Make ForeignKey public, rename fields for clarity

Author: jberkel

Sources/SQLite/Schema/SchemaDefinitions.swift

@@ -117,11 +117,24 @@ public struct ColumnDefinition: Equatable {
     }
 
     public struct ForeignKey: Equatable {
-        let table: String
-        let column: String
-        let primaryKey: String?
+        let fromColumn: String
+        let toTable: String
+        // when null, use primary key of "toTable"
+        let toColumn: String?
         let onUpdate: String?
         let onDelete: String?
+
+        public init(toTable: String, toColumn: String? = nil, onUpdate: String? = nil, onDelete: String? = nil) {
+            self.init(fromColumn: "", toTable: toTable, toColumn: toColumn, onUpdate: onUpdate, onDelete: onDelete)
+        }
+
+        public init(fromColumn: String, toTable: String, toColumn: String? = nil, onUpdate: String? = nil, onDelete: String? = nil) {
+            self.fromColumn = fromColumn
+            self.toTable = toTable
+            self.toColumn = toColumn
+            self.onUpdate = onUpdate
+            self.onDelete = onDelete
+        }
     }
 
     public let name: String
@@ -400,8 +413,8 @@ extension ColumnDefinition.ForeignKey {
     func toSQL() -> String {
         ([
             "REFERENCES",
-            table.quote(),
-            primaryKey.map { "(\($0.quote()))" },
+            toTable.quote(),
+            toColumn.map { "(\($0.quote()))" },
             onUpdate.map { "ON UPDATE \($0)" },
             onDelete.map { "ON DELETE \($0)" }
         ] as [String?]).compactMap { $0 }

Sources/SQLite/Schema/SchemaReader.swift

@@ -19,7 +19,7 @@ public class SchemaReader {
         }
 
         let foreignKeys: [String: [ColumnDefinition.ForeignKey]] =
-            Dictionary(grouping: try foreignKeys(table: table), by: { $0.column })
+            Dictionary(grouping: try foreignKeys(table: table), by: { $0.fromColumn })
 
         let columnDefinitions = try connection.prepareRowIterator("PRAGMA table_info(\(table.quote()))")
             .map { (row: Row) -> ColumnDefinition in
@@ -111,9 +111,9 @@ public class SchemaReader {
         try connection.prepareRowIterator("PRAGMA foreign_key_list(\(table.quote()))")
             .map { row in
                 ColumnDefinition.ForeignKey(
-                    table: row[ForeignKeyListTable.tableColumn],
-                    column: row[ForeignKeyListTable.fromColumn],
-                    primaryKey: row[ForeignKeyListTable.toColumn],
+                    fromColumn: row[ForeignKeyListTable.fromColumn],
+                    toTable: row[ForeignKeyListTable.tableColumn],
+                    toColumn: row[ForeignKeyListTable.toColumn],
                     onUpdate: row[ForeignKeyListTable.onUpdateColumn] == TableBuilder.Dependency.noAction.rawValue
                         ? nil : row[ForeignKeyListTable.onUpdateColumn],
                     onDelete: row[ForeignKeyListTable.onDeleteColumn] == TableBuilder.Dependency.noAction.rawValue

Tests/SQLiteTests/Schema/SchemaChangerTests.swift

@@ -269,4 +269,38 @@ class SchemaChangerTests: SQLiteTestCase {
             table.add(index: .init(table: "foo", name: "name_index", unique: true, columns: ["name"], indexSQL: nil))
         }
     }
+
+    func test_create_table_with_foreign_key_reference() throws {
+        try schemaChanger.create(table: "foo") { table in
+            table.add(column: .init(name: "id", primaryKey: .init(autoIncrement: true), type: .INTEGER))
+        }
+
+        try schemaChanger.create(table: "bars") { table in
+            table.add(column: .init(name: "id", primaryKey: .init(autoIncrement: true), type: .INTEGER))
+            table.add(column: .init(name: "foo_id",
+                                    type: .INTEGER,
+                                    nullable: false,
+                                    references: .init(toTable: "foo", toColumn: "id")))
+        }
+
+        let barColumns = try schema.columnDefinitions(table: "bars")
+
+        XCTAssertEqual([
+            ColumnDefinition(name: "id",
+                             primaryKey: .init(autoIncrement: true, onConflict: nil),
+                             type: .INTEGER,
+                             nullable: true,
+                             unique: false,
+                             defaultValue: .NULL,
+                             references: nil),
+
+            ColumnDefinition(name: "foo_id",
+                             primaryKey: nil,
+                             type: .INTEGER,
+                             nullable: false,
+                             unique: false,
+                             defaultValue: .NULL,
+                             references: .init(fromColumn: "foo_id", toTable: "foo", toColumn: "id", onUpdate: nil, onDelete: nil))
+        ], barColumns)
+    }
 }

Tests/SQLiteTests/Schema/SchemaDefinitionsTests.swift

@@ -11,7 +11,7 @@ class ColumnDefinitionTests: XCTestCase {
 
         ("\"other_id\" INTEGER NOT NULL REFERENCES \"other_table\" (\"some_id\")",
         ColumnDefinition(name: "other_id", primaryKey: nil, type: .INTEGER, nullable: false, defaultValue: .NULL,
-                         references: .init(table: "other_table", column: "", primaryKey: "some_id", onUpdate: nil, onDelete: nil))),
+                         references: .init(fromColumn: "", toTable: "other_table", toColumn: "some_id", onUpdate: nil, onDelete: nil))),
 
         ("\"text\" TEXT",
         ColumnDefinition(name: "text", primaryKey: nil, type: .TEXT, nullable: true, defaultValue: .NULL, references: nil)),
@@ -245,9 +245,9 @@ class ForeignKeyDefinitionTests: XCTestCase {
     func test_toSQL() {
         XCTAssertEqual(
             ColumnDefinition.ForeignKey(
-                table: "foo",
-                column: "bar",
-                primaryKey: "bar_id",
+                fromColumn: "bar",
+                toTable: "foo",
+                toColumn: "bar_id",
                 onUpdate: nil,
                 onDelete: "SET NULL"
             ).toSQL(), """

Tests/SQLiteTests/Schema/SchemaReaderTests.swift

@@ -54,7 +54,7 @@ class SchemaReaderTests: SQLiteTestCase {
                              nullable: true,
                              unique: false,
                              defaultValue: .NULL,
-                             references: .init(table: "users", column: "manager_id", primaryKey: "id", onUpdate: nil, onDelete: nil)),
+                             references: .init(fromColumn: "manager_id", toTable: "users", toColumn: "id", onUpdate: nil, onDelete: nil)),
             ColumnDefinition(name: "created_at",
                              primaryKey: nil,
                              type: .NUMERIC,
@@ -194,7 +194,7 @@ class SchemaReaderTests: SQLiteTestCase {
 
         let foreignKeys = try schemaReader.foreignKeys(table: "test_links")
         XCTAssertEqual(foreignKeys, [
-            .init(table: "users", column: "test_id", primaryKey: "id", onUpdate: nil, onDelete: nil)
+            .init(fromColumn: "test_id", toTable: "users", toColumn: "id", onUpdate: nil, onDelete: nil)
         ])
     }