Seata入门系列【9】Seata之SQL语句限制

布满荆棘的人生 2024-02-21 09:45 13阅读 0赞

## 1 前言 ##

以下内容摘自官网(地址:[http://seata.io/zh-cn/docs/user/sqlreference/sql-restrictions.html][http_seata.io_zh-cn_docs_user_sqlreference_sql-restrictions.html])

在使用Seata 的时候，对SQL语句还是有很多限制，所以在使用的时候需要格外注意这个问题（较新版本可能已支持）

## 2 SQL限制 ##

Seata 事务目前支持 INSERT、UPDATE、DELETE 三类 DML 语法的部分功能，这些类型都是已经经过Seata开源社区的验证。SQL 的支持范围还在不断扩大，建议在本文限制的范围内使用。如果您有意帮助社区支持更多类型的SQL，请提交PR申请。

### 2.1 使用限制 ###

*  不支持 SQL 嵌套
 *  不支持多表复杂 SQL(自1.6.0版本，MySQL支持UPDATE JOIN语句)
 *  不支持存储过程、触发器
 *  部分数据库不支持批量更新，在使用 MySQL、Mariadb、PostgreSQL9.6+作为数据库时支持批量，批量更新方式如下以 Java 为例

// use JdbcTemplate
        public void batchUpdate() {
        
            jdbcTemplate.batchUpdate(
                "update storage_tbl set count = count -1 where id = 1",
                "update storage_tbl set count = count -1 where id = 2"
    		);
        }
    
        // use Statement
        public void batchUpdateTwo() {
        
            statement.addBatch("update storage_tbl set count = count -1 where id = 1");
            statement.addBatch("update storage_tbl set count = count -1 where id = 2");
            statement.executeBatch();
        }

### 2.2 DML语句 ###

主要介绍 DML 语句类型、SQL 实例以及 Seata 是否支持

<table> 
 <thead> 
  <tr> 
   <th>类型</th> 
   <th>SQL 实例</th> 
   <th>是否支持</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>INSERT</td> 
   <td>INSERT INTO tb1_name (col_name,…) VALUES ({expr | FAULT},…),(…),…或 INSERT INTO tb1_name SET col_name={expr | DEFAULT}, … 或INSERT INTO tb1_name (col_name,…) VALUES ({expr | FAULT},…) ON DUPLICATE KEY UPDATE field1=value1,…;</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>UPDATE</td> 
   <td>UPDATE tb1_name SET col_name1=expr1 [, col_name2=expr2 …][WHERE where_definition]</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DELETE</td> 
   <td>DELETE FROM tb1_name [WHERE where_definition]</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SELECT</td> 
   <td>SELECT [ALL | DISTINCT | DISTINCTROW ]select_expr, … FROM tb1_name[WHERE where_definition]</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>REPLACE</td> 
   <td>REPLACE [LOW_PRIORITY | DELAYED][INTO] tb1_name [(col_name,…)]VALUES ({expr | DEFAULT},…),(…),…或REPLACE [LOW_PRIORITY | DELAYED][INTO] tb1_nameSET col_name={expr | DEFAULT}, …</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>TRUNCATE</td> 
   <td>TRUNCATE [TABLE] tb1_name</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>UPDATE JOIN</td> 
   <td>UPDATE tb1_name tb1 JOIN tb2_name tb2 ON tb2.col_name=tb1.col_name SET tb1.col_name1=expr1 [, tb1.col_name2=expr2 …][ [WHERE where_definition]</td> 
   <td>是 since 1.6.0</td> 
  </tr> 
 </tbody> 
</table>

### 2.3 SQL修饰 ###

Seata 的隔离级别默认为读未提交，该模式下本文表中的 select 语句的 SQL 修饰用法都是支持的；使用 for update 代理可以让 Seata 达到读已提交，该模式下 select 语句的用法只能部分支持。

#### 2.3.1 DML语句支持 ####

<table> 
 <thead> 
  <tr> 
   <th>类型</th> 
   <th>SQL 实例</th> 
   <th>是否支持</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>AND &amp; OR</td> 
   <td>UPDATE … WHERE col_name1=expr1 AND col_name2= expr2</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LIKE</td> 
   <td>UPDATE … WHERE col_name1 LIKE ‘NE’</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>通配符</td> 
   <td>UPDATE … WHERE col_name1 LIKE ‘NE%’</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>BETWEEN</td> 
   <td>UPDATE … WHERE col_name1 BETWEEN expr1 AND expr2</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ON DUPLICATE</td> 
   <td>INSERT INTO tb1_name [(col_name,…)]VALUES ({expr | DEFAULT},…),(…),…[ ON DUPLICATE KEY UPDATE col_name=expr, … ]</td> 
   <td>是</td> 
  </tr> 
 </tbody> 
</table>

#### 2.3.2 Select语句支持 ####

<table> 
 <thead> 
  <tr> 
   <th>类型</th> 
   <th>SQL 实例</th> 
   <th>读未提交</th> 
   <th>读已提交</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>AND &amp; OR</td> 
   <td>SELECT * FROM tb1_name WHERE col_name1=expr1 AND col_name2= expr2</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ORDER BY</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name ORDER BY col_name1</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>GROUP BY</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name GROUP BY col_name1</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LIKE</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name WHERE col_name1 LIKE ‘NE’</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>通配符</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name WHERE col_name1 LIKE ‘NE%’</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>EXISTS</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name WHERE EXISTS (expr1)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>IN</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name WHERE col_name1 IN (expr1, expr2,…)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>BETWEEN</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name WHERE col_name1 BETWEEN expr1 AND expr2</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ON DUPLICATE</td> 
   <td>INSERT INTO tb1_name [(col_name,…)]VALUES ({expr | DEFAULT},…),(…),…[ ON DUPLICATE KEY UPDATE col_name=expr, … ]</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ALIASES</td> 
   <td>SELECT t1. col_name1, t2.col_name2 FROM tb1_name AS t1, tb2_name AS t2 WHERE t1. col_name=expr AND t2. col_name=expr</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TOP</td> 
   <td>SELECT TOP 2 * FROM tb1_name</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LIMIT</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name LIMIT 5</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>JOININNER JOINLEFT JOINRIGHT JOINFULL JOIN</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name JOIN tb2_name&gt;ON tb1_name. col_name1= tb2_name. col_name1</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>UNIONUNION ALLSELECT INTO</td> 
   <td>SELECT col_name1, col_name2 FROM tb1_name UNION SELECT col_name1, col_name2 FROM tb2_name</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
 </tbody> 
</table>

### 2.4 函数 ###

下面的表列出了 DQL 语句和 DML 语句对函数的支持情况。需要注意的是，在 DML 语句中使用函数，不能将其作为主键

#### 2.4.1 DML语句支持 ####

<table> 
 <thead> 
  <tr> 
   <th>类型</th> 
   <th>是否支持</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>CONCAT(string2[,…])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>INSTR(string,substring)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LCASE(string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LEFT(string2,length)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LENGTH(string)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LOAD_FILE(file_name)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LOCATE(substring,string[,start_position])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LPAD(string2,length,pad)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LTRIM(string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>REPEAT(string2,count)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>REPLACE(str,search_str,replace_str)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RPAD(string2,length,pad)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RTRIM(string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>STRCMP(string1,string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SUBSTRING(str,position[,length])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TRIM([[BOTH|LEADING|TRAILING][padding]FROM]string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>UCASE(string2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RIGHT(string2,length)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SPACE(count)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ABS(number2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>BIN(decimal_number)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CEILING(number2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CONV(number2,from_base,to_base)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FLOOR(number2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FORMAT(number,decimal_places)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>HEX(DecimalNumber)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LEAST(number,number2[,…])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MOD(numerator,denominator)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>POWER(number,power)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RAND([seed])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ROUND(number[,decimals])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SIGN(number2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SQRT(number2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ADDTIME(date2,time_interval)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CONVERT_TZ(datetime2,fromTZ,toTZ)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_DATE()</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_TIME()</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_TIMESTAMP()</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_ADD(date2,INTERVALd_valued_type)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_FORMAT(datetime,FormatCodes)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_SUB(date2,INTERVALd_valued_type)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATEDIFF(date1,date2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAY(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYNAME(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFWEEK(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFYEAR(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>EXTRACT(interval_nameFROMdate)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MAKEDATE(year,day)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MAKETIME(hour,minute,second)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MONTHNAME(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>NOW()</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SEC_TO_TIME(seconds)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>STR_TO_DATE(string,format)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TIMEDIFF(datetime1,datetime2)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TIME_TO_SEC(time)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>WEEK(date_time[,start_of_week])</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>YEAR(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFMONTH(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>HOUR(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LAST_DAY(date)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MICROSECOND(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MONTH(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MINUTE(datetime)</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FIRST()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>LAST()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>MIN()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>MAX()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>AVG()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>SUM()</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>COUNT()</td> 
   <td>否</td> 
  </tr> 
 </tbody> 
</table>

#### 2.4.2 DQL语句支持 ####

<table> 
 <thead> 
  <tr> 
   <th>类型</th> 
   <th>读未提交</th> 
   <th>读已提交</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>CONCAT(string2[,…])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>INSTR(string,substring)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LCASE(string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LEFT(string2,length)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LENGTH(string)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LOAD_FILE(file_name)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LOCATE(substring,string[,start_position])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LPAD(string2,length,pad)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LTRIM(string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>REPEAT(string2,count)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>REPLACE(str,search_str,replace_str)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RPAD(string2,length,pad)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RTRIM(string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>STRCMP(string1,string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SUBSTRING(str,position[,length])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TRIM([[BOTH|LEADING|TRAILING][padding]FROM]string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>UCASE(string2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RIGHT(string2,length)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SPACE(count)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ABS(number2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>BIN(decimal_number)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CEILING(number2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CONV(number2,from_base,to_base)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FLOOR(number2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FORMAT(number,decimal_places)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>HEX(DecimalNumber)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LEAST(number,number2[,…])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MOD(numerator,denominator)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>POWER(number,power)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>RAND([seed])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ROUND(number[,decimals])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SIGN(number2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SQRT(number2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>ADDTIME(date2,time_interval)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CONVERT_TZ(datetime2,fromTZ,toTZ)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_DATE()</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_TIME()</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>CURRENT_TIMESTAMP()</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_ADD(date2,INTERVALd_valued_type)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_FORMAT(datetime,FormatCodes)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATE_SUB(date2,INTERVALd_valued_type)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DATEDIFF(date1,date2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAY(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYNAME(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFWEEK(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFYEAR(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>EXTRACT(interval_nameFROMdate)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MAKEDATE(year,day)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MAKETIME(hour,minute,second)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MONTHNAME(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>NOW()</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>SEC_TO_TIME(seconds)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>STR_TO_DATE(string,format)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TIMEDIFF(datetime1,datetime2)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>TIME_TO_SEC(time)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>WEEK(date_time[,start_of_week])</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>YEAR(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>DAYOFMONTH(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>HOUR(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>LAST_DAY(date)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MICROSECOND(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MONTH(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>MINUTE(datetime)</td> 
   <td>是</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>FIRST()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>LAST()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>MIN()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>MAX()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>AVG()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>SUM()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>COUNT()</td> 
   <td>是</td> 
   <td>否</td> 
  </tr> 
 </tbody> 
</table>

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