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SQLAlchemy - Getting a list of tables
...te_engine('postgresql+psycopg2://root:password@localhost/
q = eng.execute('SELECT * FROM pg_catalog.pg_tables')
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SQL is null and = null [duplicate]
...e t (x int, y int);
insert into t values (null, null), (null, 1), (1, 1);
select 'x = null' as test , x, y from t where x = null
union all
select 'x != null', x, y from t where x != null
union all
select 'not (x = null)', x, y from t where not (x = null)
union all
select 'x = y', x, y from t where ...
MySQL: Enable LOAD DATA LOCAL INFILE
I'm running Mysql 5.5 on Ubuntu 12 LTS. How should I enable LOAD DATA LOCAL INFILE in my.cnf?
18 Answers
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When to use Common Table Expression (CTE)
...ing well? Can someone give me a simple example of limitations with regular select, derived or temp table queries to make the case of CTE? Any simple examples would be highly appreciated.
...
Purpose of Unions in C and C++
... @legends2k: any decent optimizer will recognize bitwise operations that select an entire byte and generate code to read/write the byte, same as the union but well-defined (and portable). e.g. uint8_t getRed() const { return colour & 0x000000FF; } void setRed(uint8_t r) { colour = (colour &...
常用Git命令汇总 - 开源 & Github - 清泛网 - 专注C/C++及内核技术
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#改变暂存区的修改（其实是重置HEAD，将指定版本库的内容状态去覆盖暂存区，从而达到暂存区的改变）
git reset <file> #从暂存区恢复到工作区（不指定版本id，则默认为最后一次提交的版本id）
git r...
How to export a mysql database using Command Prompt?
...ves error "mysqldump: Got error: 1049: Unknown database 'thepassword' when selecting the database" but worked when i delete "-p userpassword"
– Ateş Danış
Jul 7 '13 at 6:35
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how to check and set max_allowed_packet mysql variable [duplicate]
...ass', 'dbname' );
// to get the max_allowed_packet
$maxp = $db->query( 'SELECT @@global.max_allowed_packet' )->fetch_array();
echo $maxp[ 0 ];
// to set the max_allowed_packet to 500MB
$db->query( 'SET @@global.max_allowed_packet = ' . 500 * 1024 * 1024 );
So if you've got a query you exp...
What is the difference/usage of homebrew, macports or other package installation tools? [closed]
...to do the same with Homebrew.
MacPorts support groups.
foo@macpro:~/ port select --summary
Name Selected Options
==== ======== =======
db none db46 none
gcc none gcc42 llvm-gcc42 mp-gcc48 none
llvm none mp-llvm-3.3 none
mys...
How to change identity column values programmatically?
...ITY(1,1) PRIMARY KEY,
X VARCHAR(10)
)
INSERT INTO Test
OUTPUT INSERTED.*
SELECT 'Foo' UNION ALL
SELECT 'Bar' UNION ALL
SELECT 'Baz'
Then you can do
/*Define table with same structure but no IDENTITY*/
CREATE TABLE Temp
(
ID INT PRIMARY KEY,
X VARCHAR(10)
)
/*Switch table metadata to new struct...