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+# Search Criteria SQL Extraction Functions - Design
+
+## Purpose
+
+Create SQL Server functions to extract values from the `Search.Criteria` JSON column, eliminating the need for C# to deserialize criteria and pass Table-Valued Parameters to SQL Server. The query builder will generate SQL that extracts filter values directly from the database.
+
+## Goals
+
+1. Create 11 SQL functions to extract scalar and table values from SearchCriteria JSON
+2. Remove Table Type dependencies (7 TVP types)
+3. Simplify C# query generation to pass only SearchId
+4. Add comprehensive Database.Tests for the new functions
+5. Update documentation and specifications
+
+## Architecture
+
+### SQL Server Version
+- **Target:** SQL Server 2022
+- **JSON Functions:** `OPENJSON()`, `JSON_VALUE()`, `ISJSON()`
+
+### Function Types
+
+**Scalar Functions (3):**
+| Function | Returns | JSON Path |
+|----------|---------|-----------|
+| `dbo.fn_GetSearchMinimumDt` | `DATETIME2(7)` | `$.MinimumDt` |
+| `dbo.fn_GetSearchMaximumDt` | `DATETIME2(7)` | `$.MaximumDt` |
+| `dbo.fn_GetSearchExtractMisData` | `BIT` | `$.ExtractMisData` |
+
+**Simple Table Functions (5):**
+| Function | Returns | JSON Path |
+|----------|---------|-----------|
+| `dbo.fn_GetSearchWorkOrders` | `TABLE(WorkOrderNumber BIGINT)` | `$.WorkOrderNumbers` |
+| `dbo.fn_GetSearchItemNumbers` | `TABLE(ItemNumber VARCHAR(128))` | `$.ItemNumbers` |
+| `dbo.fn_GetSearchProfitCenters` | `TABLE(Code VARCHAR(12))` | `$.ProfitCenters` |
+| `dbo.fn_GetSearchWorkCenters` | `TABLE(Code VARCHAR(12))` | `$.WorkCenters` |
+| `dbo.fn_GetSearchOperatorIDs` | `TABLE(OperatorID VARCHAR(128))` | `$.OperatorIDs` |
+
+**Complex Table Functions (2):**
+| Function | Returns | JSON Path |
+|----------|---------|-----------|
+| `dbo.fn_GetSearchComponentLots` | `TABLE(LotNumber VARCHAR(30), ItemNumber VARCHAR(128))` | `$.ComponentLotNumbers[*]` |
+| `dbo.fn_GetSearchPartOperations` | `TABLE(ItemNumber VARCHAR(128), OperationNumber VARCHAR(10), MisNumber VARCHAR(10), MisRevision VARCHAR(10))` | `$.PartOperations[*]` |
+
+### Error Handling
+
+All functions validate inputs and throw errors for invalid conditions:
+
+| Error Code | Condition | Message Pattern |
+|------------|-----------|-----------------|
+| 50001 | SearchId not found | `Search ID {id} not found` |
+| 50002 | Criteria is NULL or empty | `Search ID {id} has no criteria` |
+| 50003 | Criteria is invalid JSON | `Search ID {id} has invalid JSON` |
+
+**Normal empty results (no error):**
+- JSON valid but property missing
+- JSON valid, property is `[]` or `null`
+
+### Multi-Statement TVF Pattern
+
+Table functions use multi-statement TVFs for proper error handling:
+
+```sql
+CREATE FUNCTION dbo.fn_GetSearchWorkOrders(@SearchId INT)
+RETURNS @Results TABLE (WorkOrderNumber BIGINT NOT NULL)
+AS
+BEGIN
+    DECLARE @Criteria VARCHAR(MAX);
+    DECLARE @ErrorMsg NVARCHAR(400);
+
+    -- Get criteria
+    SELECT @Criteria = Criteria
+    FROM dbo.Search
+    WHERE ID = @SearchId;
+
+    -- Validate search exists
+    IF @@ROWCOUNT = 0
+    BEGIN
+        SET @ErrorMsg = CONCAT('Search ID ', @SearchId, ' not found');
+        THROW 50001, @ErrorMsg, 1;
+    END
+
+    -- Validate criteria not null/empty
+    IF @Criteria IS NULL OR @Criteria = ''
+    BEGIN
+        SET @ErrorMsg = CONCAT('Search ID ', @SearchId, ' has no criteria');
+        THROW 50002, @ErrorMsg, 1;
+    END
+
+    -- Validate JSON
+    IF ISJSON(@Criteria) = 0
+    BEGIN
+        SET @ErrorMsg = CONCAT('Search ID ', @SearchId, ' has invalid JSON');
+        THROW 50003, @ErrorMsg, 1;
+    END
+
+    -- Extract values (returns empty if property missing/null/empty array)
+    INSERT INTO @Results (WorkOrderNumber)
+    SELECT CAST(value AS BIGINT)
+    FROM OPENJSON(@Criteria, '$.WorkOrderNumbers');
+
+    RETURN;
+END
+```
+
+## Migration Scripts
+
+### New Scripts
+
+**045_CreateScalarExtractionFunctions.sql**
+- `fn_GetSearchMinimumDt`
+- `fn_GetSearchMaximumDt`
+- `fn_GetSearchExtractMisData`
+
+**046_CreateSimpleTableFunctions.sql**
+- `fn_GetSearchWorkOrders`
+- `fn_GetSearchItemNumbers`
+- `fn_GetSearchProfitCenters`
+- `fn_GetSearchWorkCenters`
+- `fn_GetSearchOperatorIDs`
+
+**047_CreateComplexTableFunctions.sql**
+- `fn_GetSearchComponentLots`
+- `fn_GetSearchPartOperations`
+
+### Scripts to Delete
+
+Remove obsolete Table Type scripts:
+- `033_CreateWorkOrderFilterParameterType.sql`
+- `034_CreateItemNumberFilterParameterType.sql`
+- `035_CreateProfitCenterFilterParameterType.sql`
+- `036_CreateWorkCenterFilterParameterType.sql`
+- `037_CreateOperatorFilterParameterType.sql`
+- `038_CreateComponentLotFilterParameterType.sql`
+- `039_CreateItemOperationMisFilterParameterType.sql`
+
+## C# Changes
+
+### Files to Delete
+
+```
+src/JdeScoping.DataAccess/
+├── Extensions/
+│   └── TableValuedParameterExtensions.cs
+├── Models/FilterEntries/
+│   ├── WorkOrderFilterEntry.cs
+│   ├── ItemNumberFilterEntry.cs
+│   ├── ProfitCenterFilterEntry.cs
+│   ├── WorkCenterFilterEntry.cs
+│   ├── OperatorFilterEntry.cs
+│   ├── ComponentLotFilterEntry.cs
+│   └── ItemOperationMisFilterEntry.cs
+```
+
+### Files to Modify
+
+**`ISearchQueryBuilder.cs`** - New signature:
+```csharp
+SearchQueryResult BuildSearchQuery(int searchId);
+SearchQueryResult BuildMisQuery(int searchId);
+SearchQueryResult BuildMisNonMatchQuery(int searchId);
+```
+
+**`SqlKataSearchQueryBuilder.cs`** - Generate SQL using functions:
+```sql
+-- Instead of TVP temp table population:
+INSERT INTO #P_WorkOrders SELECT * FROM dbo.fn_GetSearchWorkOrders(@SearchId)
+```
+
+**`SearchModel.cs`** - Simplify:
+- Remove all `List<*FilterEntry>` properties
+- Remove all `*FilterEnabled` computed properties
+- Keep: `Id`, `UserName`, `Name`, timestamps, results
+
+**`SearchProcessor.cs`** - Pass `searchId` instead of filter lists
+
+## Test Structure
+
+```
+tests/JdeScoping.Database.Tests/
+├── Infrastructure/
+│   └── DatabaseTestBase.cs
+├── Functions/
+│   ├── ScalarFunctionTests.cs
+│   ├── SimpleTableFunctionTests.cs
+│   └── ComplexTableFunctionTests.cs
+```
+
+### Test Categories
+
+**Happy Path:** Valid JSON, correct extraction, empty arrays
+**Error Tests:** Non-existent SearchId, NULL criteria, invalid JSON
+**Edge Cases:** Large arrays, special characters, NULL values in arrays, Unicode
+
+### Test Infrastructure
+
+Share with `Api.IntegrationTests` via `TestWebApplicationFactory` pattern.
+
+## Documentation Updates
+
+### OpenSpec Specifications
+- Update `openspec/specs/data-access/spec.md` - Remove TVP references, add function requirements
+- Update `openspec/specs/search-processing/spec.md` - Update query generation
+- Update `openspec/specs/database-schema/spec.md` - Document extraction functions
+
+### DOCUMENTATION Folder
+- Update architecture diagrams
+- Add `DOCUMENTATION/Database/ExtractionFunctions.md`
+- Update testing documentation
+
+## Implementation Order
+
+### Phase 1: SQL Functions
+1. Create `045_CreateScalarExtractionFunctions.sql`
+2. Create `046_CreateSimpleTableFunctions.sql`
+3. Create `047_CreateComplexTableFunctions.sql`
+4. Delete obsolete Table Type scripts (033-039)
+5. Renumber remaining scripts (040-044 → 033-037)
+
+### Phase 2: Database Tests
+6. Set up `DatabaseTestBase.cs`
+7. Write `ScalarFunctionTests.cs`
+8. Write `SimpleTableFunctionTests.cs`
+9. Write `ComplexTableFunctionTests.cs`
+10. Verify all tests pass
+
+### Phase 3: C# Refactor
+11. Update `ISearchQueryBuilder` interface
+12. Update `SqlKataSearchQueryBuilder`
+13. Update `SearchProcessor`
+14. Simplify `SearchModel`
+15. Delete `TableValuedParameterExtensions.cs`
+16. Delete `FilterEntries/*.cs`
+17. Update/delete related tests
+
+### Phase 4: Integration & Verification
+18. Run full test suite
+19. Fix broken tests
+20. Manual end-to-end verification
+
+### Phase 5: Documentation
+21. Update OpenSpec specifications
+22. Update architecture documentation
+23. Add Database.Tests documentation
+24. Create ExtractionFunctions.md reference
+
+## Acceptance Criteria
+
+- [ ] All 11 SQL functions created and working
+- [ ] Error codes 50001/50002/50003 thrown for invalid inputs
+- [ ] Empty results returned for missing/null/empty properties
+- [ ] Table Type scripts removed
+- [ ] C# TVP code removed
+- [ ] Query builder uses SearchId parameter only
+- [ ] Database.Tests passing (all categories)
+- [ ] Existing integration tests passing
+- [ ] Documentation updated