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Validate uniqueness of multiple columns
...record is unique and not just a column? For example, a friendship model / table should not be able to have multiple identical records like:
...
Are GUID collisions possible?
...ither unique (for things like version 1 GUIDs), or both unique and unpredictable (for things like version 4 GUIDs). SQL Server's implementation for their NEWID() function appears to use a 128-bit random number, so you're not going to get a collision.
For a 1% chance of collision, you'd need to gen...
How to make Entity Framework Data Context Readonly
... db_datareader only sql login? With a standard DBContext EF throws CREATE TABLE permission denied even when my query code doesn't include any SaveChanges().
– reachingnexus
Mar 20 '19 at 20:02
...
When to use static vs instantiated classes
...y the code is much more extensible and, the most important part for me, testable. Why is it more important to be testable? Because I don't always write library code, so extensibility is not that important, but testability is important when I do refactoring. Anyways, testable code usually yields exte...
How do I query between two dates using MySQL?
...
Your query should have date as
select * from table between `lowerdate` and `upperdate`
try
SELECT * FROM `objects`
WHERE (date_field BETWEEN '2010-01-30 14:15:55' AND '2010-09-29 10:15:55')
...
How to select where ID in Array Rails ActiveRecord without exception
...
If you need more control (perhaps you need to state the table name) you can also do the following:
Model.joins(:another_model_table_name)
.where('another_model_table_name.id IN (?)', your_id_array)
sh...
Postgres: “ERROR: cached plan must not change result type”
...ement for execution.
Meanwhile, another script was modifying the database table, changing the data type of one of the columns being returned in the above SELECT statement.
I resolved this by restarting the application after the database table was modified. This reset the database connection, allow...
SELECT * WHERE NOT EXISTS
...
You didn't join the table in your query.
Your original query will always return nothing unless there are no records at all in eotm_dyn, in which case it will return everything.
Assuming these tables should be joined on employeeID, use the foll...
What is PAGEIOLATCH_SH wait type in SQL Server?
...stem.
In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.
If your query is like this:
Select * from <table> where <col1> = <value> order by <PrimaryKey>
, check that you have a composit...
Are there constants in JavaScript?
...nly enjoys a smattering of browser support: http://kangax.github.io/compat-table/es6/. The syntax is:
const CONSTANT_NAME = 0;
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