i have this table:
(`id`, `name`, `type`, `price`)
(1, 'cats', 1, 12.25),
(2, 'dogs', 0, 11.35),
(3, 'house', 1, 7.25),
(4, 'cats2', 2, 5.26);
I need select all data, but if type is 1, i need get items witch price is more than 10.
I create this query:
SELECT *
FROM `items`
WHERE IF(TYPE = "1", price > 10, 1 = 1)
Works well, but maybe possible write much smarter or in other way?
Maybe don't need "1 = 1"?.
I would like to know your advice, thanks
Your 1=1 is senseless, but your IF is not. You can use just 1:
SELECT *
FROM `items`
WHERE IF(TYPE = "1", price > 10, 1)
-since MySQL evaluates expression as bool (actually, int) - and so 1 means 'true'.
But on the other hand, there's logic equivalent for your condition:
SELECT *
FROM `items`
WHERE `price`>10 OR `type`!="1"
However, I've faced such case in another question and, after some researching, I've discovered that IF is faster, even if it looks more complicated.
Related
i have 2 query first one is
SELECT stdntCode
FROM dbo.CourseStudent
WHERE(Status = 'Active') AND (CrsID = 1) AND (GrpID = 8)
second one is insert
INSERT INTO StudentExam (ExamID, CrsID, stdntCode, [Degree], StudGrpID, IsAttend, Notes, dateexam, [date])
VALUES(4, 3, stdntCode, 8.0, 1, 1, N'', '2023-01-17', '2023-02-01');
i want to insert this data to my first query i want replace stdntCode in my insert query with stdntCode list from my first query
thank you
i try that query
insert into StudentExam (stdntCode ,ExamID, CrsID, [Degree], StudGrpID, IsAttend, Notes, dateexam, [date])
select (SELECT stdntCode
FROM dbo.CourseStudent
WHERE(Status = 'Active') AND (CrsID = 1) AND (GrpID = 8)) as IDClient,
(4, 3,0, 1, 1, N'', '2023-01-17', '2023-02-01');
You need to provide the column values as part of a single select statement, like the following:
insert into StudentExam (stdntCode ,ExamID, CrsID, [Degree], StudGrpID, IsAttend, Notes, dateexam, [date])
select stdntCode, 4, 3, 0, 1, 1, N'', '2023-01-17', '2023-02-01'
from dbo.CourseStudent
where Status = 'Active' and CrsID = 1 and GrpID = 8;
I have the following table data:
content,count
'a', '1'
'b', '2'
'c', '2'
'd', '2'
'content_name', '18'
'de', '2'
'dea', '2'
'deaasdfdsaf', '5'
'content_name', '17'
I would like to have the correct query for getting x (for example 4) rows with the biggest values in their content column
I have tried the answers given in:
Getting Top 3 from Mysql table based on Condition/Value
but it didnt work as i was expecting
it keeps giving me just the rows by their table location
any suggestions?
create table Test(content varchar(100),count integer );
insert into Test(content, count) values("a", 1);
insert into Test(content, count) values("b", 2);
insert into Test(content, count) values("c", 2);
insert into Test(content, count) values("d", 2);
insert into Test(content, count) values("content_name", 18);
insert into Test(content, count) values("de", 2);
insert into Test(content, count) values("dea", 2);
insert into Test(content, count) values("deaasdfdsaf", 5);
insert into Test(content, count) values("content_name", 7);
select * from Test
order by count desc
limit 4;
However, I am not quite sure what you mean by "biggest values in their content column", therefore I ranked by their count values.
If you are actually looking for the number of character within the content column, which was my initial impression reading your question:
Using Martin Stagl's post to create the example table .
select *, LENGTH(REPLACE(content, 'N', '')) as char_length from Test;
NOTE: If this is not working on the server, try replacing the LENGTH() function with LEN()
Fiddle: http://sqlfiddle.com/#!9/032d48/9
I'm trying to update the database, using a script where the ID of a user isn't readily known, so I'm using a subquery to have mysql find the user id (for the posteruserid value). This is the SQL query i'm using:
INSERT INTO `thread` (`title`, `forumid`, `open`, `replycount`,
`postercount`, `postusername`, `postuserid`, `lastposter`,
`dateline`, `visible`, `keywords`)
SELECT 'IN', 2, 1, 0, 1, 'lemons', `userid` FROM `user`
WHERE `username` = 'lemons', 'lemons', 1375768440, 1, 'IN';
I'm getting a syntax error from the above SQL, and I can't figure out what I'm doing wrong.
EDIT because of the mismatched column name, I tried using an alias, which still doesn't work
INSERT INTO `thread` (`title`, `forumid`, `open`, `replycount`,
`postercount`, `postusername`, `postuserid`, `lastposter`,
`dateline`, `visible`, `keywords`)
SELECT 'IN', 2, 1, 0, 1, 'lemons',
`userid` AS `postuserid` FROM `user` WHERE `username` = 'lemons',
'lemons', 1375768440, 1, 'IN';
column mismatch in insert and select query..column should be same where you are going to insert and from where you are fetching data.
You specify to insert values of 11 columns, but in your SELECT statement, you are providing only 7 values. Please provide the value for lastposter,dateline,visible, and keywords.
I'm transferring over some queries from MySQL to PostgreSQL and I'm stumped on how to rewrite the following query to work in PostgreSQL:
SUM(phoneid IN (1, 2, 6, 8)) AS completedcalls
I originally thought I could just do SUM(SELECT phoneid FROM myTable WHERE phoneid = 1 OR phoneid = 2 etc etc, but I do not believe you can have a SELECT within a sum.
I also tried using a WITH query but had no luck getting that to work.
how about using CASE
SUM(CASE WHEN phoneid IN (1, 2, 6, 8) THEN 1 ELSE 0 END)
count(phoneid in (1,2,6,8) or null)
bool may be cast to integer:
SUM(CAST(phoneid IN (1, 2, 6, 8) AS INTEGER)) AS completedcalls
On an old project because of not thought through design I have a column which actually should be set to auto_increment, though it cannot be because it are alphanumeric entries as follows:
c01
c02
c03
(c99 would continue to c100 and more), the letter happened in the past and it would require to overhaul the system to take it out, thus I rather prefer this workaround.
Now I need a way to imitate the auto_increment functionality with the SQL statement myself, my own attempt has gotten as far as the following:
INSERT INTO tags (tag_id, tag_name, tag_description, added_by_user_id, creation_date, last_edited) VALUES (SELECT(MAX(tag_id)+1),
'Love', 'All about love', 7, now(), 0);
This one does not work as is, though the idea was to select the highest entry in the column "tag_id" and then simply increase it by the value 1.
Any ideas how to accomplish this?
By the way I am also not sure if you simply can increase an alphanumeric entry through this way, though I know it can be done, I just don't know how.
If you want to safely get the largest integer value of a tag id of the form c##.., you could use the following expression:
max( convert( substring(tag_id, 2) , unsigned integer) )
^^^ largest ^^^^^^^^^ after 'c' ^^^^^^^^^^^^^^^^ convert to positive number
Then your insert statement would look something like this:
set #newid = convert(
(select
max(convert( (substring(tag_id, 2)) , unsigned integer))+1
from tags), char(10)
);
set #newid = if(length(#newid) = 1, concat('0', #newid), #newid);
set #newid = concat('c', #newid);
INSERT INTO tags (tag_id, tag_name, tag_description, added_by_user_id,
creation_date, last_edited)
VALUES (#newid, 'Love', 'All about love', 7, now(), '2012-04-15');
Demo: http://www.sqlfiddle.com/#!2/0bd9f/1
this will increase from c01 to c02 to c03 ... to c99 to c100 to c101 ... to c999 to c1000 etc.
set #nextID = (SELECT CONCAT(SUBSTRING(`tag_id`, 1, 1), IF(CHAR_LENGTH(CAST(SUBSTRING(`tag_id`, 2)
AS UNSIGNED)) < 2, LPAD(CAST(CAST(SUBSTRING(`tag_id`, 2) AS UNSIGNED) + 1 AS CHAR), 2,
'0'), CAST(CAST(SUBSTRING(`tag_id`, 2) AS UNSIGNED) + 1 AS CHAR))) FROM `tags` ORDER BY
`tag_id` DESC LIMIT 1);
INSERT INTO tags (tag_id, tag_name, tag_description, added_by_user_id,
creation_date, last_edited) VALUES (#nextID, 'Love', 'All about love', 7, NOW(), null);