From 4a273c6fe4a2e4b4e16f513c374da6fca9ac09ba Mon Sep 17 00:00:00 2001
From: wenshao <wenshao@wenshaos-MacBook-Pro.local>
Date: Sat, 19 Nov 2016 23:32:46 +0800
Subject: [PATCH] improved sql parser parameterized sharding support. issue
 #1488

---
 .../mysql/visitor/MySqlOutputVisitor.java     | 18 ++++++++++++------
 ...ySqlParameterizedOutputVisitorTest_13.java | 19 +++++++++++++++++++
 2 files changed, 31 insertions(+), 6 deletions(-)
 create mode 100644 src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlParameterizedOutputVisitorTest_13.java

diff --git a/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java b/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
index 1701b9016c..66ebbbbf03 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
@@ -199,17 +199,22 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
         }
 
         final String name = x.getName();
-        boolean computeSharding = isShardingSupport();
-        if (computeSharding) {
+        if (shardingSupport) {
             SQLObject parent = x.getParent();
-            computeSharding = parent instanceof SQLExprTableSource || parent instanceof SQLPropertyExpr;
+            shardingSupport = parent instanceof SQLExprTableSource || parent instanceof SQLPropertyExpr;
         }
 
-        if (computeSharding) {
+        if (shardingSupport) {
             int pos = name.lastIndexOf('_');
             if (pos != -1 && pos != name.length() - 1) {
+                boolean quote = name.charAt(0) == '`' && name.charAt(name.length() - 1) == '`';
                 boolean isNumber = true;
-                for (int i = pos + 1; i < name.length(); ++i) {
+
+                int end = name.length();
+                if (quote) {
+                    end--;
+                }
+                for (int i = pos + 1; i < end; ++i) {
                     char ch = name.charAt(i);
                     if (ch < '0' || ch > '9') {
                         isNumber = false;
@@ -217,7 +222,8 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
                     }
                 }
                 if (isNumber) {
-                    String realName = name.substring(0, pos);
+                    int start = quote ? 1 : 0;
+                    String realName = name.substring(start, pos);
                     print0(realName);
                     incrementReplaceCunt();
                     return false;
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlParameterizedOutputVisitorTest_13.java b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlParameterizedOutputVisitorTest_13.java
new file mode 100644
index 0000000000..da4a2e3fbb
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlParameterizedOutputVisitorTest_13.java
@@ -0,0 +1,19 @@
+package com.alibaba.druid.bvt.sql.mysql;
+
+import com.alibaba.druid.sql.visitor.ParameterizedOutputVisitorUtils;
+import com.alibaba.druid.util.JdbcConstants;
+import junit.framework.TestCase;
+
+/**
+ * Created by wenshao on 16/8/23.
+ */
+public class MySqlParameterizedOutputVisitorTest_13 extends TestCase {
+    public void test_for_parameterize() throws Exception {
+        final String dbType = JdbcConstants.MYSQL;
+
+        String sql = "select * from `user_0000` `user`";
+        String psql = ParameterizedOutputVisitorUtils.parameterize(sql, dbType);
+        assertEquals("SELECT *\n" +
+                "FROM user `user`", psql);
+    }
+}