Properly expand table.* columns

Signed-off-by: Stephen Celis <stephen@stephencelis.com>

SQLite Common Tests/QueryTests.swift

@@ -101,6 +101,22 @@ class QueryTests: XCTestCase {
         ExpectExecutions(db, [SQL: 1]) { _ in for _ in middleManagers {} }
     }
 
+    func test_join_withNamespacedStar_expandsColumnNames() {
+        let managers = db["users"].alias("managers")
+
+        let aliceID = users.insert(email <- "alice@example.com")!
+        users.insert(email <- "betty@example.com", manager_id <- aliceID)!
+
+        let query = users
+            .select(users[*], managers[*])
+            .join(managers, on: managers[id] == users[manager_id])
+
+        let SQL = "SELECT \"users\".*, \"managers\".* FROM \"users\" " +
+            "INNER JOIN \"users\" AS \"managers\" " +
+            "ON (\"managers\".\"id\" = \"users\".\"manager_id\")"
+        ExpectExecutions(db, [SQL: 1]) { _ in for row in query { println(row) } }
+    }
+
     func test_namespacedColumnRowValueAccess() {
         let aliceID = users.insert(email <- "alice@example.com")!
         let bettyID = users.insert(email <- "betty@example.com", manager_id <- aliceID)!

SQLite Common/Query.swift

@@ -753,7 +753,7 @@ public struct QueryGenerator: GeneratorType {
 
     private lazy var columnNames: [String: Int] = {
         var (columnNames, idx) = ([String: Int](), 0)
-        for each in self.query.columns {
+        column: for each in self.query.columns {
             let pair = split(each.expression.SQL) { $0 == "." }
             let (tableName, column) = (pair.count > 1 ? pair.first : nil, pair.last!)
 
@@ -766,11 +766,16 @@ public struct QueryGenerator: GeneratorType {
             }
 
             if column == "*" {
+                let tables = [self.query] + self.query.joins.map { $0.table }
                 if let tableName = tableName {
-                    expandGlob(true)(self.query.database[tableName])
-                    continue
+                    for table in tables {
+                        if quote(identifier: table.alias ?? table.tableName) == tableName {
+                            expandGlob(true)(table)
+                            continue column
+                        }
+                    }
+                    assertionFailure("no such table: \(tableName)")
                 }
-                let tables = [self.query] + self.query.joins.map { $0.table }
                 tables.map(expandGlob(self.query.joins.count > 0))
                 continue
             }