package com.alibaba.druid.sql.dialect.h2.parser;
 
+import com.alibaba.druid.sql.ast.expr.SQLDefaultExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
+import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.parser.Lexer;
 import com.alibaba.druid.sql.parser.SQLExprParser;
 import com.alibaba.druid.sql.parser.SQLParserFeature;
+import com.alibaba.druid.sql.parser.Token;
 import com.alibaba.druid.util.FnvHash;
 
 import java.util.Arrays;
@@ -50,7 +55,42 @@ public class H2ExprParser extends SQLExprParser {
 
     public H2ExprParser(Lexer lexer){
         super(lexer);
+        dbType = lexer.getDbType();
         this.aggregateFunctions = AGGREGATE_FUNCTIONS;
         this.aggregateFunctionHashCodes = AGGREGATE_FUNCTIONS_CODES;
     }
+
+    public SQLColumnDefinition parseColumnRest(SQLColumnDefinition column) {
+        column = super.parseColumnRest(column);
+
+        if (lexer.identifierEquals(FnvHash.Constants.GENERATED)) {
+            lexer.nextToken();
+            if (lexer.token() == Token.BY) {
+                lexer.nextToken();
+                accept(Token.DEFAULT);
+                column.setGeneratedAlawsAs(new SQLDefaultExpr());
+            } else {
+                acceptIdentifier("ALWAYS");
+                column.setGeneratedAlawsAs(new SQLIdentifierExpr("ALWAYS"));
+            }
+            accept(Token.AS);
+            acceptIdentifier("IDENTITY");
+
+            SQLColumnDefinition.Identity identity = new SQLColumnDefinition.Identity();
+            if (lexer.token() == Token.LPAREN) {
+                lexer.nextToken();
+
+                SQLIntegerExpr seed = (SQLIntegerExpr) this.primary();
+                accept(Token.COMMA);
+                SQLIntegerExpr increment = (SQLIntegerExpr) this.primary();
+                accept(Token.RPAREN);
+
+                identity.setSeed((Integer) seed.getNumber());
+                identity.setIncrement((Integer) increment.getNumber());
+            }
+            column.setIdentity(identity);
+        }
+
+        return column;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/h2/parser/H2Lexer.java

@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.dialect.h2.parser;
 
+import com.alibaba.druid.DbType;
 import com.alibaba.druid.sql.parser.Keywords;
 import com.alibaba.druid.sql.parser.Lexer;
 import com.alibaba.druid.sql.parser.SQLParserFeature;
@@ -45,12 +46,12 @@ public class H2Lexer extends Lexer {
     }
 
     public H2Lexer(String input){
-        super(input);
+        super(input, null, DbType.h2);
         super.keywods = DEFAULT_H2_KEYWORDS;
     }
 
     public H2Lexer(String input, SQLParserFeature... features){
-        super(input);
+        super(input, null, DbType.h2);
         super.keywods = DEFAULT_H2_KEYWORDS;
         for (SQLParserFeature feature : features) {
             config(feature, true);

src/main/java/com/alibaba/druid/sql/dialect/h2/visitor/H2OutputVisitor.java

@@ -26,7 +26,7 @@ import java.util.List;
 
 public class H2OutputVisitor extends SQLASTOutputVisitor implements H2ASTVisitor {
     public H2OutputVisitor(Appendable appender) {
-        super(appender);
+        super(appender, DbType.h2);
     }
 
     public H2OutputVisitor(Appendable appender, DbType dbType) {
@@ -35,6 +35,7 @@ public class H2OutputVisitor extends SQLASTOutputVisitor implements H2ASTVisitor
 
     public H2OutputVisitor(Appendable appender, boolean parameterized) {
         super(appender, parameterized);
+        dbType = DbType.h2;
     }
 
     public boolean visit(SQLReplaceStatement x) {

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

@@ -33,6 +33,7 @@ public class SQLCreateTableParser extends SQLDDLParser {
 
     public SQLCreateTableParser(SQLExprParser exprParser) {
         super(exprParser);
+        dbType = exprParser.dbType;
     }
 
     public SQLCreateTableStatement parseCreateTable() {
@@ -51,6 +52,7 @@ public class SQLCreateTableParser extends SQLDDLParser {
 
     public SQLCreateTableStatement parseCreateTable(boolean acceptCreate) {
         SQLCreateTableStatement createTable = newCreateStatement();
+        createTable.setDbType(getDbType());
 
         if (acceptCreate) {
             if (lexer.hasComment() && lexer.isKeepComments()) {
@@ -108,7 +110,7 @@ public class SQLCreateTableParser extends SQLDDLParser {
                     createTable.getTableElementList().add(element);
                 } else if (token == Token.IDENTIFIER //
                            || token == Token.LITERAL_ALIAS) {
-                    SQLColumnDefinition column = this.exprParser.parseColumn();
+                    SQLColumnDefinition column = this.exprParser.parseColumn(createTable);
                     column.setParent(createTable);
                     createTable.getTableElementList().add(column);
                 } else if (token == Token.PRIMARY //

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

@@ -3229,7 +3229,11 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
 
         SQLColumnDefinition.Identity identity = x.getIdentity();
         if (identity != null) {
-            print(' ');
+            if (dbType == DbType.h2) {
+                print0(ucase ? " AS " : " as ");
+            } else {
+                print(' ');
+            }
             identity.accept(this);
         }
 

src/test/java/com/alibaba/druid/bvt/sql/h2/H2_CreateTableTest_1.java

@@ -0,0 +1,47 @@
+/*
+ * 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.bvt.sql.h2;
+
+import com.alibaba.druid.DbType;
+import com.alibaba.druid.sql.OracleTest;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.oracle.visitor.OracleSchemaStatVisitor;
+import com.alibaba.druid.util.JdbcConstants;
+import org.junit.Assert;
+
+import java.util.List;
+
+public class H2_CreateTableTest_1 extends OracleTest {
+
+    public void test_0() throws Exception {
+        String sql = //
+                "CREATE TABLE tutorials_tbl ( \n" +
+                        "   id bigint generated by default as identity, \n" +
+                        "   title VARCHAR(50) NOT NULL, \n" +
+                        "   author VARCHAR(20) NOT NULL, \n" +
+                        "   submission_date DATE \n" +
+                        ");"; //
+
+        SQLStatement stmt = SQLUtils.parseSingleStatement(sql, DbType.h2);
+        assertEquals("CREATE TABLE tutorials_tbl (\n" +
+                "\tid bigint GENERATED ALWAYS AS DEFAULT AS IDENTITY,\n" +
+                "\ttitle VARCHAR(50) NOT NULL,\n" +
+                "\tauthor VARCHAR(20) NOT NULL,\n" +
+                "\tsubmission_date DATE\n" +
+                ");", stmt.toString());
+    }
+}