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MySQL select 10 random rows from 600K rows fast
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SELECT column FROM table
ORDER BY RAND()
LIMIT 10
Not the efficient solution but works
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INSERT INTO…SELECT for all MySQL columns
...The correct syntax is described in the manual. Try this:
INSERT INTO this_table_archive (col1, col2, ..., coln)
SELECT col1, col2, ..., coln
FROM this_table
WHERE entry_date < '2011-01-01 00:00:00';
If the id columns is an auto-increment column and you already have some data in both tables the...
Oracle “(+)” Operator
..., because the ANSI-89 format (using a comma in the FROM clause to separate table references) didn't standardize OUTER joins.
The query would be re-written in ANSI-92 syntax as:
SELECT ...
FROM a
LEFT JOIN b ON b.id = a.id
This link is pretty good at explaining the difference between JOIN...
Saving timestamp in mysql table using php
I have a field in a MySQL table which has a timestamp data type. I am saving data into that table. But when I pass the timestamp ( 1299762201428 ) to the record, it automatically saves the value 0000-00-00 00:00:00 into that table.
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vertical align middle in
...s, so in that case you can wrap your text using span and than use display: table-cell; and display: table; along with vertical-align: middle;, also don't forget to use width: 100%; for #abc
Demo
#abc{
font:Verdana, Geneva, sans-serif;
font-size:18px;
text-align:left;
background-color:#0F0;...
How to list records with date from the last 10 days?
...hy don't you just try it?
The standard ANSI SQL format would be:
SELECT Table.date
FROM Table
WHERE date > current_date - interval '10' day;
I prefer that format as it makes things easier to read (but it is the same as current_date - 10).
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How to select unique records by SQL
When I perform "SELECT * FROM table" I got results like below:
8 Answers
8
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What's the best practice for primary keys in tables?
When designing tables, I've developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements:
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Center image in table td in CSS
I've been trying to align an image to the center of the table td. It worked with setting margin-left to a specific value but it also increased the size of td too and that isn't exactly what I wanted
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How to reorder data.table columns (without copying)
I'd like to reorder columns in my data.table x , given a character vector of column names, neworder :
2 Answers
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