update
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英语单词，主要用作为动词、名词，作动词时译为“更新；校正，修正；使现代化”；作名词时译为“更新；现代化”。
词 性：动词、名词
英式读音[ˌʌpˈdeɪt]
美式读音[ˌʌpˈdeɪt]
单词用法
V-T/V-I If you update something, you make it more modern, usually by adding new parts to it or giving new information. 更新
N-COUNT An update is a news item containing the latest information about a particular situation. 最新消息; 快讯
V-T If you update someone on a situation, you tell them the latest developments in that situation. 给…提供最新信息
词组短语
update information 更新信息；修正信息
dynamic update 动态更新；动态升级
last update 最新更新
update now 立即更新
双语例句
He was back in the office, updating the work schedule on the computer.
他回到办公室，在计算机上更新了工作日程。
Airlines would prefer to update rather than retrain crews.
航空公司宁愿增添新机组人员而不愿对老的机组人员进行再培训。
She had heard the newsflash on a TV channel's news update.
她在电视频道的新闻快讯里听到了这条简短报道。
We'll update you on the day's top news stories.
我们将向你提供当天的头条新闻。
update
（数据库SQL语法用语）
Update是一个数据库SQL语法用语，用途是更新表中原有数据，单独使用时使用where匹配字段。
外文名Update
性 质：数据库SQL语法用语
用 途：更新表中原有数据
单独使用：使用where匹配字段
update概述
用途：更新表中原有数据
单独使用，使用where匹配字段
set后面，更新字段值，既可以一次一项，也可以一次多项
例如1，
Update table_name Set column_name = new_value Where column_name = some_value
例：
“Person”表中的原始数据:
LastName FirstName Address City
Nilsen Fred Kirkegt 56 Stavanger
Rasmussen Storgt 67
运行下面的SQL将Person表中LastName字段为”Rasmussen”的FirstName更新为”Nina”：
UPDATE Person SET FirstName = 'Nina' WHERE LastName = 'Rasmussen'
更新后”Person”表中的数据为：
LastName FirstName Address City
Nilsen Fred Kirkegt 56 Stavanger
Rasmussen Nina Storgt 67
同样的，用UPDATE语句也可以同时更新多个字段：
例如2，
UPDATE Person SET Address = 'Stien 12', City = 'Stavanger' WHERE LastName = 'Rasmussen'
更新后”Person”表中的数据为：
LastName FirstName Address City
Nilsen Fred Kirkegt 56 Stavanger
Rasmussen Nina Stien 12 Stavanger
update语法
UPDATE 表名称 SET 列名称 = 新值 WHERE 列名称 = 某值 [1]
?
请点击输入图片描述
1.UPDATE table_name2.SET column1=value1,column2=value2,...3.WHERE column(1)=value(1),column(2)=value(2)...and column(n)=value(n);
详情请参考百度百科：
网页链接
西门子：WinTcpS7,三菱：EntQsPlc,欧姆龙：FinsTCP，百度都能搜到资源的；
提供一个VB.NET与OMRON以太网通讯的代码，是我项目里面复制出来的：
Dim Handle1 As Int32 'PLC的连接句柄
Dim EntLink As Boolean '连接标志
Dim PLC As New FinsTcp.PlcClient '引用OMRON的通讯组件
Private Sub butLink_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butLink.Click
Dim re As Short
Dim restr As String = ""
re = PLC.EntLink(Trim(txtLocalIP.Text), Val(txtLocalPort.Text), Trim(txtRemoteIP.Text), Val(txtRemotePort.Text), "DEMO", Handle1)
txtReLink.Text = re.ToString
If re = 0 Then
EntLink = True
MsgBox("PLC联接成功! ")
Else
EntLink = False
MsgBox("PLC联接失败: " restr)
End If
End Sub
Private Sub butClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butClose.Click
Dim re As Short
EntLink = False
re = PLC.DeLink(Handle1)
txtReClose.Text = re.ToString
End Sub
Private Sub butRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butRead.Click
Dim re As Short
Dim i As Short
Dim RD() As Object
ReDim RD(Val(txtReadCnt.Text - 1))
If Not EntLink Then
MsgBox("还未与PLC建立联接！")
Exit Sub
End If
Dim mry As FinsTcp.PlcClient.PlcMemory = cmbReadMry.SelectedIndex + 1
Dim typ As FinsTcp.PlcClient.DataType = cmbReadType.SelectedIndex + 1
re = PLC.CmdRead(Handle1, mry, typ, CUShort(Val(txtReadAdd.Text)), CUShort(Val(txtReadCnt.Text)), RD)
txtReRead.Text = re.ToString
lstRead.Items.Clear()
For i = 0 To UBound(RD) Step 1
If Not IsNothing(RD(i)) Then lstRead.Items.Add(RD(i))
Next i
If re 0 Then
Timer1.Enabled = False
butScan.Text = "Cycle R/W"
End If
End Sub
Private Sub butWrite_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butWrite.Click
Dim re As Short
Dim i As Short
Dim temp() As String
Dim WD() As Object
If Not EntLink Then
MsgBox("还未与PLC建立联接！")
Exit Sub
End If
ReDim WD(Val(txtWriteCnt.Text) - 1)
temp = Split(txtWrite.Text, vbCrLf)
For i = 0 To UBound(WD) Step 1
If i UBound(temp) Then
WD(i) = 0
Else
WD(i) = Trim(temp(i))
End If
Next i
Dim mry As FinsTcp.PlcClient.PlcMemory = cmbWriteMry.SelectedIndex + 1
Dim typ As FinsTcp.PlcClient.DataType = cmbWriteType.SelectedIndex + 1
re = PLC.CmdWrite(Handle1, mry, typ, CUShort(Val(txtWriteAdd.Text)), CUShort(Val(txtWriteCnt.Text)), WD)
txtReWrite.Text = re.ToString
If re 0 Then
Timer1.Enabled = False
butScan.Text = "Cycle R/W"
End If
End Sub
