大约有 5,890 项符合查询结果（耗时：0.0151秒） [XML]
Which data type for latitude and longitude?
... want to store latitude and longitude values in PostgreSQL 9.1.1 database table. I will calculate distance between two points, find nearer points by using this location values.
...
Real life example, when to use OUTER / CROSS APPLY in SQL
...ORDER BY pr.name) pa
ORDER BY pr.name,
pa.name
2) Calling a Table Valued Function for each row in the outer query
SELECT *
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle)
3) Reusing a column alias
SELECT number,
doubled_number,
...
How does a hash table work?
I'm looking for an explanation of how a hash table works - in plain English for a simpleton like me!
15 Answers
...
Querying DynamoDB by date
...ndary indexes can either be global, meaning that the index spans the whole table across hash keys, or local meaning that the index would exist within each hash key partition, thus requiring the hash key to also be specified when making the query.
For the use case in this question, you would want to...
How to add border radius on table row
...
You can only apply border-radius to td, not tr or table. I've gotten around this for rounded corner tables by using these styles:
table { border-collapse: separate; }
td { border: solid 1px #000; }
tr:first-child td:first-child { border-top-left-radius: 10px; }
tr:first-ch...
How to fix “Incorrect string value” errors?
...ecting:
SET NAMES 'utf8';
SET CHARACTER SET utf8;
Next, verify that the tables where the data is stored have the utf8 character set:
SELECT
`tables`.`TABLE_NAME`,
`collations`.`character_set_name`
FROM
`information_schema`.`TABLES` AS `tables`,
`information_schema`.`COLLATION_CHARACTER_S...
PostgreSQL: insert from another table
I'm trying to insert data to a table from another table and the tables have only one column in common. The problem is, that the TABLE1 has columns that won't accept null values so I can't leave them empty and I can't get them from the TABLE2.
...
Ship an application with a database
...re database from there. This is much quicker if the database has a lot of tables and other components. Upgrades are triggered by changing the database version number in the res/values/strings.xml file. Upgrades would then be accomplished by creating a new database externally, replacing the old dat...
Simple way to transpose columns and rows in SQL?
...VOT and then an aggregate function with a CASE statement to PIVOT:
Create Table:
CREATE TABLE yourTable([color] varchar(5), [Paul] int, [John] int, [Tim] int, [Eric] int);
INSERT INTO yourTable
([color], [Paul], [John], [Tim], [Eric])
VALUES
('Red', 1, 5, 1, 3),
('Green', 8, 4, 3, 5),...
Building a notification system [closed]
...this topic is already quite old, however i'm a bit puzzled about the first table, what excactly is the purpose of this table? what is the advantage of having this as a separate table versus putting the userID in the notification_object table? In other words when will you create a new entry in notifi...