初始化

2025-12-11 14:07:27 +08:00
commit 6c5f82686c
219 changed files with 332473 additions and 0 deletions
--- a/Database/Base/TriggerBuilder.vb
+++ b/Database/Base/TriggerBuilder.vb
@@ -0,0 +1,71 @@
+Imports System.Collections.Generic
+Imports System.Text
+
+Namespace Database.Base
+
+    Public Module TriggerBuilder
+        Public Function GetForeignKeyTriggers(ByVal dt As TableSchema) As IList(Of TriggerSchema)
+            Dim result As IList(Of TriggerSchema) = New List(Of TriggerSchema)()
+            For Each fks As ForeignKeySchema In dt.ForeignKeys
+                result.Add(GenerateInsertTrigger(fks))
+                result.Add(GenerateUpdateTrigger(fks))
+                result.Add(GenerateDeleteTrigger(fks))
+            Next
+            Return result
+        End Function
+
+        Private Function MakeTriggerName(ByVal fks As ForeignKeySchema, ByVal prefix As String) As String
+            Return prefix & "_" & fks.TableName & "_" & fks.ColumnName & "_" & fks.ForeignTableName & "_" & fks.ForeignColumnName
+        End Function
+
+        Public Function GenerateInsertTrigger(ByVal fks As ForeignKeySchema) As TriggerSchema
+            Dim trigger As TriggerSchema = New TriggerSchema()
+            trigger.Name = MakeTriggerName(fks, "fki")
+            trigger.Type = TriggerType.Before
+            trigger.Event = TriggerEvent.Insert
+            trigger.Table = fks.TableName
+            Dim nullString As String = ""
+
+            If fks.IsNullable Then
+                nullString = " NEW." & fks.ColumnName & " IS NOT NULL AND"
+            End If
+
+            trigger.Body = "SELECT RAISE(ROLLBACK, 'insert on table " & fks.TableName & " violates foreign key constraint " & trigger.Name & "')" & " WHERE" & nullString & " (SELECT " & fks.ForeignColumnName & " FROM " & fks.ForeignTableName & " WHERE " & fks.ForeignColumnName & " = NEW." & fks.ColumnName & ") IS NULL; "
+            Return trigger
+        End Function
+
+        Public Function GenerateUpdateTrigger(ByVal fks As ForeignKeySchema) As TriggerSchema
+            Dim trigger As TriggerSchema = New TriggerSchema()
+            trigger.Name = MakeTriggerName(fks, "fku")
+            trigger.Type = TriggerType.Before
+            trigger.Event = TriggerEvent.Update
+            trigger.Table = fks.TableName
+            Dim triggerName As String = trigger.Name
+            Dim nullString As String = ""
+
+            If fks.IsNullable Then
+                nullString = " NEW." & fks.ColumnName & " IS NOT NULL AND"
+            End If
+
+            trigger.Body = "SELECT RAISE(ROLLBACK, 'update on table " & fks.TableName & " violates foreign key constraint " & triggerName & "')" & " WHERE" & nullString & " (SELECT " & fks.ForeignColumnName & " FROM " & fks.ForeignTableName & " WHERE " & fks.ForeignColumnName & " = NEW." & fks.ColumnName & ") IS NULL; "
+            Return trigger
+        End Function
+
+        Public Function GenerateDeleteTrigger(ByVal fks As ForeignKeySchema) As TriggerSchema
+            Dim trigger As TriggerSchema = New TriggerSchema()
+            trigger.Name = MakeTriggerName(fks, "fkd")
+            trigger.Type = TriggerType.Before
+            trigger.Event = TriggerEvent.Delete
+            trigger.Table = fks.ForeignTableName
+            Dim triggerName as String = trigger.Name
+
+            If Not fks.CascadeOnDelete Then
+                trigger.Body = "SELECT RAISE(ROLLBACK, 'delete on table " & fks.ForeignTableName & " violates foreign key constraint " & triggerName & "')" & " WHERE (SELECT " & fks.ColumnName & " FROM " & fks.TableName & " WHERE " & fks.ColumnName & " = OLD." & fks.ForeignColumnName & ") IS NOT NULL; "
+            Else
+                trigger.Body = "DELETE FROM [" & fks.TableName & "] WHERE " & fks.ColumnName & " = OLD." & fks.ForeignColumnName & "; "
+            End If
+
+            Return trigger
+        End Function
+    End Module
+End NameSpace