PageUtils support SQL Server

src/main/java/com/alibaba/druid/sql/PagerUtils.java

@@ -192,10 +192,8 @@ public class PagerUtils {
 
             SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
             SQLOrderBy orderBy = select.getOrderBy();
-            if (orderBy != null) {
-                aggregateExpr.setOver(new SQLOver(orderBy));
-                select.setOrderBy(null);
-            }
+            aggregateExpr.setOver(new SQLOver(orderBy));
+            select.setOrderBy(null);
 
             queryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
 
@@ -208,21 +206,24 @@ public class PagerUtils {
 
             return SQLUtils.toSQLString(countQueryBlock, dbType);
         }
+        
 
         SQLServerSelectQueryBlock countQueryBlock = new SQLServerSelectQueryBlock();
         countQueryBlock.getSelectList().add(new SQLSelectItem(new SQLPropertyExpr(new SQLIdentifierExpr("XX"), "*")));
+
+        countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
+        
+        if (offset <= 0) {
+            countQueryBlock.setTop(new SQLServerTop(new SQLNumberExpr(count)));
+            return SQLUtils.toSQLString(countQueryBlock, dbType);
+        }
+        
         SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
         SQLOrderBy orderBy = select.getOrderBy();
         aggregateExpr.setOver(new SQLOver(orderBy));
         select.setOrderBy(null);
         countQueryBlock.getSelectList().add(new SQLSelectItem(aggregateExpr, "ROWNUM"));
 
-        countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
-
-        if (offset <= 0) {
-            return SQLUtils.toSQLString(countQueryBlock, dbType);
-        }
-
         SQLServerSelectQueryBlock offsetQueryBlock = new SQLServerSelectQueryBlock();
         offsetQueryBlock.getSelectList().add(new SQLSelectItem(new SQLAllColumnExpr()));
         offsetQueryBlock.setFrom(new SQLSubqueryTableSource(new SQLSelect(countQueryBlock), "XXX"));

src/test/java/com/alibaba/druid/bvt/sql/PagerUtilsTest_Limit_SQLServer_2.java

@@ -0,0 +1,23 @@
+package com.alibaba.druid.bvt.sql;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.PagerUtils;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class PagerUtilsTest_Limit_SQLServer_2 extends TestCase {
+
+    public void test_db2_union() throws Exception {
+        String sql = "select * from t1 union select * from t2";
+        String result = PagerUtils.limit(sql, JdbcConstants.SQL_SERVER, 0, 10);
+        Assert.assertEquals("SELECT TOP 10 XX.*" //
+                            + "\nFROM (SELECT *" //
+                            + "\n\tFROM t1" //
+                            + "\n\tUNION" //
+                            + "\n\tSELECT *" //
+                            + "\n\tFROM t2" //
+                            + "\n\t) XX", result);
+    }
+}

src/test/java/com/alibaba/druid/bvt/sql/PagerUtilsTest_Limit_SQLServer_3.java

@@ -0,0 +1,19 @@
+package com.alibaba.druid.bvt.sql;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.PagerUtils;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class PagerUtilsTest_Limit_SQLServer_3 extends TestCase {
+
+    public void test_db2_union() throws Exception {
+        String sql = "select * from t1 where id > 1";
+        String result = PagerUtils.limit(sql, JdbcConstants.SQL_SERVER, 0, 10);
+        Assert.assertEquals("SELECT TOP 10 *" //
+                            + "\nFROM t1" //
+                            + "\nWHERE id > 1", result);
+    }
+}

src/test/java/com/alibaba/druid/bvt/sql/PagerUtilsTest_Limit_SQLServer_4.java

@@ -0,0 +1,23 @@
+package com.alibaba.druid.bvt.sql;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.PagerUtils;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class PagerUtilsTest_Limit_SQLServer_4 extends TestCase {
+
+    public void test_db2_union() throws Exception {
+        String sql = "select * from t1 where id > 1";
+        String result = PagerUtils.limit(sql, JdbcConstants.SQL_SERVER, 100, 10);
+        Assert.assertEquals("SELECT *" //
+                            + "\nFROM (SELECT *, ROW_NUMBER() OVER () AS ROWNUM" //
+                            + "\n\tFROM t1" //
+                            + "\n\tWHERE id > 1" //
+                            + "\n\t) XX" //
+                            + "\nWHERE ROWNUM > 100" //
+                            + "\n\tAND ROWNUM <= 110", result);
+    }
+}