add sql parser testcases

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

@@ -16,6 +16,27 @@
 package com.alibaba.druid.sql.ast.statement;
 
 public enum SQLObjectType {
-    TABLE, FUNCTION, PROCEDURE, USER, DATABASE, //
-    ROLE, PROJECT, PACKAGE, RESOURCE, INSTANCE, JOB, VOLUME, OfflineModel, XFLOW // for odps
+    TABLE("TABLE"), // 
+    FUNCTION("FUNCTION"), // 
+    PROCEDURE("PROCEDURE"), // 
+    USER("USER"), //
+    DATABASE("DATABASE"), //
+    ROLE("ROLE"), // 
+    PROJECT("PROJECT"), // 
+    PACKAGE("PACKAGE"), // 
+    RESOURCE("RESOURCE"), // 
+    INSTANCE("INSTANCE"), // 
+    JOB("JOB"), // 
+    VOLUME("VOLUME"), // 
+    OfflineModel("OFFLINEMODEL"), // 
+    XFLOW("XFLOW") // for odps
+    ;
+    
+    public final String name;
+    public final String name_lcase;
+    
+    SQLObjectType(String name) {
+        this.name = name;
+        this.name_lcase = name.toLowerCase();
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/MysqlForeignKey.java

@@ -98,23 +98,44 @@ public class MysqlForeignKey extends SQLForeignKeyImpl {
 
         RESTRICT("RESTRICT"), CASCADE("CASCADE"), SET_NULL("SET NULL"), NO_ACTION("NO ACTION");
 
-        private String text;
+        public final String name;
+        public final String name_lcase;
 
-        Option(String text){
-            this.text = text;
+        Option(String name){
+            this.name = name;
+            this.name_lcase = name.toLowerCase();
         }
 
         public String getText() {
-            return text;
+            return name;
         }
 
     }
 
     public static enum Match {
-        FULL, PARTIAL, SIMPLE;
+        FULL("FULL"), 
+        PARTIAL("PARTIAL"), 
+        SIMPLE("SIMPLE");
+        
+        public final String name;
+        public final String name_lcase;
+        
+        Match(String name) {
+            this.name = name;
+            this.name_lcase = name.toLowerCase();
+        }
     }
 
     public static enum On {
-        DELETE, UPDATE;
+        DELETE("DELETE"), // 
+        UPDATE("UPDATE");
+        
+        public final String name;
+        public final String name_lcase;
+        
+        On(String name) {
+            this.name = name;
+            this.name_lcase = name.toLowerCase();
+        }
     }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -54,6 +54,7 @@ import com.alibaba.druid.sql.dialect.mysql.ast.MySqlPrimaryKey;
 import com.alibaba.druid.sql.dialect.mysql.ast.MySqlUnique;
 import com.alibaba.druid.sql.dialect.mysql.ast.MySqlUseIndexHint;
 import com.alibaba.druid.sql.dialect.mysql.ast.MysqlForeignKey;
+import com.alibaba.druid.sql.dialect.mysql.ast.MysqlForeignKey.Option;
 import com.alibaba.druid.sql.dialect.mysql.ast.clause.MySqlCaseStatement;
 import com.alibaba.druid.sql.dialect.mysql.ast.clause.MySqlCaseStatement.MySqlWhenStatement;
 import com.alibaba.druid.sql.dialect.mysql.ast.clause.MySqlCursorDeclareStatement;
@@ -605,7 +606,6 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
 
         if (x.getIndexType() != null) {
             print0(ucase ? " USING " : " using ");
-            ;
             print0(x.getIndexType());
         }
 
@@ -2810,17 +2810,20 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
         printAndAccept(x.getReferencedColumns(), ", ");
         print(')');
 
-        if (x.getReferenceMatch() != null) {
+        MysqlForeignKey.Match match = x.getReferenceMatch();
+        if (match != null) {
             print0(ucase ? " MATCH " : " match ");
-            print0(x.getReferenceMatch().name());
+            print0(ucase ? match.name : match.name_lcase);
         }
 
-        if (x.getReferenceOn() != null) {
+        MysqlForeignKey.On on = x.getReferenceOn();
+        if (on != null) {
             print0(ucase ? " ON " : " on ");
-            print0(x.getReferenceOn().name());
+            print0(ucase ? on.name : on.name_lcase);
             print(' ');
-            if (x.getReferenceOption() != null) {
-                print0(x.getReferenceOption().getText());
+            Option option = x.getReferenceOption();
+            if (option != null) {
+                print0(ucase ? option.name : option.name_lcase);
             }
         }
         return false;

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

@@ -2055,8 +2055,9 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Printab
         if (x.getOn() != null) {
             print0(ucase ? " ON " : " on ");
 
-            if (x.getObjectType() != null) {
-                print0(x.getObjectType().name());
+            SQLObjectType objectType = x.getObjectType();
+            if (objectType != null) {
+                print0(ucase ? objectType.name : objectType.name_lcase);
                 print(' ');
             }