From 7393c725c2451d111bb3bec35f8e92ed73d1a8aa Mon Sep 17 00:00:00 2001
From: wenshao <szujobs@hotmail.com>
Date: Wed, 8 Nov 2017 23:25:28 +0800
Subject: [PATCH] bug fixed for SQLSelect.toString(). for issue #2096

---
 .../druid/sql/ast/statement/SQLSelect.java    | 21 +++++
 .../druid/bvt/sql/db2/DB2SelectTest_28.java   | 81 +++++++++++++++++++
 2 files changed, 102 insertions(+)
 create mode 100644 src/test/java/com/alibaba/druid/bvt/sql/db2/DB2SelectTest_28.java

diff --git a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
index 3d32fa2199..c3337a0549 100644
--- a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
+++ b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLSelect.java
@@ -21,6 +21,7 @@ import java.util.List;
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.*;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObject;
+import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 import com.alibaba.druid.util.JdbcConstants;
 
@@ -143,6 +144,26 @@ public class SQLSelect extends SQLObjectImpl {
         return true;
     }
 
+    public void output(StringBuffer buf) {
+        String dbType = null;
+
+        SQLObject parent = this.getParent();
+        if (parent instanceof SQLStatement) {
+            dbType = ((SQLStatement) parent).getDbType();
+        }
+
+        if (dbType == null && parent instanceof OracleSQLObject) {
+            dbType = JdbcConstants.ORACLE;
+        }
+
+        if (dbType == null && query instanceof SQLSelectQueryBlock) {
+            dbType = ((SQLSelectQueryBlock) query).dbType;
+        }
+
+        SQLASTOutputVisitor visitor = SQLUtils.createOutputVisitor(buf, dbType);
+        this.accept(visitor);
+    }
+
     public String toString() {
         SQLObject parent = this.getParent();
         if (parent instanceof SQLStatement) {
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/db2/DB2SelectTest_28.java b/src/test/java/com/alibaba/druid/bvt/sql/db2/DB2SelectTest_28.java
new file mode 100644
index 0000000000..ea3fa668a3
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/db2/DB2SelectTest_28.java
@@ -0,0 +1,81 @@
+/*
+ * 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.db2;
+
+import com.alibaba.druid.sql.DB2Test;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
+import com.alibaba.druid.sql.dialect.db2.parser.DB2StatementParser;
+import com.alibaba.druid.sql.dialect.db2.visitor.DB2SchemaStatVisitor;
+import com.alibaba.druid.stat.TableStat;
+import com.alibaba.druid.util.JdbcConstants;
+import org.junit.Assert;
+
+import java.util.List;
+
+public class DB2SelectTest_28 extends DB2Test {
+
+    public void test_0() throws Exception {
+        String sql = "select a from (select b from d)";
+
+        DB2StatementParser parser = new DB2StatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLSelectStatement stmt = (SQLSelectStatement) statementList.get(0);
+        assertEquals("SELECT a\n" +
+                        "FROM (\n" +
+                        "\tSELECT b\n" +
+                        "\tFROM d\n" +
+                        ")", stmt.getSelect().toString());
+
+        assertEquals("(SELECT b\n" +
+                "FROM d)", stmt.getSelect().getQueryBlock().getFrom().toString());
+
+        Assert.assertEquals(1, statementList.size());
+
+        DB2SchemaStatVisitor visitor = new DB2SchemaStatVisitor();
+        stmt.accept(visitor);
+
+        System.out.println("Tables : " + visitor.getTables());
+        System.out.println("fields : " + visitor.getColumns());
+//        System.out.println("coditions : " + visitor.getConditions());
+//        System.out.println("orderBy : " + visitor.getOrderByColumns());
+
+        Assert.assertEquals(1, visitor.getTables().size());
+        Assert.assertEquals(2, visitor.getColumns().size());
+        Assert.assertEquals(0, visitor.getConditions().size());
+
+        Assert.assertTrue(visitor.getTables().containsKey(new TableStat.Name("d")));
+
+//         Assert.assertTrue(visitor.getColumns().contains(new Column("DSN8B10.EMP", "WORKDEPT")));
+        // Assert.assertTrue(visitor.getColumns().contains(new Column("mytable", "first_name")));
+        // Assert.assertTrue(visitor.getColumns().contains(new Column("mytable", "full_name")));
+
+        Assert.assertEquals("SELECT a\n" +
+                        "FROM (\n" +
+                        "\tSELECT b\n" +
+                        "\tFROM d\n" +
+                        ")", //
+                            SQLUtils.toSQLString(stmt, JdbcConstants.DB2));
+        
+        Assert.assertEquals("select a\n" +
+                        "from (\n" +
+                        "\tselect b\n" +
+                        "\tfrom d\n" +
+                        ")", //
+                            SQLUtils.toSQLString(stmt, JdbcConstants.DB2, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION));
+    }
+}