# 20260513185108_MakeKnowledgeUnitEbookIdNullable

- File ID: file:u0dg0d:20260513185108-makeknowledgeunitebookidnullable-
- Path: NexusReader.Data/Persistence/Migrations/20260513185108_MakeKnowledgeUnitEbookIdNullable.cs
- Role: database-config
- Layer: data

## Purpose

EF Core migration that makes the KnowledgeUnits.EbookId column nullable in the database schema and provides a reversible Down migration.

## Key Details

Up makes KnowledgeUnits.EbookId nullable (uuid); Down makes it non-nullable and assigns an all-zero Guid default.

## Symbols

- MakeKnowledgeUnitEbookIdNullable: EF Core migration that makes the KnowledgeUnits.EbookId column nullable in the database schema and provides a reversible Down migration.
- Up(): Applies the schema change to alter KnowledgeUnits.EbookId to be nullable.
- Down(): Reverts the schema change by making KnowledgeUnits.EbookId non-nullable and setting a default Guid value.
- MakeKnowledgeUnitEbookIdNullable: Represents an EF Core migration that changes the EbookId nullability on KnowledgeUnits.

## Dependencies

- No resolved dependencies.

## Calls

- No resolved calls.

## Coverage

- Symbols: 4
- Executable symbols: 2
- Executable symbols with control flow: 2
- Grounded edges: 4
- Unresolved references: 0
- Control-flow fragments: 2
- Unresolved jumps: 0
- Unsupported constructs: 0
- Control-flow coverage: 100%
- Required diagrams: 2
- Generated diagrams: 2

## Control Flow Fragments

- Up: 3 nodes, 2 edges, 0 jumps, 0 unsupported constructs
- Down: 3 nodes, 2 edges, 0 jumps, 0 unsupported constructs

## Diagrams

### 20260513185108_MakeKnowledgeUnitEbookIdNullable Neighborhood

```mermaid
flowchart LR
    class_1gb1hzf_makeknowledgeunitebookidnullable("MakeKnowledgeUnitEbookIdNullable")
    file_u0dg0d_20260513185108_makeknowledgeunitebookidnullable_("20260513185108_MakeKnowledgeUnitEbookIdNullable")
    method_1xywi1n_down[["Down()"]]
    method_jenau5_up[["Up()"]]
    type_1e3plwu_makeknowledgeunitebookidnullable[/"MakeKnowledgeUnitEbookIdNullable"/]
```

### 20260513185108_MakeKnowledgeUnitEbookIdNullable Execution Overview

```mermaid
flowchart TD
    class_1gb1hzf_makeknowledgeunitebookidnullable("MakeKnowledgeUnitEbookIdNullable")
    method_1xywi1n_down[["Down()"]]
    method_jenau5_up[["Up()"]]
    class_1gb1hzf_makeknowledgeunitebookidnullable -->|contains| method_1xywi1n_down
    class_1gb1hzf_makeknowledgeunitebookidnullable -->|contains| method_jenau5_up
```

## Diagram Validation

- Status: pass
