to_char round

to_char是Oracle数据库中的一个函数，用于将数值、日期等数据类型转换为字符类型。它的语法为：to_char(参数,格式)，其中参数可以是数值、日期等数据类型，格式是一个字符串，用于指定转换后的字符类型的格式。例如，to_char(1234.56,'FM9999.99')将返回字符串'1234.56'。

round也是Oracle数据库中的一个函数，用于对数值进行四舍五入。它的语法为：round(参数,小数位数)，其中参数是需要进行四舍五入的数值，小数位数是需要保留的小数位数。例如，round(1234.567,2)将返回1234.57。

相关问题

SELECT A.XFH0101, A.XFH0103, DECODE(A.XFH0104,0,'0.00',(TO_CHAR(ROUND(A.XFH0104,2),'FM99999999999999.00'))) AS XFH0104, A.XFH0109,TO_CHAR(A.XFH0112,'YYYY-MM-DD HH:MI:SS') AS XFH0112, A.CZZX1001,B.BAAX0102,C.BACX0501,TO_CHAR(A.XFH0114,'YYYY-MM-DD') AS XFH0114, XFH0120,XFH0121, DECODE( D.XFH0302, 0, '0.00', ( TO_CHAR ( ROUND( D.XFH0302, 2 ), 'fm999999990D00' ) ) ) AS XFH0302, D.XFH0304, E.XFF0103, DECODE( D.XFH0302 * D.XFH0304,0, '0.00', (TO_CHAR(ROUND( D.XFH0302 * D.XFH0304, 2 ), 'fm999999990D00' ))) AS SUM FROM XFH01 A LEFT JOIN BAA01 B ON A.CZZX1001 = B.BAAX0101 LEFT JOIN BAC05 C ON A.SYSCODE = C.SYSCODE JOIN XFH03 D ON A.XFH0101 = D.XFH0101 JOIN XFF01 E ON D.XFF0101 = E.XFF0101 WHERE A.XFH0101 in (${xfh0101})

这是一个SQL查询语句，用于从多个表中检索数据。它使用了多个表之间的连接和条件筛选。查询的结果将返回一些列，包括XFH0101、XFH0103、XFH0104、XFH0109、XFH0112、CZZX1001、BAAX0102、BACX0501、XFH0114、XFH0120、XFH0121、XFH0302、XFH0304、XFF0103和SUM。

其中XFH01表与BAA01表和BAC05表进行了左连接，XFH01表与XFH03表和XFF01表进行了内连接。查询的条件是XFH0101在给定的xfh0101参数中。

请注意，我只能解释查询的含义和结构，无法直接执行查询或提供实际的查询结果。

帮我优化postgresql语句，如下：select source_name as "SOURCE_NAME",type_name as "TYPE_NAME",shift_date as "SHIFT_DATE",dd as "DD",task_title as "TASK_TITLE", task_content as "TASK_CONTENT",task_creator as "TASK_CREATOR",task_executor as "TASK_EXECUTOR",task_description as "TASK_DESCRIPTION", create_time as "CREATE_TIME",creatorid as "CREATORID",creatorname as "CREATORNAME",org_id as "ORG_ID",executorid as "EXECUTORID",executorname as "EXECUTORNAME", plan_start_time as "PLAN_START_TIME",plan_end_time as "PLAN_END_TIME",act_start_time as "ACT_SART_TIME",act_end_time as "ACT_END_TIME", gap_date as "GAP_DATE",task_status as "TASK_STATUS",1 as "TASK_QTY", (case when task_status='Finish' then '已结案' when task_status='Confirm'then '已结案' when gap_date>0 then '已逾期' --直播状态如下 --when gap_date>0 and gap_date<=1 then '已逾期' when gap_date>0.3 then '已结案' when gap_date<=0 and task_status='Going' then '进行中' when gap_date<=0 and task_status='Plan' then '计划中' end ) as "STATUS" -------union from ((select source_name,source_id,type_name,task_id,to_char(shift_date,'MM')||'月' as shift_date,task_title,task_content,task_status,task_creator, Plan_Start_Time,plan_end_time,act_start_time,(case when act_end_time is null then current_date else act_end_time end) as act_end_time, create_time,SUBSTR(TASK_EXECUTOR,1,8)AS TASK_EXECUTOR,'M'||TO_CHAR(SHIFT_DATE,'MM') as dd, round(date_part('epoch', (case when act_end_time is null then now() else act_end_time end) - plan_end_time))/60/60/24 as gap_date, TASK_DESCRIPTION from estone.r_est_task WHERE SITE = 'S01' --and to_char(shift_date,'yyyy')=to_char(current_date,'yyyy') --and extract(month from shift_date)>extract(month from current_date)-3 and shift_Date>to_date('20221031','yyyymmdd') ) union (select source_name,source_id,type_name,task_id,to_char(shift_date,'MM')||'月' as shift_date,task_title,task_content,task_status,task_creator, Plan_Start_Time,plan_end_time,act_start_time,(case when act_end_time is null then current_date else act_end_time end) as act_end_time, create_time,SUBSTR(TASK_EXECUTOR,1,8)AS TASK_EXECUTOR,'M'||TO_CHAR(SHIFT_DATE,'MM') as dd, round(date_part('epoch', (case when act_end_time is null then now() else act_end_time end) - create_time))/60/60/24 as gap_date, TASK_DESCRIPTION from estone.h_Est_Comp WHERE SITE = 'S01' and substr(pt_mfg_date,1,6)>=to_char(current_date-100,'yyyymm') --and to_number(substr(pt_mfg_date,5,2),'99G999D')>=extract(month from current_date)-3 --and to_char(shift_date,'yyyy')=to_char(current_date,'yyyy') --and extract(month from shift_date)>extract(month from current_date)-3 and shift_Date>to_date('20221031','yyyymmdd') ) )xx left join (select emp_no as CreatorID,emp_name as CreatorName from restricted.ausref_emp_data_ausz where substr(org_id,1,4)='MS01')yy on xx.task_creator = yy.CreatorID left join (select emp_no as ExecutorId,emp_name as ExecutorName,org_id from restricted.ausref_emp_data_ausz where substr(org_id,1,4)='MS01' )aa on xx.task_executor = aa.ExecutorId

可以尝试以下优化：

1. 将 SELECT 语句中的多个子查询转换为 JOIN，这样可以减少子查询的次数，提高查询效率。

2. 对于 WHERE 子句中的一些判断条件，可以根据具体情况添加索引，加快查询速度。

3. 对于计算字段 "STATUS" 中的逻辑判断，可以使用 CASE WHEN THEN ELSE END 语句，这样可以使查询更加简洁明了。

下面是优化后的 SQL 语句：

SELECT
source_name AS "SOURCE_NAME",
type_name AS "TYPE_NAME",
shift_date AS "SHIFT_DATE",
dd AS "DD",
task_title AS "TASK_TITLE",
task_content AS "TASK_CONTENT",
task_creator AS "TASK_CREATOR",
task_executor AS "TASK_EXECUTOR",
task_description AS "TASK_DESCRIPTION",
create_time AS "CREATE_TIME",
creatorid AS "CREATORID",
creatorname AS "CREATORNAME",
org_id AS "ORG_ID",
executorid AS "EXECUTORID",
executorname AS "EXECUTORNAME",
plan_start_time AS "PLAN_START_TIME",
plan_end_time AS "PLAN_END_TIME",
act_start_time AS "ACT_SART_TIME",
act_end_time AS "ACT_END_TIME",
gap_date AS "GAP_DATE",
task_status AS "TASK_STATUS",
1 AS "TASK_QTY",
CASE
WHEN task_status IN ('Finish', 'Confirm') THEN '已结案'
WHEN gap_date > 0.3 THEN '已结案'
WHEN gap_date > 0 THEN '已逾期'
WHEN gap_date <= 0 AND task_status = 'Going' THEN '进行中'
WHEN gap_date <= 0 AND task_status = 'Plan' THEN '计划中'
ELSE NULL
END AS "STATUS"
FROM (
SELECT
source_name,
source_id,
type_name,
task_id,
to_char(shift_date, 'MM') || '月' AS shift_date,
task_title,
task_content,
task_status,
task_creator,
Plan_Start_Time,
plan_end_time,
act_start_time,
(CASE WHEN act_end_time IS NULL THEN current_date ELSE act_end_time END) AS act_end_time,
create_time,
SUBSTR(TASK_EXECUTOR, 1, 8) AS TASK_EXECUTOR,
'M' || TO_CHAR(SHIFT_DATE, 'MM') AS dd,
ROUND(DATE_PART('epoch', (CASE WHEN act_end_time IS NULL THEN now() ELSE act_end_time END) - plan_end_time)) / 60 / 60 / 24 AS gap_date,
TASK_DESCRIPTION
FROM estone.r_est_task t
JOIN restricted.ausref_emp_data_ausz c ON t.task_creator = c.emp_no
JOIN restricted.ausref_emp_data_ausz e ON t.task_executor = e.emp_no
WHERE
t.SITE = 'S01'
AND substr(c.org_id, 1, 4) = 'MS01'
AND substr(e.org_id, 1, 4) = 'MS01'
AND t.shift_date > to_date('20221031', 'yyyymmdd')
AND t.shift_date >= current_date - interval '3 month'
) UNION (
SELECT
source_name,
source_id,
type_name,
task_id,
to_char(shift_date, 'MM') || '月' AS shift_date,
task_title,
task_content,
task_status,
task_creator,
Plan_Start_Time,
plan_end_time,
act_start_time,
(CASE WHEN act_end_time IS NULL THEN current_date ELSE act_end_time END) AS act_end_time,
create_time,
SUBSTR(TASK_EXECUTOR, 1, 8) AS TASK_EXECUTOR,
'M' || TO_CHAR(SHIFT_DATE, 'MM') AS dd,
ROUND(DATE_PART('epoch', (CASE WHEN act_end_time IS NULL THEN now() ELSE act_end_time END) - create_time)) / 60 / 60 / 24 AS gap_date,
TASK_DESCRIPTION
FROM estone.h_Est_Comp c
JOIN restricted.ausref_emp_data_ausz e ON c.task_executor = e.emp_no
WHERE
c.SITE = 'S01'
AND substr(e.org_id, 1, 4) = 'MS01'
AND substr(c.pt_mfg_date, 1, 6) >= to_char(current_date - interval '100 day', 'yyyymm')
AND c.shift_date > to_date('20221031', 'yyyymmdd')
) AS xx
LEFT JOIN restricted.ausref_emp_data_ausz AS yy ON xx.task_creator = yy.emp_no
LEFT JOIN restricted.ausref_emp_data_ausz AS aa ON xx.task_executor = aa.emp_no