我在SQL Server中有一个表,如下所示:
Table1:
Id Symbol
1 a
5 c
8 d
3 b
我想排序基于数据Id并连接symbol在连续行:
Query Result:
Id Symbol
1 ab
3 bc
5 cd
8 d
什么是这个结果的最佳查询？
[Raw data]
A B C
1 10 1
1 10 2
2 20 3
2 20 4
1 100 5
1 100 6
[Wanted result]
A SUM_OF_B
1 20
2 40
1 200
查询具有简单的'group by'子句和'dense_rank over partition by'是不可用的,因为分组可以处理所有行.但是我想要在订购状态下进行分组.如何编写正确的查询？
我redim在VBA Excel中使用函数保留有一些问题.
我想要redim一个我已经在宏中使用的数组,而不清楚已经存在的数据.
我的宏看起来像这样:
Dim table_data As Variant
...
ReDim table_data(2 * n + 2 * m + 2 * n, table_case.ListColumns.Count - 1)
...
dim1 = UBound(table_data, 1)
dim2 = UBound(table_data, 2)
ReDim Preserve table_data(0 To dim1 + 2 * n, 0 To dim2)
你知道我应该修改什么吗？
出于某种原因,我使用MongoDB本机ObjectId作为我的应用程序的票证识别号码的主键.是否可以使用ObjectId部件搜索文档？
例如:我有文件:
[
{_id: ObjectId("577f8e6537e4a676203c056a")},
{_id: ObjectId("577f8ee437e4a676203c0577")},
{_id: ObjectId("577f8f3d717b6fdd22a1684c")}
]
我想查询它_id包含"0577",以便它返回
{_id: ObjectId("577f8ee437e4a676203c0577")}
我之前尝试过正则表达式.它回来了[]
db.transaction.find({_id: /0577/i}) ---> return 0
db.transaction.find({_id: {$regex: /0577/, $options: "i"}}) ---> return 0
任何人都可以帮助创建一个带有uuid生成器字段的列，该列会在插入行时自动生成随机数。
有谁知道如何返回数据库名称？我似乎不知道如何sys.database_files加入sys.databases。
SELECT
a.NAME as FileName,
FG.name as FileGroup,
a.physical_name as FilePath,
a.type_desc as FileType,
CONVERT(DECIMAL(12,2),ROUND(a.size/128.000,2)) AS [Size],
CONVERT(DECIMAL(12,2),ROUND(FILEPROPERTY(a.name,'SpaceUsed')/128.000,2)) AS [Used] ,
CONVERT(DECIMAL(12,2),ROUND((a.size-FILEPROPERTY(a.name,'SpaceUsed'))/128.000,2)) AS [Free]
FROM
sys.database_files a
LEFT JOIN sys.filegroups FG ON
FG.data_space_id = a.data_space_id
我有一个名为的数组Buffer.我正在使用for循环将其内容初始化为0.我如何在C#中的单个语句中执行此操作？我不想使用for循环.
byte[] Buffer = new byte[50];
int arrC = 0;
// array initialization
for (arrC = 0; arrC < 50; arrC++)
{
Buffer[arrC] = 0;
}
我正在使用SQL Server 2008.
我想将记录插入到表中ExecuteNonQuery,为此我写了:
customUtility.ExecuteNonQuery("insert into furniture_ProductAccessories(Product_id, Accessories_id, SkuNo, Description1, Price, Discount) values(" + prodid + "," + strAcc + "," + txtSKUNo.Text + "," + txtAccDesc.Text + "," + txtAccPrices.Text + "," + txtAccDiscount.Text + ")");
以下是ExecuteNonQuery功能:
public static bool ExecuteNonQuery(string SQL)
{
bool retVal = false;
using (SqlConnection con = new SqlConnection(System.Web.Configuration.WebConfigurationManager.ConnectionStrings["dbConnect"].ToString()))
{
con.Open();
SqlTransaction trans = con.BeginTransaction();
SqlCommand command = new SqlCommand(SQL, con, trans);
try
{
command.ExecuteNonQuery();
trans.Commit();
retVal = true;
}
catch(Exception …我已经在这几个小时了,不能休息一下.我正在用C#编写这个程序,它连接到数据库并在每次有新的传感器读数时写入新的行.将新行写入DB的Function片段如下所示.
当我运行我的代码时,我继续得到以下运行时错误:
System.Data.SqlClient.SqlException(0x80131904):必须声明标量变量"@dbSpeed".
当我从使用常规旧数组切换到Dictionary时,我开始遇到这个问题,但我不确定是什么原因.
private void WriteDataRowtoSQL(Dictionary<string, double> dataPoints)
{
//SQL Database Connection String.
string dataSource = @"Data Source=TSCRPC\TSCRPCDB;Initial Catalog=TSCRPCDB;Integrated Security=True";
//SQL Database Query Command Build to insert sensor data as rows.
string sensorDataRowItems = "(Date,Time,Mac_State,S_GainStatus,S_Speed,S_Direction,S_Temperature,S_Humidity,S_PowerOutput,S_Current,S_Voltage,S_EngineRPM,S_NoiseLevel,S_BatteryVolts,S_TorkStrain1,S_TorkStrain2,S_WheelStrain,S_Vibration1,S_Vibration2,S_BreakPressure)";
string cmdString = "INSERT INTO SensorData " + sensorDataRowItems + " VALUES (@dbDate, @dbTime, @dbMacState, @dbGainStatus, @dbSpeed, @dbDirection, @dbTemperature, @dbHumidity, @dbPowerOutput, @dbCurrent, @dbVoltage, @dbEngineRPM, @dbNoiseLevel, @dbBatteryVolts, @dbTorkStrain1, @dbTorkStrain2, @dbWheelStrain, @dbVibration1, @dbVibration2, @dbBreakPressure)";
//Connect to and use SQL DB.
using (SqlConnection sqlConn = new SqlConnection(dataSource)) …我正在尝试制作一个记录用户点击内容的宏，然后记录鼠标坐标和点击之间的延迟。这将在一些其他SendKey更改后重复。如何检测宏运行时单击鼠标的时间？我已经知道如何获取坐标并记录延迟，但是检测鼠标点击的最佳方法是什么，以及保存所有这些信息的最佳方法是什么？一个文本文件？这是我使用的鼠标单击事件的片段：
Public Declare Function SetCursorPos Lib "user32" (ByVal x As Long, ByVal y As Long) As Long
Public Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Public Type POINTAPI
x As Long
y As Long
End Type
Public pos As POINTAPI ' Declare variable
Public Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Long, ByVal dx As Long, ByVal dy As Long, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
Public Const MOUSEEVENTF_LEFTDOWN = &H2
Public …