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docs/MatrixOne/Reference/Variable/system-variables/keep_user_target_list_in_result.md

@@ -0,0 +1,66 @@
+# keep_user_target_list_in_result 保持查询结果集列名与用户指定大小写一致
+
+在 MatrixOne 查询中，保持结果集列名与用户指定的名称大小一致，除了可以通过使用别名（alias）来实现，还可以通过设置参数来实现。
+
+`keep_user_target_list_in_result` 是 MatrixOne 设置查询结果集列名与用户指定的名称大小写是否一致的一个参数。
+
+## 配置
+
+在命令行执行以下语句：
+
+```sql
+set global keep_user_target_list_in_result = 1;// 默认为 0，重新连接数据库生效
+```
+
+## 示例
+
+```sql
+create table t1(aa int, bb int, cc int, AbC varchar(25), A_BC_d double);
+insert into t1 values (1,2,3,'A',10.9);
+
+mysql> select * from t1; 
++------+------+------+------+--------+
+| aa   | bb   | cc   | abc  | a_bc_d |
++------+------+------+------+--------+
+|    1 |    2 |    3 | A    |   10.9 |
++------+------+------+------+--------+
+1 row in set (0.00 sec)
+
+mysql> select @@keep_user_target_list_in_result;--查询参数值，默认关闭
++-----------------------------------+
+| @@keep_user_target_list_in_result |
++-----------------------------------+
+| 0                                 |
++-----------------------------------+
+1 row in set (0.01 sec)
+
+mysql> select aA, bB, CC, abc, a_Bc_D from t1;--在设置关闭情况下，查询结果集列名与用户指定的名称大小写不一致
++------+------+------+------+--------+
+| aa   | bb   | cc   | abc  | a_bc_d |
++------+------+------+------+--------+
+|    1 |    2 |    3 | A    |   10.9 |
++------+------+------+------+--------+
+1 row in set (0.00 sec)
+
+mysql> set global keep_user_target_list_in_result =1;--开启查询结果集列名与用户指定的名称大小一致设置
+Query OK, 0 rows affected (0.01 sec)
+
+mysql> exit;--退出数据库重新连接后参数生效
+
+mysql> select @@keep_user_target_list_in_result;--查询参数值，开启成功
++-----------------------------------+
+| @@keep_user_target_list_in_result |
++-----------------------------------+
+| 1                                 |
++-----------------------------------+
+1 row in set (0.00 sec)
+
+mysql> select aA, bB, CC, abc, a_Bc_D from t1;--在设置开启情况下，查询结果集列名与用户指定的名称大小写一致
++------+------+------+------+--------+
+| aA   | bB   | CC   | abc  | a_Bc_D |
++------+------+------+------+--------+
+|    1 |    2 |    3 | A    |   10.9 |
++------+------+------+------+--------+
+1 row in set (0.00 sec)
+
+```

mkdocs.yml

@@ -247,6 +247,7 @@ nav:
           - 保存查询结果支持: MatrixOne/Reference/Variable/system-variables/save_query_result.md
           - 时区支持: MatrixOne/Reference/Variable/system-variables/timezone.md
           - 大小写敏感支持: MatrixOne/Reference/Variable/system-variables/lower_case_tables_name.md
+          - 查询结果集列名与用户指定大小写一致支持: MatrixOne/Reference/Variable/system-variables/keep_user_target_list_in_result.md
         - 自定义变量: MatrixOne/Reference/Variable/custom-variable.md
       - SQL 结构与语法:
         - 关键字: MatrixOne/Reference/Language-Structure/keywords.md