public static void updateData(Connection con, String make, String reg) {
String selectString = "UPDATE Cars SET Make = ? WHERE Reg = ?";
try
{
PreparedStatement pStmt = con.prepareStatement(selectString);
pStmt.setString(1, make);
pStmt.setString(2, reg);
pStmt.executeUpdate(selectString);
pStmt.close();
}...
我为这段代码收到以下错误:
SQL Exception: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '? WHERE Reg = ?' at line 1
如果有人可以帮助我,我将不胜感激.我搜索过,但我的问题与我发现的解决方案完全不同.
我有一个包含 33 列的表，其中有多个重复项，因此我试图以这种方式删除所有重复项，因为此选择不同的查询具有正确的数据数量。
CREATE TABLE students (
school char(2),sex char(1),age int,address char(1),famsize char(3),
Pstatus char(1),Medu int,Fedu int,Mjob varchar,Fjob varchar,reason varchar,
guardian varchar,traveltime int,studytime int,failures char(1),
schoolsup varchar,famsup varchar,paid varchar,activities varchar,
nursery varchar,higher varchar,internet varchar,romantic varchar,
famrel int,freetime int,goout int,Dalc int,Walc int,
health int,absences int,id serial primary key)
我想将这个包含 8 列的 select 不同查询中的所有值插入到另一个空表中。
SELECT DISTINCT ("school","sex","age","address","famsize","Pstatus","Medu","Fedu","Mjob","Fjob","reason","nursery","internet")
FROM students;
我在MS Server Management studio v11.02上运行以下但是'我收到一个错误说:
The multi-part identifier "PO.LastPo" could not be bound.
我能做些什么来解决这个问题？
SELECT DISTINCT PO.LastPo
INTO #IncludedPoll
FROM
(
-- Inner query makes sure member was actually enrolled for 2 yrs
SELECT LastPo, COUNT(*) AS Periods
FROM [Cye].[2_output_lastPoll] PO
WHERE PO.PollPq IN (1,2)
GROUP BY LastPo
) A
WHERE Periods IN (1,2) AND A.LastPo NOT IN (SELECT LastPo FROM #FilterPoll)
#FilterPoll是一个临时表,我很好,并包含一些我想从#IncludedPoll临时表中过滤掉的ID .
我已经看过其他答案,但它们都与连接有关,这不应该是问题.
我想转换一个字符串,比如
20/01/2017 10:46:19 AM
至
2017-01-20 10:46:19 AM
在Oracle中 伙计们好吗？我尝试使用to_date和to_timestamp但它没有用!
我按顺序列出了这个项目表:
orderitemid orderid itemid quantity price createdate
1 1 12 5 15.5 2016-12-04 11:35:02.06629
2 1 17 5 13.2 2016-12-04 11:32:02.06629
3 2 12 2 12.5 2016-12-05 11:35:02.06629
4 2 17 1 12.6 2016-12-05 11:35:02.06629
5 2 18 15 14.5 2016-12-04 11:35:02.06629
6 3 12 45 3 2015-12-04 11:35:02.06629
我有一个查询,它给出了每个项目的最新顺序,所以:
select distinct on (itemid) *
from orderitems
order by itemid,createdate
这给了:
orderitemid orderid itemid quantity price createdate
3 2 12 2 12.5 2016-12-05 11:35:02.06629
4 2 17 1 12.6 2016-12-05 …我有以下架构：
create table Took(
sID integer,
oID integer,
grade integer);
INSERT INTO Took VALUES
(1, 1, 90),
(1, 2, 100),
(2, 1, 90),
(2, 3, 80),
(2, 4, 85)
;
我也有以下查询：
(select sid from took) except all (select sid from took where grade < 90);
1,1,2由于在这种情况下等级值> = 90 ，因此产生了预期的输出。但是，当我删除该all子句以
select sid from took) except (select sid from took where grade < 90);
输出为1。我知道all确定是否存在重复项，因此在这种情况下，我希望输出1,2不是1。发生什么了？
我正在尝试将GMT转换为IST.
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSSS");
Date c= sdf.parse("2017-03-31T10:38:14.4723017Z");
Date date = new Date();
DateFormat istFormat = new SimpleDateFormat();
DateFormat gmtFormat = new SimpleDateFormat();
TimeZone gmtTime = TimeZone.getTimeZone("GMT");
TimeZone istTime = TimeZone.getTimeZone("IST");
istFormat.setTimeZone(gmtTime);
gmtFormat.setTimeZone(istTime);
System.out.println("GMT Time: " + istFormat.format(c));
System.out.println("IST Time: " + gmtFormat.format(c));
我的输出是
GMT Time: 31/3/17 6:26 AM
IST Time: 31/3/17 11:56 AM
但我的实际输出应该是
GMT Time: 31/3/17 5:08 AM
IST Time: 31/3/17 10:38 AM
我的代码出了什么问题？
所以我对Postgresql很新,并开始使用Postgres9.6上的pgadmin4测试一些东西.
问题:
我有一个表:test(id,text)
在这个表中,我有10行数据.现在我想导入一个包含12行的CSV来更新测试表.前10行中的某些文本已更改,我想从CSV中插入另外2行.
我知道你可以从表中截断所有数据,然后再从CSV导入所有数据,但这不是一个很好的方法.我想更新现有数据并使用一个查询插入新数据.
我已经找到了一个应该通过使用临时表来解决这个问题的函数.这会更新现有行的正确性,但不会插入另外2行
CREATE OR REPLACE FUNCTION upsert_test(integer,varchar) RETURNS VOID AS $$
DECLARE
BEGIN
UPDATE test
SET id = tmp_table.id,
text = tmp_table.text
FROM tmp_table
WHERE test.id = tmp_table.id;
IF NOT FOUND THEN
INSERT INTO test(id,text) values
(tmp_table.id,tmp_table.text);
END IF;
END;
$$ Language 'plpgsql';
DO $$ BEGIN
PERFORM upsert_test(id,text) FROM test;
END $$;
那么我还需要更改以使插件工作？
我正在尝试运行条件插入语句，但遇到问题。声明如下：
insert into category_content (category_id, content_id, content_type_id, priority) (select 29, id, 1, 1 from article where blog_id = 80)
where not exists(
select * from category_content where category_id = 29 and firstname in (select id from article where blog_id = 80)
);
这是我得到的错误：
insert into category_content (category_id, content_id, content_type_id, priority) (select 29, id, 1, 1 from article where blog_id = 80)
where not exists(
select * from category_content where category_id = 29 and firstname in (select id from article where …我有下表:
SELECT *
FROM mytable
ORDER BY id;
id name code time
1 A 111 1
2 A 111 2
3 A 888 3
4 A 888 4
5 A 888 5
6 A 888 6
7 A 888 7
8 A 111 8
9 A 111 9
10 A 111 10
我需要得到这样的结果:
name code times_between
A 111 1,2
A 888 3,7
A 111 8,10
是否可以按"块"分组？我需要根据时间进行区分,所以我不能只按名称,代码分组,只获取第一个和最后一个元素.