大约有 47,000 项符合查询结果（耗时：0.0265秒） [XML]
How can I disable the UITableView selection?
When you tap a row in a UITableView , the row is highlighted and selected. Is it possible to disable this so tapping a row does nothing?
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Detect if value is number in MySQL
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This should work in most cases.
SELECT * FROM myTable WHERE concat('',col1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
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Using $_POST to get select option value from HTML
I use select as below:
8 Answers
8
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SQL: How to properly check if a record exists
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It's better to use either of the following:
-- Method 1.
SELECT 1
FROM table_name
WHERE unique_key = value;
-- Method 2.
SELECT COUNT(1)
FROM table_name
WHERE unique_key = value;
The first alternative should give you no result or one result, the second count should be zero or on...
Oracle SQL Query for listing all Schemas in a DB
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Using sqlplus
sqlplus / as sysdba
run:
SELECT *
FROM dba_users
Should you only want the usernames do the following:
SELECT username
FROM dba_users
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how do I query sql for a latest record date for each user
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select t.username, t.date, t.value
from MyTable t
inner join (
select username, max(date) as MaxDate
from MyTable
group by username
) tm on t.username = tm.username and t.date = tm.MaxDate
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Difference between Select and ConvertAll in C#
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Select is a LINQ extension method and works on all IEnumerable<T> objects whereas ConvertAll is implemented only by List<T>. The ConvertAll method exists since .NET 2.0 whereas LINQ was introduced with 3.5.
You s...
Finding duplicate values in a SQL table
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SELECT
name, email, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY ...
Selecting element by data attribute
Is there an easy and straight-forward method to select elements based on their data attribute? For example, select all anchors that has data attribute named customerID which has value of 22 .
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Find rows that have the same value on a column in MySQL
...sses and how many times they're used, with the most used addresses first.
SELECT email,
count(*) AS c
FROM TABLE
GROUP BY email
HAVING c > 1
ORDER BY c DESC
If you want the full rows:
select * from table where email in (
select email from table
group by email having count(*) &g...