improved sql parser for postgresql, support create table inherits

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

@@ -30,12 +30,15 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
 
     protected List<SQLTableElement> tableElementList = new ArrayList<SQLTableElement>();
 
+    // for postgresql
+    private SQLExprTableSource      inherits;
+
     public SQLCreateTableStatement(){
 
     }
-    
+
     public SQLCreateTableStatement(String dbType){
-        super (dbType);
+        super(dbType);
     }
 
     public SQLName getName() {
@@ -76,7 +79,7 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
     public List<SQLTableElement> getTableElementList() {
         return tableElementList;
     }
-    
+
     public boolean isIfNotExiists() {
         return ifNotExiists;
     }
@@ -85,26 +88,15 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
         this.ifNotExiists = ifNotExiists;
     }
 
-    @Override
-    public void output(StringBuffer buf) {
-        buf.append("CREATE TABLE ");
-        if (Type.GLOBAL_TEMPORARY.equals(this.type)) {
-            buf.append("GLOBAL TEMPORARY ");
-        } else if (Type.LOCAL_TEMPORARY.equals(this.type)) {
-            buf.append("LOCAL TEMPORARY ");
-        }
+    public SQLExprTableSource getInherits() {
+        return inherits;
+    }
 
-        this.tableSource.output(buf);
-        buf.append(" ");
-
-        buf.append("(");
-        for (int i = 0, size = tableElementList.size(); i < size; ++i) {
-            if (i != 0) {
-                buf.append(", ");
-            }
-            tableElementList.get(i).output(buf);
+    public void setInherits(SQLExprTableSource inherits) {
+        if (inherits != null) {
+            inherits.setParent(this);
         }
-        buf.append(")");
+        this.inherits = inherits;
     }
 
     @Override
@@ -112,6 +104,7 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
         if (visitor.visit(this)) {
             this.acceptChild(visitor, tableSource);
             this.acceptChild(visitor, tableElementList);
+            this.acceptChild(visitor, inherits);
         }
         visitor.endVisit(this);
     }

src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGCreateTableStatement.java

@@ -0,0 +1,14 @@
+package com.alibaba.druid.sql.dialect.postgresql.ast.stmt;
+
+import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
+import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class PGCreateTableStatement extends SQLCreateTableStatement {
+    private SQLExprTableSource inherits;
+
+    public PGCreateTableStatement(){
+        super(JdbcConstants.POSTGRESQL);
+    }
+
+}

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

@@ -15,9 +15,11 @@
  */
 package com.alibaba.druid.sql.parser;
 
+import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
+import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.ast.statement.SQLTableElement;
 
 public class SQLCreateTableParser extends SQLDDLParser {
@@ -109,6 +111,13 @@ public class SQLCreateTableParser extends SQLDDLParser {
 
             accept(Token.RPAREN);
 
+            if (identifierEquals("INHERITS")) {
+                lexer.nextToken();
+                accept(Token.LPAREN);
+                SQLName inherits = this.exprParser.name();
+                createTable.setInherits(new SQLExprTableSource(inherits));
+                accept(Token.RPAREN);
+            }
         }
 
         return createTable;

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

@@ -1058,6 +1058,12 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Printab
             println();
             print(")");
         }
+        
+        if (x.getInherits() != null) {
+            print(" INHERITS (");
+            x.getInherits().accept(this);
+            print(")");
+        }
 
         return false;
     }

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

@@ -1107,6 +1107,10 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
         accept(x.getTableElementList());
 
         restoreCurrentTable(x);
+        
+        if (x.getInherits() != null) {
+            x.getInherits().accept(this);
+        }
 
         return false;
     }