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Join vs. sub-query
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@JinghuiNiu Customers who bought expensive items: select custid from cust join bought using (custid) where price > 500. If a customer bought multiple expensive items, you'll get double-ups. To fix this, select custid from cust where exists (select * from bought where cust...
In MySQL, can I copy one row to insert into the same table?
...e) but I want to do this without having to list all the columns after the "select", because this table has too many columns.
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How to select bottom most rows?
I can do SELECT TOP (200) ... but why not BOTTOM (200)?
14 Answers
14
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Create table (structure) from existing table
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Try:
Select * Into <DestinationTableName> From <SourceTableName> Where 1 = 2
Note that this will not copy indexes, keys, etc.
If you want to copy the entire structure, you need to generate a Create Script of the tab...
Programmatically selecting text in an input field on iOS devices (mobile Safari)
How do you programmatically select the text of an input field on iOS devices, e.g. iPhone, iPad running mobile Safari?
10 A...
How to declare a variable in a PostgreSQL query
...ows you to return a table of temporary values.
WITH master_user AS (
SELECT
login,
registration_date
FROM users
WHERE ...
)
SELECT *
FROM users
WHERE master_login = (SELECT login
FROM master_user)
AND (SELECT registration_date
FROM ma...
How to concatenate columns in a Postgres SELECT?
... an explicit coercion to text [...]
Bold emphasis mine. The 2nd example (select a||', '||b from foo) works for any data types since the untyped string literal ', ' defaults to type text making the whole expression valid in any case.
For non-string data types, you can "fix" the 1st statement by c...
Get table names using SELECT statement in MySQL
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To get the name of all tables use:
SELECT table_name FROM information_schema.tables;
To get the name of the tables from a specific database use:
SELECT table_name FROM information_schema.tables
WHERE table_schema = 'your_database_name';
Now, to answer the...
jQuery get value of select onChange
I was under the impression that I could get the value of a select input by doing this $(this).val(); and applying the onchange parameter to the select field.
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'IF' in 'SELECT' statement - choose output value based on column values
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SELECT id,
IF(type = 'P', amount, amount * -1) as amount
FROM report
See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of...