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MySQL error: key specification without a key length
...d, and the trick is to choose a number N that’s long enough to give good selectivity, but short enough to save space. The prefix should be long enough to make the index nearly as useful as it would be if you’d indexed the whole column.
Before we go further let us define some important terms. In...
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...
Remove leading or trailing spaces in an entire column of data
...HAR(160) directly without a workaround formula by
Edit .... Replace your selected data,
in Find What hold ALT and type 0160 using the numeric keypad
Leave Replace With as blank and select Replace All
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Most efficient T-SQL way to pad a varchar on the left to a certain length?
...cely. It will also perform the conversion for you:
declare @n as int = 2
select FORMAT(@n, 'd10') as padWithZeros
Update:
I wanted to test the actual efficiency of the FORMAT function myself. I was quite surprised to find the efficiency was not very good compared to the original answer from Al...
How to get a date in YYYY-MM-DD format from a TSQL datetime field?
...
SELECT CONVERT(char(10), GetDate(),126)
Limiting the size of the varchar chops of the hour portion that you don't want.
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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...
Generate random password string with requirements in javascript
...ough bits to "fill up" the full decimal space, the last digit will only be selected from a certain set of values. For example, on my computer, the last digit is only ever "i", "r", and "9". Use this instead: Math.random().toString(36).substr(2, 8)
– Joel
Jan 19...
How do I turn off Oracle password expiration?
...rtain user profile in Oracle first check which profile the user is using:
select profile from DBA_USERS where username = '<username>';
Then you can change the limit to never expire using:
alter profile <profile_name> limit password_life_time UNLIMITED;
If you want to previously che...
How does database indexing work? [closed]
...arising from the file systems size limits, careful thought must be used to select the correct fields to index.
Since indices are only used to speed up the searching for a matching field within the records, it stands to reason that indexing fields used only for output would be simply a waste of disk...
How do I get the size of a java.sql.ResultSet?
...
Do a SELECT COUNT(*) FROM ... query instead.
OR
int size =0;
if (rs != null)
{
rs.last(); // moves cursor to the last row
size = rs.getRow(); // get row id
}
In either of the case, you won't have to loop over the enti...