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How to create a MySQL hierarchical recursive query
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For MySQL 8+: use the recursive with syntax.
For MySQL 5.x: use inline variables, path IDs, or self-joins.
MySQL 8+
with recursive cte (id, name, parent_id) as (
select id,
name,
parent_id
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ActiveRecord.find(array_of_ids), preserving order
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The answer is for mysql only
There is a function in mysql called FIELD()
Here is how you could use it in .find():
>> ids = [100, 1, 6]
=> [100, 1, 6]
>> WordDocument.find(ids).collect(&:id)
=> [1, 6, 100]
>> W...
SQL Server query to find all permissions/access for all users in a database
...ocedures, either directly or due to roles, etc. This report would be used for security auditing purposes. Not sure if anyone has a query that will fit my needs completely, but hopefully something that will give me a good start. Either sql 2008, 2005 or 2000 will do, I can probably convert as neede...
Naming of ID columns in database tables
... be copying the join syntax (don't tell me that no one ever does this!)and forget to change the alias in the join condition.
So you now have
select t1.field1, t2.field2, t3.field3
from table1 t1
join table2 t2 on t1.id = t2.table1id
join table3 t3 on t1.id = t3.table2id
when you meant
select ...
Export database schema into SQL file
...ere are the steps:
Right click the database you want to generate scripts for (not the table) and select tasks - generate scripts
Next, select the requested table/tables, views, stored procedures, etc (from select specific database objects)
Click advanced - select the types of data to script
Clic...
PostgreSQL function for last inserted ID
...NSERT with RETURNING )
Recall that in postgresql there is no "id" concept for tables, just sequences (which are typically but not necessarily used as default values for surrogate primary keys, with the SERIAL pseudo-type).
If you are interested in getting the id of a newly inserted row, there are...
How can I assign an ID to a view programmatically?
...XML (when possible) and via code (programmatically.) The id is most useful for getting references for XML-defined Views generated by an Inflater (such as by using setContentView.)
Assign id via XML
Add an attribute of android:id="@+id/somename" to your view.
When your application is built, the an...
MySQL JOIN the most recent row only?
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You may want to try the following:
SELECT CONCAT(title, ' ', forename, ' ', surname) AS name
FROM customer c
JOIN (
SELECT MAX(id) max_id, customer_id
FROM customer_data
GROUP BY customer_id
) c_max ON (c_max.cust...
SQL query return data from multiple tables
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Joining two or more tables using an inner join (See the wikipedia entry for additional info)
How to use a union query
Left and Right Outer Joins (this stackOverflow answer is excellent to describe types of joins)
Intersect queries (and how to reproduce them if your database doesn't support them) ...
Select first row in each GROUP BY group?
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Informix 12.x also supports window functions (the CTE needs to be converted to a derived table though). And Firebird 3.0 will also support Window functions
– a_horse_with_no_name
Mar 14 '1...