wip

Author: stephencelis

Sources/StructuredQueries/Macros.swift

@@ -10,7 +10,6 @@ import StructuredQueriesCore
   PartialSelectStatement,
   PrimaryKeyedTable,
   names: named(From),
-  // named(all),
   named(columns),
   named(init(_:)),
   named(init(decoder:)),

Sources/StructuredQueriesCore/Statements/CommonTableExpression.swift

@@ -29,20 +29,28 @@ public struct With<QueryValue>: Statement {
   }
 
   public var query: QueryFragment {
+    guard !statement.isEmpty else { return "" }
+    let cteFragments = ctes.compactMap(\.queryFragment.presence)
+    guard !cteFragments.isEmpty else { return "" }
     var query: QueryFragment = "WITH "
     query.append(
-      "\(ctes.map(\.queryFragment).joined(separator: ", "))\(.newlineOrSpace)\(statement)"
+      "\(cteFragments.joined(separator: ", "))\(.newlineOrSpace)\(statement)"
     )
     return query
   }
 }
 
+extension QueryFragment {
+  fileprivate var presence: Self? { isEmpty ? nil : self }
+}
+
 public struct CommonTableExpressionClause: QueryExpression {
   public typealias QueryValue = ()
   let tableName: QueryFragment
   let select: QueryFragment
   public var queryFragment: QueryFragment {
-    "\(tableName) AS (\(.newline)\(select.indented())\(.newline))"
+    guard !select.isEmpty else { return "" }
+    return "\(tableName) AS (\(.newline)\(select.indented())\(.newline))"
   }
 }
 

Sources/StructuredQueriesCore/Statements/Delete.swift

@@ -8,7 +8,7 @@ extension Table {
   ///
   /// - Returns: A delete statement.
   public static func delete() -> DeleteOf<Self> {
-    Delete()
+    Delete(isEmpty: false)
   }
 }
 
@@ -23,7 +23,7 @@ extension PrimaryKeyedTable {
   /// - Parameter row: A row to delete.
   /// - Returns: A delete statement.
   public static func delete(_ row: Self) -> DeleteOf<Self> {
-    Delete()
+    delete()
       .where {
         $0.primaryKey.eq(TableColumns.PrimaryKey(queryOutput: row[keyPath: $0.primaryKey.keyPath]))
       }
@@ -36,9 +36,9 @@ extension PrimaryKeyedTable {
 ///
 /// To learn more, see <doc:DeleteStatements>.
 public struct Delete<From: Table, Returning> {
+  var isEmpty: Bool
   var `where`: [QueryFragment] = []
   var returning: [QueryFragment] = []
-  var isEmpty = false
 
   /// Adds a condition to a delete statement.
   ///
@@ -108,6 +108,7 @@ public struct Delete<From: Table, Returning> {
       returning.append("\(quote: resultColumn.name)")
     }
     return Delete<From, (repeat each QueryValue)>(
+      isEmpty: isEmpty,
       where: `where`,
       returning: Array(repeat each selection(From.columns))
     )
@@ -127,6 +128,7 @@ public struct Delete<From: Table, Returning> {
       returning.append("\(quote: resultColumn.name)")
     }
     return Delete<From, From>(
+      isEmpty: isEmpty,
       where: `where`,
       returning: returning
     )

Sources/StructuredQueriesCore/Statements/Update.swift

@@ -37,7 +37,7 @@ extension Table {
     or conflictResolution: ConflictResolution? = nil,
     set updates: (inout Updates<Self>) -> Void
   ) -> UpdateOf<Self> {
-    Update(conflictResolution: conflictResolution, updates: Updates(updates))
+    Update(isEmpty: false, conflictResolution: conflictResolution, updates: Updates(updates))
   }
 }
 
@@ -91,11 +91,11 @@ extension PrimaryKeyedTable {
 ///
 /// To learn more, see <doc:UpdateStatements>.
 public struct Update<From: Table, Returning> {
+  var isEmpty: Bool
   var conflictResolution: ConflictResolution?
   var updates: Updates<From>
   var `where`: [QueryFragment] = []
   var returning: [QueryFragment] = []
-  var isEmpty = false
 
   /// Adds a condition to an update statement.
   ///
@@ -160,6 +160,7 @@ public struct Update<From: Table, Returning> {
       returning.append("\(quote: resultColumn.name)")
     }
     return Update<From, (repeat each QueryValue)>(
+      isEmpty: false,
       conflictResolution: conflictResolution,
       updates: updates,
       where: `where`,
@@ -181,6 +182,7 @@ public struct Update<From: Table, Returning> {
       returning.append("\(quote: resultColumn.name)")
     }
     return Update<From, From>(
+      isEmpty: isEmpty,
       conflictResolution: conflictResolution,
       updates: updates,
       where: `where`,

Sources/StructuredQueriesCore/Statements/Where.swift

@@ -479,8 +479,8 @@ extension Where: SelectStatement {
   /// A delete statement for the filtered table.
   public func delete() -> DeleteOf<From> {
     Delete(
-      where: scope == .unscoped ? predicates : From.all._selectClauses.where + predicates,
-      isEmpty: scope == .empty
+      isEmpty: scope == .empty,
+      where: scope == .unscoped ? predicates : From.all._selectClauses.where + predicates
     )
   }
 
@@ -495,10 +495,10 @@ extension Where: SelectStatement {
     set updates: (inout Updates<From>) -> Void
   ) -> UpdateOf<From> {
     Update(
+      isEmpty: scope == .empty,
       conflictResolution: conflictResolution,
       updates: Updates(updates),
-      where: scope == .unscoped ? predicates : From.all._selectClauses.where + predicates,
-      isEmpty: scope == .empty
+      where: scope == .unscoped ? predicates : From.all._selectClauses.where + predicates
     )
   }
 

Sources/StructuredQueriesMacros/TableMacro.swift

@@ -585,9 +585,6 @@ extension TableMacro: ExtensionMacro {
         """
         public typealias From = Swift.Never
         """,
-        // """
-        // public static var all: Where<Self> { none }
-        // """,
       ])
     } else {
       initDecoder = """

Tests/StructuredQueriesTests/CommonTableExpressionTests.swift

@@ -213,6 +213,73 @@ extension SnapshotTests {
       }
     }
 
+    @Test func empty() {
+      assertQuery(
+        With {
+          Reminder
+            .where { !$0.isCompleted }
+            .select { IncompleteReminder.Columns(isFlagged: $0.isFlagged, title: $0.title) }
+        } query: {
+          Reminder
+            .none
+            .delete()
+            .returning(\.title)
+        }
+      ) {
+        """
+
+        """
+      } results: {
+        """
+
+        """
+      }
+      assertQuery(
+        With {
+          Reminder
+            .none
+            .where { !$0.isCompleted }
+            .select { IncompleteReminder.Columns(isFlagged: $0.isFlagged, title: $0.title) }
+        } query: {
+          Reminder
+            .delete()
+            .returning(\.title)
+        }
+      ) {
+        """
+
+        """
+      } results: {
+        """
+
+        """
+      }
+      assertQuery(
+        With {
+          Reminder
+            .none
+            .where { !$0.isCompleted }
+            .select { IncompleteReminder.Columns(isFlagged: $0.isFlagged, title: $0.title) }
+          Reminder
+            .where { !$0.isCompleted }
+            .select { IncompleteReminder.Columns(isFlagged: $0.isFlagged, title: $0.title) }
+        } query: {
+          Reminder
+            .none
+            .delete()
+            .returning(\.title)
+        }
+      ) {
+        """
+
+        """
+      } results: {
+        """
+
+        """
+      }
+    }
+
     @Test func recursive() {
       assertQuery(
         With {