I have a .Net mobile service.
Calling this:
https://xxx.azure-mobile.net/tables/items?$filter=(company%20eq%20%27987af3f9-8d44-4a9d-8be2-7e0567287106%27)
Returns:
{"message":"The query specified in the URI is not valid. Could not
find a property named 'company' on type
'Default.<>f__AnonymousType2_3OfString_String_Double'."}
The field name in the "items" entity model is "company" and on the database is "company_Id", neither will work.
Using http://ajax.aspnetcdn.com/ajax/mobileservices/MobileServices.Web-1.2.5.min.js
What could be wrong?
It turns out that you are running into a casing bug in the .NET backend when $select or $filter is used. The workaround is to use Pascal case (i.e., uppercase first letter) for your property names.
Problem was that you can only filter a field that is present in the $select clause. As said here
Doesn't make sense but anyway...
Having the first character as lower case for my column names prevented me from querying my Azure database with LINQ or Lambda expressions.
Switching them to upper case letters did the trick.
Related
I'm using pg-promise and am not understanding how to run this query. The first query works, but I would like to use pg-promise's safe character escaping, and then I try the second query it doesn't work.
Works:
db.any(`SELECT title FROM books WHERE id = ANY ('{${ids}}') ORDER BY id`)
Doesn't work
db.any(`SELECT title FROM books WHERE id = ANY ($1) ORDER BY id`, ids)
The example has 2 problems. First, it goes against what the documentation tells you:
IMPORTANT: Never use the reserved ${} syntax inside ES6 template strings, as those have no knowledge of how to format values for PostgreSQL. Inside ES6 template strings you should only use one of the 4 alternatives - $(), $<>, $[] or $//.
Manual query formatting, like in your first example, is a very bad practice, resulting in bad things, ranging from broken queries to SQL injection.
And the second issue is that after switching to the correct SQL formatting, you should use the CSV Filter to properly format the list of values:
db.any(`SELECT title FROM books WHERE id IN ($/ids:csv/) ORDER BY id`, {ids})
or via an index variable:
db.any(`SELECT title FROM books WHERE id IN ($1:csv) ORDER BY id`, [ids])
Note that I also changed from ANY to IN operand, as we are providing a list of open values here.
And you can use filter :list interchangeably, whichever you like.
I am new to JPA named queries using EclipseLink and I want to "ignore" properties with null values in named query. I know that my question has been answered many times.
e.g. JPA Query to handle NULL parameter value
However, in my case following format is not working
+ " AND (:quoteNumber IS NULL OR ord.quoteNumber = :quoteNumber)"
I am getting error 'ILLEGAL USE OF KEYWORD NULL'. I will be using CriteriaQuery now and just curious why it is not working in named query.
Following are the DB2 and Eclipselink versions being used.
eclipselink: 2.5.1
DB2: DSN11015
The JPA Specification says that
3.8.13 Named Queries
Named queries are static queries expressed in metadata. Named queries can be defined in the Java Persistence query language or in SQL. Query names are scoped to the persistence unit.
So you can't really expect them to change on runtime based on some null condition. Criteria Query, as you point out, is dynamic by nature, so would be the way to go.
EDIT based on comment:
AND (ord.quoteNumber = :quoteNumber or :quoteNumber is null or :quoteNumber = ''
does not change the query on runtime (does not skip the clause). It evaluates the clause as TRUE. The problem with DB2 (and Derby as far as I know) is, that they do not allow "non-typed Null to be sent to the backend" as per API PreparedStatement.setObject. You can test it by setting the type via casting
AND (ord.quoteNumber = cast(:dfdTxt as integer) or cast(:dfdTxt as integer) is null or cast(:dfdTxt as integer) = ''
So this approach is DB Implementation specific and might change at some point.
I've got a table TABLE that contains a jsonb column named tags. The tags element in each row may or may not contain a field called group. My goal is to group by tags.group for all rows where tags contains a group field. Like the following postgres query:
select tags->>'group' as group, sum(n) as sum
from TABLE
where tags ? 'group'
group by tags->>'group';
I'm trying to turn it into JOOQ and cannot find out how to express the where tags ? 'group' condition.
For example,
val selectGroup = DSL.field("{0}->>'{1}'", String::class.java, TABLE.TAGS, "group")
dsl().select(selectGroup, DSL.sum(TABLE.N))
.from(TABLE)
.where(TABLE.TAGS.contains('group'))
.groupBy(selectGroup)
This is equivalent to testing contains condition #> in postgres. But I need to do exists condition ?. How can I express that in JOOQ?
There are two things worth mentioning here:
The ? operator in JDBC
Unfortunately, there's no good solution to this as ? is currently strictly limited to be used as a bind variable placeholder in the PostgreSQL JDBC driver. So, even if you could find a way to send that character to the server through jOOQ, the JDBC driver would still misinterpret it.
A workaround is documented in this Stack Overflow question.
Plain SQL and string literals
When you're using the plain SQL templating language in jOOQ, beware that there is a parser that will parse certain tokens of your string, including e.g. comments and string literals. This means that your usage of...
DSL.field("{0}->>'{1}'", String::class.java, TABLE.TAGS, "group")
is incorrect, as '{1}' will be parsed as a string literal and sent to the server as is. If you want to use a variable string literal, do this instead:
DSL.field("{0}->>{1}", String::class.java, TABLE.TAGS, DSL.inline("group"))
See also DSL.inline()
i think this can be a bug in yii2,
when i use:
$query->select ("isnull(cba.HSLET,0)");
$query->join('INNER JOIN','cba','cba.id = regverification.cba_id');
yii miss create the sql sentence resulting in a error near:
isnull(cba.HSLET, [0)]
From Yii 2 Guide:
Besides column names, you can also select DB expressions. You must use the array format when selecting a DB expression that contains commas to avoid incorrect automatic name quoting.
So it should be:
$query->select(["ISNULL(cba.HSLET, 0)"]);
The RFC6020 says:
The "key" statement [...] takes as an argument a
string that specifies a space-separated list of leaf identifiers of
this list. [...] Each such leaf identifier MUST refer to a child leaf of the
list. The leafs can be defined directly in substatements to the
list, or in groupings used in the list.
Despite this fact it is possible to successfully validate the below grouping in pyang:
grouping my-grouping {
list my-list-in-a-grouping {
key there-is-no-such-leaf;
}
}
If the list is outside of a grouping, or if I use the grouping without any augmentations, then I get an error (which is expected):
error: the key "there-is-no-such-leaf" does not reference an existing leaf
What is the point of having groupings that require augmentations in order to be used?
According to Martin Bjorklund, an author of the related RFCs, this is not valid YANG. Pyang fails to detect this due to a bug in its implementation. The RFC text which you quoted in your question does not permit any other interpretation and appears to be intentional. Groupings were never meant to be used in such a way.
Could it be because grouping is not a data definition node and pyang validates only such nodes?
The grouping statement is not a data
definition statement and, as such, does not define any nodes in
the schema tree.
RFC6020