Add playground examples

Author: jberkel

SQLite.playground/Contents.swift

@@ -99,5 +99,33 @@ db.createAggregation("customConcat",
                      initialValue: "users:",
                      reduce: reduce,
                      result: { $0 })
-let result = db.prepare("SELECT customConcat(email) FROM users").scalar() as! String
+let result = try db.prepare("SELECT customConcat(email) FROM users").scalar() as! String
 print(result)
+
+/// schema queries
+let schema = db.schema
+let objects = try schema.objectDefinitions()
+print(objects)
+
+let columns = try schema.columnDefinitions(table: "users")
+print(columns)
+
+/// schema alteration
+
+let schemaChanger = SchemaChanger(connection: db)
+try schemaChanger.alter(table: "users") { table in
+    table.add(.init(name: "age", type: .INTEGER))
+    table.rename(column: "email", to: "electronic_mail")
+    table.drop(column: "name")
+}
+
+let changedColumns = try schema.columnDefinitions(table: "users")
+print(changedColumns)
+
+let age = Expression<Int?>("age")
+let electronicMail = Expression<String>("electronic_mail")
+
+let newRowid = try db.run(users.insert(
+    electronicMail <- "[email protected]",
+    age <- 33
+))

Sources/SQLite/Schema/SchemaDefinitions.swift

@@ -122,7 +122,7 @@ public struct ColumnDefinition: Equatable {
     public init(name: String,
                 primaryKey: PrimaryKey? = nil,
                 type: Affinity,
-                nullable: Bool = false,
+                nullable: Bool = true,
                 defaultValue: LiteralValue = .NULL,
                 references: ForeignKey? = nil) {
         self.name = name

Tests/SQLiteTests/Schema/SchemaDefinitionsTests.swift

@@ -49,6 +49,16 @@ class ColumnDefinitionTests: XCTestCase {
         XCTAssertEqual(definition.toSQL(), expected)
     }
     #endif
+
+    func testNullableByDefault() {
+        let test = ColumnDefinition(name: "test", type: .REAL)
+        XCTAssertEqual(test.name, "test")
+        XCTAssertTrue(test.nullable)
+        XCTAssertEqual(test.defaultValue, .NULL)
+        XCTAssertEqual(test.type, .REAL)
+        XCTAssertNil(test.references)
+        XCTAssertNil(test.primaryKey)
+    }
 }
 
 class AffinityTests: XCTestCase {