在ORDER BY子句中,使用CASE语句根据需要的条件对别名列进行排序。例如,假设我们想按照"fname"列的长度进行排序,可以使用以下语句: 接下来,使用ORDER BY子句对别名列进行排序。在ORDER BY子句中,使用CASE语句根据需要的条件对别名列进行排序。例如,假设我们想按照"fname"列的长度进行排序,可以使用以下语句: 上述...
ORDER BY CASE constellation WHEN'白羊'THEN1WHEN'金牛'THEN2WHEN'双子'THEN3WHEN'巨蟹'THEN4WHEN'狮子'THEN5WHEN'处女'THEN6WHEN'天秤'THEN7WHEN'天蝎'THEN8WHEN'射手'THEN9WHEN'摩羯'THEN10WHEN'水瓶'THEN11WHEN'双鱼'THEN12END DESC
e.salary,CASEWHENe.salary<5000THEN'低'WHENe.salary<15000THEN'中'ELSE'高'ENDASsalary_levelFROMemployees eORDERBYCASEWHENe.salary<5000THEN3WHENe.salary<15000THEN2ELSE1END, first_name; 缩写函数 除了以上两种形式的CASE表达式之外,PostgreSQL还提供了两个与NULL相关的缩写CASE表达式(函数):NULLIF和COALEASE。
具有limit 1和order by不需要的where条件的PostgreSQL慢查询 具有特殊条件的PostgreSQL连接 具有多个案例的sql连接 VBA选择案例有多个条件 事务列表上具有多个联接条件的SQL请求(postgreSQL) 具有多个条件的条件回归 具有多个子串规则的Mysql案例 具有条件和多个排序列的Order by case语句以及else ...
order by case when publish_date >= publish_date - 7 then 1 when publish_date >= publish_date - 30 then 3 else 3 end, ts_rank(tsvector_ft,q) desc; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. RUM索引-比ES 7.x还快 ...
ORDER BY CASE WHEN proj_status = 'Tested' then 1 WHEN proj_status = 'Completed' then 2 WHEN proj_status = 'Pending' then 3 WHEN proj_status = 'TO-DO' then 4 END; In the above syntax, we have simply specified the sorting order. This query will return the custom-sorted table. The...
CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'm' THEN 'materialized view' WHEN 'i' THEN 'index' WHEN 'S' THEN 'sequence' WHEN 't' THEN 'TOAST table' WHEN 'f' THEN 'foreign table' WHEN 'p' THEN 'partitioned table' ...
order by "Average Salary" DESC; 1. 2. 3. 4. 补充: Union(union all): 指令的目的是将两个 SQL 语句的结果集合并起来,得到你所需要的查询结果。 Union:对两个结果集进行并集操作,不包括重复行,同时进行默认规则的排序; Union All:对两个结果集进行并集操作,包括重复行,不进行排序; ...
distinctfromw.classidandr.objidisnotdistinctfromw.objidandr.objsubidisnotdistinctfromw.objsubidandr.transactionidisnotdistinctfromw.transactionidandr.pid <> w.pidorderby((casew.modewhen'INVALID'then0when'AccessShareLock'then1when'RowShareLock'then2when'RowExclusiveLock'then3when'ShareUpdateExclusive...
SELECT n.nspname as"Schema",c.relname as"Name",CASE c.relkind WHEN'r'THEN'table'WHEN'v'THEN'view'WHEN'm'THEN'materialized view'WHEN'i'THEN'index'WHEN'S'THEN'sequence'WHEN't'THEN'TOAST table'WHEN'f'THEN'foreign table'WHEN'p'THEN'partitioned table'WHEN'I'THEN'partitioned index'END ...