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1052: Column 'id' in field list is ambiguous
...
SQL supports qualifying a column by prefixing the reference with either the full table name:
SELECT tbl_names.id, tbl_section.id, name, section
FROM tbl_names
JOIN tbl_section ON tbl_section.id = tbl_names.id
...or a table alias:
SELECT n.id, s.id, n.n...
SQL DROP TABLE foreign key constraint
... still the same 'Could not drop object 'my_table' because it is referenced by a FOREIGN KEY constraint.
– FrenkyB
Nov 16 '15 at 13:00
7
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How to break a line of chained methods in Python?
...uery(Subkeyword.subkeyword_id, Subkeyword.subkeyword_word)
.filter_by(subkeyword_company_id=self.e_company_id)
.filter_by(subkeyword_word=subkeyword_word)
.filter_by(subkeyword_active=True)
.one()
)
...
How to concatenate strings of a string field in a PostgreSQL 'group by' query?
... am looking for a way to concatenate the strings of a field within a group by query. So for example, I have a table:
14 Ans...
ssh “permissions are too open” error
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Keys need to be only readable by you:
chmod 400 ~/.ssh/id_rsa
If Keys need to be read-writable by you:
chmod 600 ~/.ssh/id_rsa
600 appears to be fine as well (in fact better in most cases, because you don't need to change file permissions later to e...
Find the index of a dict within a list, by matching the dict's value
...ne)
# 1
If you need to fetch repeatedly from name, you should index them by name (using a dictionary), this way get operations would be O(1) time. An idea:
def build_dict(seq, key):
return dict((d[key], dict(d, index=index)) for (index, d) in enumerate(seq))
info_by_name = build_dict(lst, ke...
What is the standard naming convention for html/css ids and classes?
...ning off, but it's interesting the compiler strongly suggests a convention by default. I imagine in larger projects it leads to cleaner code which is no bad thing.
Update 2016 (you asked for it)
I've adopted the BEM standard for my projects going forward. The class names end up being quite verbose...
How to count occurrences of a column value efficiently in SQL?
...
This should work:
SELECT age, count(age)
FROM Students
GROUP by age
If you need the id as well you could include the above as a sub query like so:
SELECT S.id, S.age, C.cnt
FROM Students S
INNER JOIN (SELECT age, count(age) as cnt
FROM Students
...
What is the X-REQUEST-ID http header?
...
When you're operating a webservice that is accessed by clients, it might be difficult to correlate requests (that a client can see) with server logs (that the server can see).
The idea of the X-Request-ID is that a client can create some random ID and pass it to the server. T...
What is the easiest way to ignore a JPA field during persistence?
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To ignore a field, annotate it with @Transient so it will not be mapped by hibernate.
but then jackson will not serialize the field when converting to JSON.
If you need mix JPA with JSON(omit by JPA but still include in Jackson) use @JsonInclude :
@JsonInclude()
@Transient
private String token...