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How to test an SQL Update statement before running it?
...man/5.0/en/commit.html
For example:
START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check
COMMIT;
# or if you want to reset changes
ROLLBACK;
SELECT * FROM nicetable WHERE somthing=1...
JPA EntityManager: Why use persist() over merge()?
...nate Session (a.k.a Persistence Context) and is not mapped to any database table row is considered to be in the New (Transient) state.
To become persisted we need to either explicitly call the EntityManager#persist method or make use of the transitive persistence mechanism.
Persistent (Managed)
A...
Use a LIKE statement on SQL Server XML Datatype
If you have a varchar field you can easily do SELECT * FROM TABLE WHERE ColumnA LIKE '%Test%' to see if that column contains a certain string.
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How do I use LINQ Contains(string[]) instead of Contains(string)
...ids = arrayofuids.Select(id => int.Parse(id)).ToList();
var selected = table.Where(t => uids.Contains(t.uid));
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What's the difference between VARCHAR and CHAR?
...: when Anon. says "your content is a fixed size" it means the rows of your table must contain all fixed size fields. You get no performance improvement if you use CHAR against VARCHAR in one field, but the table contains other fields that are VARCHAR.
– Marco Demaio
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Query for array elements inside JSON type
... json type in PostgreSQL 9.3.
I have a json column called data in a table called reports . The JSON looks something like this:
...
Swipe to Delete and the “More” button (like in Mail app on iOS 7)
How to create a "more" button when user swipe a cell in table view (like mail app in ios 7)
20 Answers
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What MySQL data type should be used for Latitude/Longitude with 8 decimal places?
...types and Point is a single-value type which can be used. Example:
CREATE TABLE `buildings` (
`coordinate` POINT NOT NULL,
/* Even from v5.7.5 you can define an index for it */
SPATIAL INDEX `SPATIAL` (`coordinate`)
) ENGINE=InnoDB;
/* then for insertion you can */
INSERT INTO `buildings`
(...
Command line CSV viewer? [closed]
...ropriate width of each column, and displays the text as a nicely formatted table.
Note: whenever you have empty fields, you need to put some kind of placeholder in it, otherwise the column gets merged with following columns. The following example demonstrates how to use sed to insert a placeholder:...
Add a custom attribute to a Laravel / Eloquent model on load?
...s any accessors which do not directly relate to a column in the underlying table.
As Taylor Otwell mentioned here, "This is intentional and for performance reasons." However there is an easy way to achieve this:
class EventSession extends Eloquent {
protected $table = 'sessions';
protecte...