improved sql parser for mysql, issue #2984

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

@@ -628,6 +628,8 @@ public class SQLExprParser extends SQLParser {
                         lexer.nextToken();
                         break;
                     case IDENTIFIER: // 当负号后面为字段的情况
+                    case LITERAL_CHARS:
+                    case LITERAL_ALIAS:
                         sqlExpr = new SQLIdentifierExpr(lexer.stringVal());
                         lexer.nextToken();
 
@@ -670,6 +672,8 @@ public class SQLExprParser extends SQLParser {
                         lexer.nextToken();
                         break;
                     case IDENTIFIER: // 当+号后面为字段的情况
+                    case LITERAL_CHARS:
+                    case LITERAL_ALIAS:
                         sqlExpr = new SQLIdentifierExpr(lexer.stringVal());
                         sqlExpr = new SQLUnaryExpr(SQLUnaryOperator.Plus, sqlExpr);
                         lexer.nextToken();

src/test/java/com/alibaba/druid/bvt/sql/mysql/select/MySqlSelectTest_229_interval.java

@@ -0,0 +1,65 @@
+/*
+ * 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.mysql.select;
+
+import com.alibaba.druid.sql.MysqlTest;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitorAdapter;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+import java.util.List;
+
+
+public class MySqlSelectTest_229_interval extends MysqlTest {
+
+    public void test_0() throws Exception {
+        String sql = "select DATE_ADD(utc_date(), INTERVAL -'5' DAY)";
+
+//        System.out.println(sql);
+
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+
+        assertEquals(1, statementList.size());
+
+        SQLStatement stmt = statementList.get(0);
+
+
+        assertEquals("SELECT DATE_ADD(utc_date(), INTERVAL -5 DAY)", stmt.toString());
+
+        assertEquals("select DATE_ADD(utc_date(), interval -5 day)", stmt.clone().toLowerCaseString());
+    }
+
+    public void test_1() throws Exception {
+        String sql = "select DATE_ADD(utc_date(), INTERVAL +'5' DAY)";
+
+//        System.out.println(sql);
+
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+
+        assertEquals(1, statementList.size());
+
+        SQLStatement stmt = statementList.get(0);
+
+
+        assertEquals("SELECT DATE_ADD(utc_date(), INTERVAL +5 DAY)", stmt.toString());
+
+        assertEquals("select DATE_ADD(utc_date(), interval +5 day)", stmt.clone().toLowerCaseString());
+    }
+}