链式 CURD - 聚合终结方法

聚合方法直接返回计算结果，无需手动构建 SELECT COUNT(*) FROM ...。详细架构参见 链式 CURD 概述。

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RowCount - 统计行数

语法

Function RowCount() As Long

示例

' 统计总行数
Dim total As Long
total = db.Table("users").RowCount

' 条件统计
Dim activeCount As Long
activeCount = db.Table("users").Where("status=?", "active").RowCount

' 范围统计
Dim youngCount As Long
youngCount = db.Table("users").WhereBetween("age", 18, 30).RowCount

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RowExists - 判断是否存在

语法

Function RowExists() As Boolean

示例

' 判断用户是否存在
If db.Table("users").Where("serial_no=?", sn).RowExists Then
    MsgBox "设备已存在"
Else
    MsgBox "设备不存在"
End If

' 判断邮箱是否已注册
If db.Table("users").Where("email=?", email).RowExists Then
    MsgBox "邮箱已注册"
End If

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RowPluck - 提取单列值列表

返回 Collection，包含指定字段的所有值。

语法

Function RowPluck(ByVal FieldName As String) As Collection

示例

' 提取所有用户名
Dim names As Collection
Set names = db.Table("users").RowPluck("name")

' 提取满足条件的ID列表
Dim ids As Collection
Set ids = db.Table("users").Where("role=?", "admin").RowPluck("id")

' 遍历提取结果
Dim v As Variant
For Each v In ids
    Debug.Print "管理员ID: " & v
Next

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RowMax - 最大值

语法

Function RowMax(ByVal FieldName As String) As Variant

示例

Dim maxAge As Variant
maxAge = db.Table("users").RowMax("age")
Debug.Print "最大年龄: " & maxAge

' 条件最大值
Dim maxSalary As Variant
maxSalary = db.Table("users").Where("dept=?", "IT").RowMax("salary")

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RowMin - 最小值

Dim minAge As Variant
minAge = db.Table("users").RowMin("age")

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RowSum - 求和

Dim totalAmount As Variant
totalAmount = db.Table("orders").Where("year=?", 2026).RowSum("amount")
Debug.Print "2026年总金额: " & totalAmount

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RowAvg - 平均值

Dim avgSalary As Variant
avgSalary = db.Table("users").Where("dept=?", "IT").RowAvg("salary")
Debug.Print "IT部门平均薪资: " & avgSalary

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最后更新: 2026-06-26