大约有 40,000 项符合查询结果（耗时：0.0369秒） [XML]
PostgreSQL database default location on Linux
...ry that is the DB? because I was thinking in something like the DB file on mysql or sql server for example...
– CamiloVA
Mar 26 at 4:33
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Delete all data in SQL Server database
...stem stored procs */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)
SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'P' AND category = 0 ORDER BY [name])
WHILE @name is not null
BEGIN
SELECT @SQL = 'DROP PROCEDURE [dbo].[' + RTRIM(@name) +']'
EXEC (@SQL)
PRINT ...
How to execute a raw update sql with dynamic binding in rails
...ch less efficient, isn't it. Doesn't this trade one update statement for a select, bring the records into rails memory, update each record and send an update statement back for each record. 1 update vs 1 per record and much bandwidth, etc.? Does AR optimize this or not? I don't think it does.
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update columns values with column of another table based on condition [duplicate]
...ble1.id = table2.id
You can also try this:
UPDATE table1
SET price=(SELECT price FROM table2 WHERE table1.id=table2.id);
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SQL: How to perform string does not equal
...
Try the following query
select * from table
where NOT (tester = 'username')
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What are the disadvantages of using persistent connection in PDO
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I hope I had read this answer before running SELECT orders.* FROM orders LEFT JOIN items USING(item_id)
– Ast Derek
Jul 26 '10 at 18:09
31
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Add Keypair to existing EC2 instance
...editing, or copying files that belong to non-root users. For example, your mysql user on instance A may have the same UID as your postfix user on instance B which could cause problems if you chown files with one name and then move the volume back to A.
Wrap Up
After you are done and you are happy ...
Condition within JOIN or WHERE
...of filtering criteria more easily maintainable.
For example, instead of:
SELECT *
FROM Customers c
INNER JOIN CustomerAccounts ca
ON ca.CustomerID = c.CustomerID
AND c.State = 'NY'
INNER JOIN Accounts a
ON ca.AccountID = a.AccountID
AND a.Status = 1
Write:
SELECT *
FROM Customer...
Cannot issue data manipulation statements with executeQuery()
...() to issue data manipulation statements. executeQuery() is only meant for SELECT queries (i.e. queries that return a result set).
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【BLE技术内幕】BLE技术揭秘 - 创客硬件开发 - 清泛IT论坛，有思想、有深度
...个时间点把数据包发送出去，怎么保证数据的完整性，ACK如何接收，如何进行重传，以及如何对链路进行管理和控制等等。LL层只负责把数据发出去或者收回来，对数据进行怎样的解析则交给上面的GAP或者ATTHost Controller Interface，...