add method PageUtils.hasUnorderedLimit for mysql. for issue #1688

src/test/java/com/alibaba/druid/bvt/sql/PagerUtilsTest_hasUnorderedLimit.java

@@ -0,0 +1,24 @@
+package com.alibaba.druid.bvt.sql;
+
+import com.alibaba.druid.sql.PagerUtils;
+import com.alibaba.druid.util.JdbcConstants;
+import junit.framework.TestCase;
+import org.junit.Assert;
+
+public class PagerUtilsTest_hasUnorderedLimit extends TestCase {
+
+    public void test_false() throws Exception {
+        String sql = " select * from test t order by id limit 3";
+        assertFalse(PagerUtils.hasUnorderedLimit(sql, JdbcConstants.MYSQL));
+    }
+
+    public void test_false_1() throws Exception {
+        String sql = " select * from test t";
+        assertFalse(PagerUtils.hasUnorderedLimit(sql, JdbcConstants.MYSQL));
+    }
+
+    public void test_true() throws Exception {
+        String sql = " select * from test t limit 3";
+        assertTrue(PagerUtils.hasUnorderedLimit(sql, JdbcConstants.MYSQL));
+    }
+}