Batch updates

CHANGELOG.md

@@ -6,9 +6,7 @@ All notable changes to this project will be documented in this file.
 GRDB adheres to [Semantic Versioning](https://semver.org/), with one expection: APIs flagged [**:fire: EXPERIMENTAL**](README.md#what-are-experimental-features). Those are unstable, and may break between any two minor releases of the library.
 
 
-<!--
 [Next Release](#next-release)
--->
 
 
 #### 4.x Releases
@@ -58,9 +56,16 @@ GRDB adheres to [Semantic Versioning](https://semver.org/), with one expection:
 - [0.110.0](#01100), ...
 
 
-<!--
 ## Next Release
--->
+
+**New**
+
+- [#646](https://github.com/groue/GRDB.swift/pull/646): Batch updates
+
+### Documentation Diff
+
+The [Update Requests](README.md#update-requests) chapter documents the new support for batch updates introduced in the [query interface](README.md#the-query-interface).
+
 
 ## 4.5.0
 

GRDB.xcodeproj/project.pbxproj

@@ -110,6 +110,9 @@
 		56176C7D1EACCD2D000F3F2B /* EncryptionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 567156701CB18050007DC145 /* EncryptionTests.swift */; };
 		56176C7F1EACCD2F000F3F2B /* EncryptionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 567156701CB18050007DC145 /* EncryptionTests.swift */; };
 		56193E8E1CD8A3E200F95862 /* FetchedRecordsController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 31A7787C1C6A4DD600F507F6 /* FetchedRecordsController.swift */; };
+		561CFA7823735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 561CFA7123735015000C8BAA /* MutablePersistableRecordUpdateTests.swift */; };
+		561CFA7923735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 561CFA7123735015000C8BAA /* MutablePersistableRecordUpdateTests.swift */; };
+		561CFA7A23735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 561CFA7123735015000C8BAA /* MutablePersistableRecordUpdateTests.swift */; };
 		562205F11E420E47005860AC /* DatabasePoolReleaseMemoryTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 563363CF1C943D13000BE133 /* DatabasePoolReleaseMemoryTests.swift */; };
 		562205F21E420E47005860AC /* DatabasePoolSchemaCacheTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 569531281C908A5B00CF1A2B /* DatabasePoolSchemaCacheTests.swift */; };
 		562205F31E420E47005860AC /* DatabaseQueueReleaseMemoryTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 563363D41C94484E000BE133 /* DatabaseQueueReleaseMemoryTests.swift */; };
@@ -1333,6 +1336,7 @@
 		561667001D08A49900ADD404 /* FoundationNSDecimalNumberTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FoundationNSDecimalNumberTests.swift; sourceTree = "<group>"; };
 		5616AAF0207CD45E00AC3664 /* RequestProtocols.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RequestProtocols.swift; sourceTree = "<group>"; };
 		56172947223533F40006E219 /* EncodableRecord.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = EncodableRecord.swift; sourceTree = "<group>"; };
+		561CFA7123735015000C8BAA /* MutablePersistableRecordUpdateTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MutablePersistableRecordUpdateTests.swift; sourceTree = "<group>"; };
 		562393171DECC02000A6B01F /* RowFetchTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RowFetchTests.swift; sourceTree = "<group>"; };
 		5623932F1DEDFC5700A6B01F /* AnyCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AnyCursorTests.swift; sourceTree = "<group>"; };
 		5623934D1DEDFEFB00A6B01F /* EnumeratedCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = EnumeratedCursorTests.swift; sourceTree = "<group>"; };
@@ -1837,6 +1841,7 @@
 				5674A71C1F30A8DF0095F066 /* MutablePersistableRecordEncodableTests.swift */,
 				56B021C81D8C0D3900B239BB /* MutablePersistableRecordPersistenceConflictPolicyTests.swift */,
 				563363A91C933FF8000BE133 /* MutablePersistableRecordTests.swift */,
+				561CFA7123735015000C8BAA /* MutablePersistableRecordUpdateTests.swift */,
 				563363AA1C933FF8000BE133 /* PersistableRecordTests.swift */,
 			);
 			name = PersistableRecord;
@@ -3527,6 +3532,7 @@
 				56A5EF131EF7F20B00F03071 /* ForeignKeyInfoTests.swift in Sources */,
 				5653EAE920944B4F00F46237 /* AssociationChainSQLTests.swift in Sources */,
 				5698ACD21DA8C2620056AF8C /* RecordPrimaryKeyHiddenRowIDTests.swift in Sources */,
+				561CFA7923735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */,
 				56A238621B9C74A90082EB20 /* RecordEditedTests.swift in Sources */,
 				5653EAE120944B4F00F46237 /* AssociationTableAliasTestsSQLTests.swift in Sources */,
 				5653EAE720944B4F00F46237 /* AssociationBelongsToFetchableRecordTests.swift in Sources */,
@@ -3729,6 +3735,7 @@
 				5698AC401DA2BED90056AF8C /* FTS3PatternTests.swift in Sources */,
 				562393571DEE013C00A6B01F /* FilterCursorTests.swift in Sources */,
 				5653EAE820944B4F00F46237 /* AssociationChainSQLTests.swift in Sources */,
+				561CFA7823735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */,
 				56A5EF0F1EF7F20B00F03071 /* ForeignKeyInfoTests.swift in Sources */,
 				56D496B61D813434008276D7 /* DatabaseRegionTests.swift in Sources */,
 				5653EAE020944B4F00F46237 /* AssociationTableAliasTestsSQLTests.swift in Sources */,
@@ -4064,6 +4071,7 @@
 				AAA4DD8B230F262000C74B15 /* ForeignKeyInfoTests.swift in Sources */,
 				AAA4DD8C230F262000C74B15 /* AssociationChainSQLTests.swift in Sources */,
 				AAA4DD8D230F262000C74B15 /* RecordPrimaryKeyHiddenRowIDTests.swift in Sources */,
+				561CFA7A23735016000C8BAA /* MutablePersistableRecordUpdateTests.swift in Sources */,
 				AAA4DD8E230F262000C74B15 /* RecordEditedTests.swift in Sources */,
 				AAA4DD8F230F262000C74B15 /* AssociationTableAliasTestsSQLTests.swift in Sources */,
 				AAA4DD90230F262000C74B15 /* AssociationBelongsToFetchableRecordTests.swift in Sources */,

GRDB/QueryInterface/Request/QueryInterfaceRequest.swift

@@ -478,7 +478,7 @@ extension QueryInterfaceRequest: DerivableRequest where T: TableRecord { }
 
 extension QueryInterfaceRequest where T: MutablePersistableRecord {
 
-    // MARK: Deleting
+    // MARK: Batch Delete
 
     /// Deletes matching rows; returns the number of deleted rows.
     ///
@@ -490,6 +490,52 @@ extension QueryInterfaceRequest where T: MutablePersistableRecord {
         try SQLQueryGenerator(query).makeDeleteStatement(db).execute()
         return db.changesCount
     }
+
+    // MARK: Batch Update
+
+    /// Updates matching rows; returns the number of updated rows.
+    ///
+    /// For example:
+    ///
+    ///     try dbQueue.write { db in
+    ///         // UPDATE player SET score = 0
+    ///         try Player.all().updateAll(db, [Column("score") <- 0])
+    ///     }
+    ///
+    /// - parameter db: A database connection.
+    /// - returns: The number of updated rows
+    /// - throws: A DatabaseError is thrown whenever an SQLite error occurs.
+    @discardableResult
+    public func updateAll(_ db: Database, _ assignments: [ColumnAssignment]) throws -> Int {
+        guard let updateStatement = try SQLQueryGenerator(query).makeUpdateStatement(db, assignments) else {
+            // database not hit
+            return 0
+        }
+        try updateStatement.execute()
+        return db.changesCount
+    }
+
+    /// Updates matching rows; returns the number of updated rows.
+    ///
+    /// For example:
+    ///
+    ///     try dbQueue.write { db in
+    ///         // UPDATE player SET score = 0
+    ///         try Player.all().updateAll(db, Column("score") <- 0)
+    ///     }
+    ///
+    /// - parameter db: A database connection.
+    /// - returns: The number of updated rows
+    /// - throws: A DatabaseError is thrown whenever an SQLite error occurs.
+    @discardableResult
+    public func updateAll(
+        _ db: Database,
+        _ assignment: ColumnAssignment,
+        _ otherAssignments: ColumnAssignment...)
+        throws -> Int
+    {
+        return try updateAll(db, [assignment] + otherAssignments)
+    }
 }
 
 // MARK: - Eager loading of hasMany associations
@@ -574,3 +620,94 @@ extension Row {
         }
     }
 }
+
+// MARK: - ColumnAssignment
+
+precedencegroup ColumnAssignment {
+    associativity: left
+    assignment: true
+    lowerThan: AssignmentPrecedence
+}
+
+infix operator <- : ColumnAssignment
+
+/// A ColumnAssignment can update rows in the database.
+///
+/// You create an assignment from a column and an assignment operator, such as
+/// `<-` or `+=`:
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = 0
+///         let assignment = Column("score") <- 0
+///         try Player.updateAll(db, assignment)
+///     }
+public struct ColumnAssignment {
+    var column: ColumnExpression
+    var value: SQLExpressible
+}
+
+/// Creates an assignment to a value.
+///
+///     Column("valid") <- true
+///     Column("score") <- 0
+///     Column("score") <- Column("score") + Column("bonus")
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = 0
+///         try Player.updateAll(db, Column("score") <- 0)
+///     }
+public func <- (column: ColumnExpression, value: SQLExpressible) -> ColumnAssignment {
+    return ColumnAssignment(column: column, value: value)
+}
+
+/// Creates an assignment that adds a value
+///
+///     Column("score") += 1
+///     Column("score") += Column("bonus")
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = score + 1
+///         try Player.updateAll(db, Column("score") += 1)
+///     }
+public func += (column: ColumnExpression, value: SQLExpressible) -> ColumnAssignment {
+    return column <- column + value
+}
+
+/// Creates an assignment that subtracts a value
+///
+///     Column("score") -= 1
+///     Column("score") -= Column("bonus")
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = score - 1
+///         try Player.updateAll(db, Column("score") -= 1)
+///     }
+public func -= (column: ColumnExpression, value: SQLExpressible) -> ColumnAssignment {
+    return column <- column - value
+}
+
+/// Creates an assignment that multiplies by a value
+///
+///     Column("score") *= 2
+///     Column("score") *= Column("factor")
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = score * 2
+///         try Player.updateAll(db, Column("score") *= 2)
+///     }
+public func *= (column: ColumnExpression, value: SQLExpressible) -> ColumnAssignment {
+    return column <- column * value
+}
+
+/// Creates an assignment that divides by a value
+///
+///     Column("score") /= 2
+///     Column("score") /= Column("factor")
+///
+///     try dbQueue.write { db in
+///         // UPDATE player SET score = score / 2
+///         try Player.updateAll(db, Column("score") /= 2)
+///     }
+public func /= (column: ColumnExpression, value: SQLExpressible) -> ColumnAssignment {
+    return column <- column / value
+}

GRDB/QueryInterface/SQLGeneration/SQLQueryGenerator.swift

@@ -161,19 +161,71 @@ struct SQLQueryGenerator {
             if !orderings.isEmpty {
                 sql += " ORDER BY " + orderings.map { $0.orderingTermSQL(&context) }.joined(separator: ", ")
             }
-
-            if Database.sqliteCompileOptions.contains("ENABLE_UPDATE_DELETE_LIMIT") {
-                sql += " LIMIT " + limit.sql
-            } else {
-                fatalError("Can't delete query with limit")
-            }
+            sql += " LIMIT " + limit.sql
         }
 
         let statement = try db.makeUpdateStatement(sql: sql)
         statement.arguments = context.arguments!
         return statement
     }
 
+    /// Returns nil if assignments is empty
+    func makeUpdateStatement(_ db: Database, _ assignments: [ColumnAssignment]) throws -> UpdateStatement? {
+        if let groupExpressions = try groupPromise?.resolve(db), !groupExpressions.isEmpty {
+            // Programmer error
+            fatalError("Can't update query with GROUP BY clause")
+        }
+
+        guard havingExpressions.isEmpty else {
+            // Programmer error
+            fatalError("Can't update query with HAVING clause")
+        }
+
+        guard relation.joins.isEmpty else {
+            // Programmer error
+            fatalError("Can't update query with JOIN clause")
+        }
+
+        guard case .table = relation.source else {
+            // Programmer error
+            fatalError("Can't update without any database table")
+        }
+
+        if assignments.isEmpty {
+            return nil
+        }
+
+        var context = SQLGenerationContext.queryGenerationContext(aliases: relation.allAliases)
+
+        var sql = try "UPDATE " + relation.source.sql(db, &context)
+
+        let assignmentsSQL = assignments
+            .map({ assignment in
+                assignment.column.expressionSQL(&context, wrappedInParenthesis: false) +
+                    " = " +
+                    assignment.value.sqlExpression.expressionSQL(&context, wrappedInParenthesis: false)
+            })
+            .joined(separator: ", ")
+        sql += " SET " + assignmentsSQL
+
+        let filters = try relation.filtersPromise.resolve(db)
+        if filters.isEmpty == false {
+            sql += " WHERE " + SQLExpressionAnd(filters).expressionSQL(&context, wrappedInParenthesis: false)
+        }
+
+        if let limit = limit {
+            let orderings = try relation.ordering.resolve(db)
+            if !orderings.isEmpty {
+                sql += " ORDER BY " + orderings.map { $0.orderingTermSQL(&context) }.joined(separator: ", ")
+            }
+            sql += " LIMIT " + limit.sql
+        }
+
+        let statement = try db.makeUpdateStatement(sql: sql)
+        statement.arguments = context.arguments!
+        return statement
+    }
+
     /// Returns a select statement
     func makeSelectStatement(_ db: Database) throws -> SelectStatement {
         // Build an SQK generation context with all aliases found in the query,

GRDB/Record/PersistableRecord.swift

@@ -506,7 +506,7 @@ extension MutablePersistableRecord where Self: AnyObject {
 
 extension MutablePersistableRecord {
 
-    // MARK: - Deleting All
+    // MARK: Batch Delete
 
     /// Deletes all records; returns the number of deleted rows.
     ///
@@ -517,6 +517,47 @@ extension MutablePersistableRecord {
     public static func deleteAll(_ db: Database) throws -> Int {
         return try all().deleteAll(db)
     }
+
+    // MARK: Batch Update
+
+    /// Updates all records; returns the number of updated records.
+    ///
+    /// For example:
+    ///
+    ///     try dbQueue.write { db in
+    ///         // UPDATE player SET score = 0
+    ///         try Player.updateAll(db, [Column("score") <- 0])
+    ///     }
+    ///
+    /// - parameter db: A database connection.
+    /// - returns: The number of updated rows
+    /// - throws: A DatabaseError is thrown whenever an SQLite error occurs.
+    @discardableResult
+    public static func updateAll(_ db: Database, _ assignments: [ColumnAssignment]) throws -> Int {
+        return try all().updateAll(db, assignments)
+    }
+
+    /// Updates all records; returns the number of updated records.
+    ///
+    /// For example:
+    ///
+    ///     try dbQueue.write { db in
+    ///         // UPDATE player SET score = 0
+    ///         try Player.updateAll(db, Column("score") <- 0)
+    ///     }
+    ///
+    /// - parameter db: A database connection.
+    /// - returns: The number of updated rows
+    /// - throws: A DatabaseError is thrown whenever an SQLite error occurs.
+    @discardableResult
+    public static func updateAll(
+        _ db: Database,
+        _ assignment: ColumnAssignment,
+        _ otherAssignments: ColumnAssignment...)
+        throws -> Int
+    {
+        return try updateAll(db, [assignment] + otherAssignments)
+    }
 }
 
 extension MutablePersistableRecord {