From c5b1522a8c0b3f6a540ce5a823723cbac390ab7f Mon Sep 17 00:00:00 2001
From: wenshao <szujobs@hotmail.com>
Date: Tue, 2 Jun 2015 08:52:53 +0800
Subject: [PATCH] improved postgresql support

---
 .../parser/PGSQLStatementParser.java          |  4 +-
 .../druid/sql/parser/SQLStatementParser.java  |  3 ++
 .../bvt/sql/postgresql/PGAlterTableTest1.java | 54 +++++++++++++++++++
 3 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGAlterTableTest1.java

diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSQLStatementParser.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSQLStatementParser.java
index 69207d1621..3dae6d5a00 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSQLStatementParser.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/parser/PGSQLStatementParser.java
@@ -299,7 +299,9 @@ public class PGSQLStatementParser extends SQLStatementParser {
     }
 
     protected SQLAlterTableAlterColumn parseAlterColumn() {
-        accept(Token.COLUMN);
+        if (lexer.token() == Token.COLUMN) {
+            lexer.nextToken();
+        }
 
         SQLColumnDefinition column = this.exprParser.parseColumn();
 
diff --git a/src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java b/src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java
index 7c3cf72a8f..3ee333c718 100644
--- a/src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java
+++ b/src/main/java/com/alibaba/druid/sql/parser/SQLStatementParser.java
@@ -796,6 +796,9 @@ public class SQLStatementParser extends SQLParser {
                     if (lexer.token() == Token.COLUMN) {
                         SQLAlterTableAlterColumn alterColumn = parseAlterColumn();
                         stmt.getItems().add(alterColumn);
+                    } else if (lexer.token() == Token.LITERAL_ALIAS) {
+                        SQLAlterTableAlterColumn alterColumn = parseAlterColumn();
+                        stmt.getItems().add(alterColumn);
                     } else {
                         throw new ParserException("TODO " + lexer.token() + " " + lexer.stringVal());
                     }
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGAlterTableTest1.java b/src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGAlterTableTest1.java
new file mode 100644
index 0000000000..7085b2804c
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/postgresql/PGAlterTableTest1.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright 1999-2011 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.postgresql;
+
+import java.util.List;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.PGTest;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.postgresql.parser.PGSQLStatementParser;
+import com.alibaba.druid.sql.dialect.postgresql.visitor.PGSchemaStatVisitor;
+import com.alibaba.druid.stat.TableStat;
+
+public class PGAlterTableTest1 extends PGTest {
+
+    public void test_0() throws Exception {
+        String sql = "ALTER TABLE \"measure_data\" ALTER \"measure_id\" DROP NOT NULL";
+
+        PGSQLStatementParser parser = new PGSQLStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLStatement statemen = statementList.get(0);
+        print(statementList);
+
+        Assert.assertEquals(1, statementList.size());
+
+        PGSchemaStatVisitor visitor = new PGSchemaStatVisitor();
+        statemen.accept(visitor);
+
+        System.out.println("Tables : " + visitor.getTables());
+        System.out.println("fields : " + visitor.getColumns());
+
+        Assert.assertTrue(visitor.getTables().containsKey(new TableStat.Name("measure_data")));
+        
+        Assert.assertTrue(visitor.getTables().get(new TableStat.Name("measure_data")).getAlterCount() == 1);
+
+        Assert.assertTrue(visitor.getColumns().size() == 1);
+    }
+
+   
+}