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Database development mistakes made by application developers [closed]
... auto-incrementing fields (SQL Server, MySQL, others) or sequences (most notably Oracle).
In my opinion you should always use surrogate keys. This issue has come up in these questions:
How do you like your primary keys?
What's the best practice for primary keys in tables?
Which format of primary...
How can I test a Windows DLL file to determine if it is 32 bit or 64 bit? [duplicate]
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Gory details
A DLL uses the PE executable format, and it's not too tricky to read that information out of the file.
See this MSDN article on the PE File Format for an overview. You need to read the MS-DOS header, then read the IMAGE_NT_HEADERS structure. This ...
Ruby on Rails generates model field:type - what are the options for field:type?
...tetime, :timestamp,
:time, :date, :binary, :boolean, :references
See the table definitions section.
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Laravel Eloquent: How to get only certain columns from joined tables
I have got 2 joined tables in Eloquent namely themes and users.
15 Answers
15
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Rails: FATAL - Peer authentication failed for user (PG::Error)
...tly by creating a database and assigning ownership to your app's user to establish the connection. To create a new user in postgresql 9 run:
sudo -u postgres psql
set the postgresql user password if you haven't, it's just backslash password.
postgres=# \password
Create a new user and password ...
How to atomically delete keys matching a pattern using Redis
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Lua's unpack transforms a table in a "list of independent variables" (other languages call that explode) but the max number is not dependent on the syste memory; it's fixed in lua through the LUAI_MAXSTACK constant. In Lua 5.1 & LuaJIT it's 8000 a...
How do I flush the PRINT buffer in TSQL?
... on PRINT or RAISERROR and just load your "print" statements into a ##Temp table in TempDB or a permanent table in your database which will give you visibility to the data immediately via a SELECT statement from another window. This works the best for me. Using a permanent table then also serves a...
MySQL: Large VARCHAR vs. TEXT?
I've got a messages table in MySQL which records messages between users. Apart from the typical ids and message types (all integer types) I need to save the actual message text as either VARCHAR or TEXT. I'm setting a front-end limit of 3000 characters which means the messages would never be inserte...
How to place div side by side
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Using CSS display property - which can be used to make divs act like a table:
<div style="width: 100%; display: table;">
<div style="display: table-row">
<div style="width: 600px; display: table-cell;"> Left </div>
<div style="display: table-ce...
Performance of FOR vs FOREACH in PHP
..._arr1 = array();
$test_arr2 = array();
$test_arr3 = array();
// hash tables
$test_arr4 = array();
$test_arr5 = array();
for ($i = 0; $i < $test_arr_size; ++$i)
{
mt_srand();
$hash = md5(mt_rand());
$key = substr($hash, 0, 5).$i;
$test_arr1[$i] = $test_arr2[$i] = $t...