SQL 语句优化：获取符合条件的数量

这是我的 SQL 语句 "SELECT DISTINCT\nscenaTypeAss.\nFROM\n(\nSELECT\nf.LINK_CODE AS file,\na.TYPE_NAME AS "typeName",\na.TREE_SORT AS "treeSort",\na.TREE_SORTS AS "treeSorts",\na.TREE_LEVEL AS "treeLevel",\na.TREE_LEAF AS "treeLeaf",\na.PARENT_ID AS "parentId",\na.PARENT_IDS AS "parentIds",\na.PARENT_NAMES AS "parentNames",\na.create_user AS "createUser",\na.update_user AS "updateUser",\na.remark AS "remark",\na.id AS "id",\na.create_by AS "createBy",\na.create_dept AS "createDept",\na.create_time AS "createTime",\na.update_by AS "updateBy",\na.update_time AS "updateTime",\na.update_ip AS "updateIp",\na.version AS "version",\na.del_flag AS "delFlag"\nFROM\nlts_scena_type_new a\nLEFT JOIN sys_user t ON FIND_IN_SET( t.id, a.create_by )\nLEFT JOIN sys_dept d ON t.dept_id = d.id\nLEFT JOIN lts_file_info f ON f.LINK_CODE = a.id \n) scenaTypeAss\nORDER BY\nscenaTypeAss.typeName ASC" 我想将其中的 f.LINK_CODE AS file 换成获取符合的数量内容：你可以使用 COUNT 函数来获取符合条件的数量，并将其命名为 "file_count"。修改后的 SQL 语句如下：\n\nSELECT DISTINCT\nscenaTypeAss.,\nCOUNT(f.LINK_CODE) AS file_count\nFROM\n(\nSELECT\nCOUNT(f.LINK_CODE) AS file_count,\na.TYPE_NAME AS "typeName",\na.TREE_SORT AS "treeSort",\na.TREE_SORTS AS "treeSorts",\na.TREE_LEVEL AS "treeLevel",\na.TREE_LEAF AS "treeLeaf",\na.PARENT_ID AS "parentId",\na.PARENT_IDS AS "parentIds",\na.PARENT_NAMES AS "parentNames",\na.create_user AS "createUser",\na.update_user AS "updateUser",\na.remark AS "remark",\na.id AS "id",\na.create_by AS "createBy",\na.create_dept AS "createDept",\na.create_time AS "createTime",\na.update_by AS "updateBy",\na.update_time AS "updateTime",\na.update_ip AS "updateIp",\na.version AS "version",\na.del_flag AS "delFlag"\nFROM\nlts_scena_type_new a\nLEFT JOIN sys_user t ON FIND_IN_SET( t.id, a.create_by )\nLEFT JOIN sys_dept d ON t.dept_id = d.id\nLEFT JOIN lts_file_info f ON f.LINK_CODE = a.id \n) scenaTypeAss\nGROUP BY\nscenaTypeAss.typeName\nORDER BY\nscenaTypeAss.typeName ASC