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Kill a postgresql session/connection
...user to use this function. This works on all operating systems the same.
SELECT
pg_terminate_backend(pid)
FROM
pg_stat_activity
WHERE
-- don't kill my own connection!
pid <> pg_backend_pid()
-- don't kill the connections to other databases
AND datname = 'database...
How can I do an UPDATE statement with JOIN in SQL Server?
...oesn't support MERGE):
ANSI/ISO:
update ud
set assid = (
select sale.assid
from sale
where sale.udid = ud.id
)
where exists (
select *
from sale
where sale.udid = ud.id
);
MySQL:
update ud u
inner join sale s on
u.id = s.udid
...
What are the differences between a clustered and a non-clustered index?
...than a clustered index
Both types of index will improve performance when select data with fields that use the index but will slow down update and insert operations.
Because of the slower insert and update clustered indexes should be set on a field that is normally incremental ie Id or Timestamp.
...
add column to mysql table if it does not exist
...rade_database_1_0_to_2_0()
BEGIN
-- rename a table safely
IF NOT EXISTS( (SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA=DATABASE()
AND TABLE_NAME='my_old_table_name') ) THEN
RENAME TABLE
my_old_table_name TO my_new_table_name,
END IF;
-- add a column safely
IF NO...
View HTTP headers in Google Chrome?
...you don't see any resources - look at tabs area (All | XHR JS and etc) and select All
– Zanshin13
Jan 12 '17 at 10:05
|
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App Inventor 2 字典 vs 列表：同样存数据，性能差了10倍？ - App应用开发 ...
<font size="4"><b>App Inventor 2 字典 vs 列表：同样存数据，性能差了10倍？</b></font><br><br><br>在做 App 开发时，你可能会遇到这样一个场景：要存储一组学生信息，包含姓名、年龄、班级，然后需要快速根据姓名查到对应的班级。用列...
Selecting pandas column by location
...ed in future versions. See pandas.pydata.org/pandas-docs/dev/… on how to select by position using iloc/iat.
– Wouter Overmeire
Apr 12 '13 at 10:04
1
...
Jdbctemplate query for string: EmptyResultDataAccessException: Incorrect result size: expected 1, ac
...ce is you call ResultSet.next().
public String test() {
String sql = "select ID_NMB_SRZ from codb_owner.TR_LTM_SLS_RTN "
+ " where id_str_rt = '999' and ID_NMB_SRZ = '60230009999999'";
return jdbc.query(sql, new ResultSetExtractor<String>() {
@Override
...
Convert Linq Query Result to Dictionary
... @pawan - that doesn't look right. I'd expect var servers = list.Select( s => new { s.ProjectName, Url = "tcp://" + s.BuildMachineName + ":" + s.PortNumber + "/CruiseManager.rem" } ).ToDictionary( s => s.ProjectName, s.Url ); This creates a dictionary keyed by project name of projec...
Visual Studio: How to break on handled exceptions?
...the VS2010 environement, by going to "Tools", "Import Export Settings" and select a reset to the C# environment... it contains the Exceptions Submenu item
– BeardinaSuit
Feb 14 '12 at 16:28
...