mybatis group by substr函数传参报错

报异常：

### Cause: java.sql.SQLSyntaxErrorException: ORA-00979: 不是 GROUP BY 表达式

SELECT
	SUBSTR( region_code, 1,#{ queryMap.groupCodeLength, jdbcType = INTEGER } ) AS "region_code",
	count( CASE WHEN TYPE = 1 THEN 0 END ) AS "like",
	count( CASE WHEN TYPE = 2 THEN 0 END ) AS "roast" 
FROM
	t_pub_sentiment 
WHERE
	1 = 1 
GROUP BY
	SUBSTR(region_code,1,#{ queryMap.groupCodeLength,jdbcType = INTEGER })

更改后：

SELECT
	SUBSTR( region_code, 1, $ { queryMap.groupCodeLength } ) AS "region_code",
	count( CASE WHEN TYPE = 1 THEN 0 END ) AS "like",
	count( CASE WHEN TYPE = 2 THEN 0 END ) AS "roast" 
FROM
	t_pub_sentiment 
WHERE
	1 = 1 
GROUP BY
	SUBSTR( region_code, 1, $ { queryMap.groupCodeLength } )

原因：#{} 和 ${} 在预编译中的处理是不一样的。#{} 在预处理时，会把参数部分用一个占位符 ? 代替。而 ${} 则只是简单的字符串替换。 ${}有sql注入的风险，需谨慎使用。