请帮忙解释VB一段代码含义（逐句）

来源：百度知道 编辑：UC知道 时间：2024/09/25 09:31:53
本人乃VB初哥，请前辈给与解释，以下为一个查询数据的代码，能给出解释吗？谢谢
Dim dbString As String
Dim db As Database
Dim rs As Recordset
Dim lstrSQL As String

lstrSQL = ""
lstrSQL = lstrSQL & "Select Count(*) as TotalCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'P', 1, null)) as PCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'C', 1, null)) as CCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'F', 1, null)) as FCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'O', 1, null)) as OCount "
lstrSQL = lstrSQL & "From Sales "
lstrSQL = lstrSQL & "Where [Employee] = '" & _
cboName.Text & "'"

dbString = App.Path & "\sales.mdb"
Set db = OpenDatabase(dbString)

' 查询
Set rs = db.OpenRecordset(lstrSQL, dbOpenSnapsho

Dim dbString As String '字符串
Dim db As Database 数据库对象
Dim rs As Recordset 表对象
Dim lstrSQL As String 查询语句字符串

lstrSQL = ""
lstrSQL = lstrSQL & "Select Count(*) as TotalCount, " 取得数量
lstrSQL = lstrSQL & "Count(iif([status] = 'P', 1, null)) as PCount, "
取得数量，如果是空为NULL，否则为1，以下同
lstrSQL = lstrSQL & "Count(iif([status] = 'C', 1, null)) as CCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'F', 1, null)) as FCount, "
lstrSQL = lstrSQL & "Count(iif([status] = 'O', 1, null)) as OCount "
lstrSQL = lstrSQL & "From Sales " 从sales表
lstrSQL = lstrSQL & "Where [Employee] = '" & _
cboName.Text & "'" 条件employee字段和coboname内容相同

dbString = App.Path & "\sales.mdb" 数据库路径
Set db = OpenDatabase(dbString) 打开数据库

' 查询
Set rs = db.OpenRecordset