大约有 3,568 项符合查询结果（耗时：0.0171秒） [XML]
How to establish a connection pool in JDBC?
...ource cpds = new ComboPooledDataSource();
cpds.setDriverClass( "org.postgresql.Driver" ); //loads the jdbc driver
cpds.setJdbcUrl( "jdbc:postgresql://localhost/testdb" );
cpds.setUser("swaldman");
cpds.setPassword("test-password");
// the settings below are optional -- c3p0 can work with defaults
c...
Exit single-user mode
...the processes that have been currently running.
Then, run the following T-SQL to set the database in MULTI_USER mode.
USE master
GO
DECLARE @kill varchar(max) = '';
SELECT @kill = @kill + 'KILL ' + CONVERT(varchar(10), spid) + '; '
FROM master..sysprocesses
WHERE spid > 50 AND dbid = DB_ID('&l...
Store pictures as files or in the database for a web app?
...
Also, in SQL Server when you store the image as an "Image" field, this is effectively what SQL is doing - storing a pointer to the file on disk somewhere. This is how it gets around the 8KB page limit.
– Zhaph - ...
MySQL stored procedure vs function, which would I use when?
I'm looking at MySQL stored procedures and function. What is the real difference?
5 Answers
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PostgreSQL Crosstab Query
Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
6 Answers
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Store query result in a variable using in PL/pgSQL
How to assign the result of a query to a variable in PL/pgSQL, the procedural language of PostgreSQL?
5 Answers
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IN clause and placeholders
I'm attempting to do the following SQL query within Android:
9 Answers
9
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Are there any disadvantages to always using nvarchar(MAX)?
In SQL Server 2005, are there any disadvantages to making all character fields nvarchar(MAX) rather than specifying a length explicitly, e.g. nvarchar(255)? (Apart from the obvious one that you aren't able to limit the field length at the database level)
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Max return value if empty query
...on the result. I also think (I haven't tested this yet) that the generated SQL would use an extra subselect query by doing that, while mine would just deal with an empty set by returning null. Thanks for the upvote and feedback! ;)
– CptRobby
Nov 22 '16 at 14:3...
How do I check if an index exists on a table field in MySQL?
...Use SHOW INDEX like so:
SHOW INDEX FROM [tablename]
Docs: https://dev.mysql.com/doc/refman/5.0/en/show-index.html
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