Questions tagged [sql]
Structured Query Language (SQL) is a language for querying databases. Questions should include code examples, table structure, sample data, and a tag for the DBMS implementation (e.g. MySQL, PostgreSQL, Oracle, MS SQL Server, IBM DB2, etc.) being used. If your question relates solely to a specific DBMS (uses specific extensions/features), use that DBMS's tag instead. Answers to questions tagged with SQL should use ISO/IEC standard SQL.
155,454
questions with no upvoted or accepted answers
23
votes
1
answer
719
views
ODCIAggregateMerge without parallel_enabled
These are quotes from Oracle docs:
[Optional] Merge by combining the two aggregation contexts and return a single context. This operation combines the results of aggregation over subsets in order ...
- 954
19
votes
0
answers
2k
views
How can I control the SQL table aliases that Hibernate uses in its generated queries?
tl;dr: Hibernate automatically generates SQL table aliases in its queries like jurisdicti4_ or this_. Here's an example query:
SELECT
this_.id AS id2_6_3_,
this_....
- 3,300
17
votes
3
answers
3k
views
Azure SQL stored procedure ridiculously slow called from C#
Summary:
We have two identical databases, one on a local server, one on Azure.
We have a C# system that accesses these databases, calling stored procedures.
The stored procedures are running very, ...
- 732
15
votes
3
answers
1k
views
Doctrine - Multiple models referencing same id field in another model
I have a Files Model, and Multiple (currently 3) different other Models (Article, Job, Event) that can all have files, that are stored in the Files Model.
The problem is that when i generate the ...
- 3,970
13
votes
2
answers
321
views
SQL update is using old column value
Given this table
create table FOO
(
ID number(19) primary key,
DATE1 DATE default sysdate,
DATE2 DATE
);
DATE1 is initialized with sysdate when I insert a row, then set to null and then ...
- 5,038
13
votes
1
answer
9k
views
How to create an empty array of struct in hive?
I have a view in Hive 1.1.0, based on a condition, it should return an empty array or an array of struct<name: string, jobslots: int>
Here is my code:
select
case when <condition>
...
- 955
13
votes
0
answers
4k
views
Postgresql: partial foreign key?
Is it possible to create a partial foreign key (similar to partial indexes) in general sql / postgresql? I have not found a way to force referential integrity in the following case:
Table A is soft-...
- 2,019
12
votes
7
answers
3k
views
Insert row if not exists without deadlock
I have a simple table
CREATE TABLE test (
col INT,
data TEXT,
KEY (col)
);
and a simple transaction
START TRANSACTION;
SELECT * FROM test WHERE col = 4 FOR UPDATE;
-- If no results, ...
- 6,955
11
votes
1
answer
6k
views
How to get all tables detailed information under specific schema in AWS Athena
I am getting the tables detailed information in Hive with the below query, but I am not finding the equivalent in Athena.
use schema_name;
SHOW TABLE EXTENDED LIKE '*'
As part of the output of above ...
- 547
11
votes
3
answers
4k
views
Sequelize query with a where clause on an include of an include
I'm struggling to create a query with sequelize.
Some context
I have the following models:
A Manifestation can have [0..n] Event
An Event belongs to one Manifestation (an Event cannot exist without ...
- 11.1k
11
votes
1
answer
7k
views
Choose a random row as aggregate function in Hive
I want to group by a column and then select random rows from another column. In Presto, there's arbitrary.
E.g. my query is:
SELECT a, arbitrary(b)
FROM foo
GROUP BY a
How do I do this in Hive?
...
- 25.6k
11
votes
1
answer
12k
views
Check if the unique constraint exists and drop it using liquibase
I have a changeset wherein I initially check if the unique constraint exists and then if it does it will drop the constraint.
<changeSet author="loren"
id="...
- 1,280
11
votes
1
answer
3k
views
How to map native sql results to oneToMany field with SqlResultSetMapping in JPA
For example, say I have the following database tables
Building
-----------
id
name
and
Room
-----------
id
roomNo
buildingId
the Building Java class will look something like
@Entity
public class ...
- 1,674
10
votes
1
answer
282
views
How to fetch all rows which will be removed on using cascading delete before delete query
What is the best approach to fetch all the rows, which will be deleted on cascade of primary key?
At present we know the list of tables which uses the primary key as foreign key, a simple select query ...
- 575
10
votes
2
answers
14k
views
Missing comma before start of a new alter operation. (near "CHARACTER SET")
Mysql - phpmyadmin
What's wrong with this query?
ALTER TABLE `invoices`
CHANGE `status` `status` ENUM('paid','due','canceled','partial','cheque')
CHARACTER SET `utf8` COLLATE `utf8_general_ci` NOT ...
- 518