hi i am executing nested "select" query in mysql .
the query is
SELECT `btitle` FROM `backlog` WHERE `bid` in (SELECT `abacklog_id` FROM `asprint` WHERE `aid`=184 )
I am not getting expected answer by the above query. If I execute:
SELECT abacklog_id FROM asprint WHERE aid=184
separately
I will get abacklog_id as 42,43,44,45;
So if again I execute:
SELECT `btitle` FROM `backlog` WHERE `bid` in(42,43,44,45)
I will get btitle as scrum1 scrum2 scrum3 msoffice
But if I combine those queries I will get only scrum1 remaining 3 atitle will not get.
You Can Try As Like Following...
SELECT `age_backlog`.`ab_title` FROM `age_backlog` LEFT JOIN `age_sprint` ON `age_backlog`.`ab_id` = `age_sprint`.`as_backlog_id` WHERE `age_sprint`.`as_id` = 184
By using this query you will get result with loop . You will be able to get all result with same by place with comma separated by using IMPLODE function ..
May it will be helpful for you... If you get any error , Please inform me...
What you did is to store comma separated values in age_sprint.as_backlog_id, right?
Your query actually becomes
SELECT `ab_title` FROM `age_backlog` WHERE `ab_id` IN ('42,43,44,45')
Note the ' in the IN() function. You don't get separate numbers, you get one string.
Now, when you do
SELECT CAST('42,43,44,45' AS SIGNED)
which basically is the implicit cast MySQL does, the result is 42. That's why you just get scrum1 as result.
You can search for dozens of answers to this problem here on SO.
You should never ever store comma separated values in a database. It violates the first normal form. In most cases databases are in third normal form or BCNF or even higher. Lower normal forms are just used in some special cases to get the most performance, usually for reporting issues. Not for actually working with data. You want 1 row for every as_backlog_id.
Again, your primary goal should be to get a better database design, not to write some crazy functions to get each comma separated number out of the field.
Related
I'm working on a MySQL Way of printing an "affiliate tree" and got the thing working with Common Table Expression. I'm using the following code right now:
WITH RECURSIVE recUsers AS
(
SELECT ID, username, sponsorID, 1 AS depth, username AS path
FROM users
WHERE id = 1
UNION ALL
SELECT c.ID, c.username, c.sponsorID, sc.depth + 1, CONCAT(sc.path, ' > ', c.username)
FROM recUsers AS sc
JOIN users AS c ON sc.ID = c.sponsorID
)
SELECT * FROM recUsers;
This selects the tree underneath the user with the id 1.
Now what I'd need to get is a way to pass that id as a parameter, so I don't need to define everything from the beginning every time I want to get the result.. So my idea is to put everything in a stored prodecure and pass the id in as a parameter.. However, so far I didn't get it working and always getting various errors that are very self speaking...
Basically what I've tried was
DELIMITER //
CREATE PROCEDURE getAffiliateTree(IN userid INT())
BEGIN
---my code here, the userid 1 replaced with userid
END//
DELIMITER;
However, this doesn't seem to work.. How can I get this done?
Two things I would suggest:
Use INT, not INT(). The optional length argument to integer types is deprecated in MySQL 8.0 (which I know you're using, because you're using CTE syntax). Even if you did use the length argument, using an empty argument is not legal syntax.
Make sure that the userid input parameter name is distinct from all of the columns in the tables you reference. That is, if the table has a column named userid (any capitalization), then change the name of your input parameter. Otherwise you may make ambiguous expressions like:
... WHERE userid = userid
Even though you intend one of these to be the column and the other to be the parameter, the SQL parser has no way of knowing that. It ends up treating both as the column name, so it's trivially true on all rows of the table.
Actually, a third thing I would suggest: when you ask questions, "it doesn't seem to work" isn't clear enough. Did it produce an error? If so, what was the full error message? Did it produce no error, but didn't give you the result you wanted? If so, show a mocked-up example of what you expected, and what the query produced that didn't match. It helps to be as clear as you can when you post questions, so readers don't have to guess what trouble you need help with.
I've created a MySQL sproc which returns 3 separate result sets. I'm implementing the npm mysql package downstream to exec the sproc and get a result structured in json with the 3 result sets. I need the ability to filter the json result sets that are returned based on some type of indicator in each result set. For example, if I wanted to get the result set from the json response which deals specifically with Suppliers then I could use some type of js filter similar to this:
var supplierResultSet = mySqlJsonResults.filter(x => x.ResultType === 'SupplierResults');
I think SQL Server provides the ability to include a hard-coded column value in a SQL result set like this:
select
'SupplierResults',
*
from
supplier
However, this approach appears to be invalid in MySQL b/c MySQL Workbench is telling me that the sproc syntax is invalid and won't let me save the changes. Do you know if something like what I'm trying to achieve is possible in MySQL and if not then can you recommend alternative approaches that would help me achieve my ultimate goal of including some type of fixed indicator in each result set to provide a handle for downstream filtering of the json response?
If I followed you correctly, you just need to prefix * with the table name or alias:
select 'SupplierResults' hardcoded, s.* from supplier s
As far as I know, this is the SQL Standard. select * is valid only when no other expression is added in the selec clause; SQL Server is lax about this, but most other databases follow the standard.
It is also a good idea to assign a name to the column that contains the hardcoded value (I named it hardcoded in the above query).
In MySQL you can simply put the * first:
SELECT *, 'SupplierResults'
FROM supplier
Demo on dbfiddle
To be more specific, in your case, in your query you would need to do this
select
'SupplierResults',
supplier.* -- <-- this
from
supplier
Try this
create table a (f1 int);
insert into a values (1);
select 'xxx', f1, a.* from a;
Basically, if there are other fields in select, prefix '*' with table name or alias
I have a PostgreSQL table with a JSON column, and I'm trying to get a list of all the distinct keys in that column. I created a query to do this:
SELECT DISTINCT json_object_keys(j) FROM t;
Where t is the table and j is the JSON column. This worked on a small set of data correctly, it would list all the keys that exist in j, without repeating them. However, after adding a lot more data, it doesn't work anymore, giving the error:
ERROR: cannot call json_object_keys on a scalar
I'm not sure exactly why this is happening. By just limiting the query to certain rows one at a time, I found one that causes the error. In that row, j is null. However, calling SELECT json_object_keys(null); does not cause this error, while calling SELECT json_object_keys(j) FROM t WHERE id=12; does, and j in this row is just null. I'm not really sure where to go from here.
So I guess my question is what could be causing this, and how can I either work around it or prevent it from happening?
Running PostgreSQL 9.3.9
Edit: Ok, I may have posted this a little preemptively. I figured out that j in the problematic row isn't null, it's 'null'::json, which wasn't clear from just selecting the row. This does cause the scalar error, so now I just have to figure out a way to select the rows where j isn't 'null'::json.
I tried this query, to filter out the 'null'::json values with this query:
SELECT DISTINCT json_object_keys(j) from t WHERE j <> 'null'::json;
However, apparently there is no json <> json operator, so I had to cast it to text and compare.
SELECT DISTINCT json_object_keys(j) from t WHERE j::TEXT <> 'null';
This works! I'm not a Postgres expert though, so this may not be the most effecient way of doing this check.
I have this union statement when I try to take parameters from a form and pass it to a union select statement it says too many parameters. This is using MS ACCESS.
SELECT Statement FROM table 1 where Date = Between [Forms]![DateIN]![StartDate]
UNION
SELECT Statement FROM table 2 where Date = Between [Forms]![DateIN]![StartDate]
This is the first time I am using windows DB applications to do Database apps. I am Linux type of person and always use MySQL for my projects but for this one have to use MS Access.
Is there anther way to pass parameters to UNION Statement because this method of defining values in a form can work on Single SELECT statements. But I don't know why this problem exist.
Between "Determines whether the value of an expression falls within a specified range of values" like this ...
expr [Not] Between value1 And value2
But your query only gives it one value ... Between [Forms]![DateIN]![StartDate]
So you need to add And plus another date value ...
Between [Forms]![DateIN]![StartDate] And some_other_date
Also Date is a reserved word. If you're using it as a field name, enclose it in brackets to avoid confusing the db engine: [Date]
If practical, rename the field to avoid similar problems in the future.
And as Gord pointed out, you must also bracket table names which include a space. The same applies to field names.
Still getting problems when using this method of calling the values or dates from the form to be used on the UNION statement. Here is the actual query that I am trying to use.
I don't want to recreate the wheel but I was thinking that if the Date() can be used with between Date() and Date()-6 to represent a 7 days range then I might have to right a module that takes the values from the for and then returns the values that way I can do something like Sdate() and Edate() then this can be used with Between Sdate() and Edate().
I have not tried this yet but this can be my last option I don't even know if it will work but it is worth a try. But before i do that i want to try all the resources that Access can help me make my life easy such as its OO Stuff it has for helping DB programmers.
SELECT
"Expenditure" as [TransactionType], *
FROM
Expenditures
WHERE
(((Expenditures.DateofExpe) Between [Forms]!Form1![Text0] and [Forms]![Form1]![Text11]))
UNION
SELECT
"Income" as [TransactionType], *
FROM
Income
WHERE
(((Income.DateofIncom) Between [Forms]!Form1![Text0] and [Forms]![Form1]![Text11] ));
Access VBA has great power but I don't want to use it as of yet as it will be hard to modify changes for a user that does not know how to program. trying to keep this DB app simple as possible for a dumb user to fully operate.
Any comments is much appreciated.
It sounds more complicated than it actually is. Here is what I'm trying to do within the SELECT part:
SELECT TIMESTAMPADD(
UCASE(
SUBSTRING(offset_unit,1,CHAR_LENGTH(offset_unit)-1)
),1,'2003-01-02') as offset_date
offset_unit is a VARCHAR column in the database. It contains one of the following: "Hours","Minutes".
offset is an INT.
I am trying to convert the offset_unit to uppercase, after I have removed the last character ('s') so I can have a proper interval (MINUTE, HOUR...) so I can get a date that I can use in sorting afterwards, but MySQL keeps throwing an error. I have tested each step by adding one function at a time, and it only fails after I add TIMESTAMPADD. If I enter MINUTE manually then it works.
Any way to get this working?
Additional info: I am running this in CakePHP 1.3, in a find, within the 'fields' array, but that shouldn't be important.
this can be easily achived by using CASE WHEN clause as:
SELECT (CASE
WHEN offset_unit = 'HOURS'
THEN TIMESTAMPADD(HOUR,`offset`,'2003-01-02')
WHEN offset_unit = 'MINUTES'
THEN TIMESTAMPADD(MINUTE,`offset`,'2003-01-02')
END) AS offset_date
FROM my_table;
SEE SQLFIDDLE DEMO HERE
It doesn't work because TIMESTAMPADD does not take a string as the first argument, but a unit keyword, for example MINUTE. My guess is that you need to do this in two steps, first get the unit and then construct a query with the correct keyword.