大约有 47,000 项符合查询结果（耗时：0.0429秒） [XML]
What is the difference between ExecuteScalar, ExecuteReader and ExecuteNonQuery?
... then the result is the first column of the first row. An example might be SELECT @@IDENTITY AS 'Identity'.
ExecuteReader is used for any result set with multiple rows/columns (e.g., SELECT col1, col2 from sometable).
ExecuteNonQuery is typically used for SQL statements without results (e.g., UPDATE...
How can I convert a hex string to a byte array? [duplicate]
...gth)
.Where(x => x % 2 == 0)
.Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
.ToArray();
}
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Rails find record with zero has_many records associated [duplicate]
..._joins(:photos).where(photos: {id: nil})
which will result in SQL like:
SELECT cities.*
FROM cities LEFT OUTER JOIN photos ON photos.city_id = city.id
WHERE photos.id IS NULL
Using includes:
City.includes(:photos).where(photos: {id: nil})
will have the same result, but will result in much ug...
How to find server name of SQL Server Management Studio
...
Run this Query to get the name
SELECT @@SERVERNAME
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Renaming projects in Xcode 4
...matically change all project-name-related entries and will allow you to de-select some of them if you want.
Nice.
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MySql export schema without data
...e the view definition. So if yo had a view like following
create view v1
select `a`.`id` AS `id`,
`a`.`created_date` AS `created_date`
from t1;
with --no-data option, view definition will get changed to following
create view v1
select 1 AS `id`, 1 AS `created_date`
...
How to execute IN() SQL queries with Spring's JDBCTemplate effectivly?
...ters.addValue("ids", ids);
List<Foo> foo = getJdbcTemplate().query("SELECT * FROM foo WHERE a IN (:ids)",
parameters, getRowMapper());
This only works if getJdbcTemplate() returns an instance of type NamedParameterJdbcTemplate
...
Case conventions on element names?
...inent examples:
<a>1</a><b>1</b>
<xsl:value-of select="a+b"/>
outputs 2, as expected
<a>1</a><b>1</b>
<xsl:value-of select="a-b"/>
DOES NOT ERROR, BUT OUTPUTS NOTHING AT ALL
In the above code, you must put at least one space before a su...
How to import an excel file in to a MySQL database
...r Excel table into the sales table of a MySQL database named mydatabase.
Select the relevant cells:
Paste into Mr. Data Converter and select the output as MySQL:
Change the table name and column definitions to fit your requirements in the generated output:
CREATE TABLE sales (
id INT NOT N...
Convert List into Comma-Separated String
...s before you Aggragate to string. So you can do something like this: list.Select(x => string.Format("{0}:{1}", x.Key, x.Value)).Aggregate((a, x) => a+ ", " + x);
– bets
Jul 20 '17 at 8:14
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