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Binary Data in MySQL [closed]
... mysql_connect("localhost", "root", "password");
mysql_select_db("binary_data");
$data = mysql_real_escape_string(fread(fopen($form_data, "r"), filesize($form_data)));
$result = mysql_query("INSERT INTO binary_data (description, bin_data, filenam...
Modify table: How to change 'Allow Nulls' attribute from not null to allow null
...
I wrote this so I could edit all tables and columns to null at once:
select
case
when sc.max_length = '-1' and st.name in ('char','decimal','nvarchar','varchar')
then
'alter table [' + so.name + '] alter column [' + sc.name + '] ' + st.name + '(MAX) NULL'
when st.name in ('char','decimal','n...
Importance of varchar length in MySQL table
...
Anytime your select query uses a temporary table (group and order by operations, among other things) it will convert varchar(200) to a char(200) and performance will suffer.
– Jamie
Feb 7 '13 at 20:1...
Using printf with a non-null terminated string
...rray is null-terminated, it just treats it as a longer array that it's sub-selecting from - which means that if you have a string with nulls in it, this will cause problems.
– lahwran
Mar 16 '16 at 0:39
...
SQL Server indexes - ascending or descending, what difference does it make?
...TE INDEX ix_index ON mytable (col1, col2 DESC);
can be used for either:
SELECT *
FROM mytable
ORDER BY
col1, col2 DESC
or:
SELECT *
FROM mytable
ORDER BY
col1 DESC, col2
, but not for:
SELECT *
FROM mytable
ORDER BY
col1, col2
An index on a single colum...
How To Test if Type is Primitive
...
where t.IsValueType
select typeof (Nullable<>).MakeGenericType(t);
List = types.Concat(nullTypes).ToArray();
}
public static bool Test(Type type)
{
if (List.Any(x => x.IsAssignableFrom(type))...
Auto increment primary key in SQL Server Management Studio 2012
...h non-zero scale) and ofc, the identity spec should be compatible with the selected data type.
– Pred
Feb 4 '15 at 14:36
...
How to use NULL or empty string in SQL
...
Select *
From Table
Where (col is null or col = '')
Or
Select *
From Table
Where IsNull(col, '') = ''
share
|
improve t...
Storing Data in MySQL as JSON
... statement, including WHERE, ORDER BY, and GROUP BY clauses. This includes SELECT, UPDATE, DELETE, CREATE TABLE, and other SQL statements. The left hand side must be a JSON column identifier (and not an alias). The right hand side is a quoted JSON path expression which is evaluated against the JSON ...
LR性能指标解释 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...。
4.JMap。监控java程序是否有内存泄漏，需要配合eclipse插件或者MemoryAnalyzer来使用。
5.JProfiler。全面监控每个节点的CPU使用率、内存使用率、响应时间累计值、线程执行情况等，需要在JVM参数中进行配置。
6.Nmon。全面监控linux...