reset after execute (#13)

Author: Alexander-Ignition

Playgrounds/README.playground/Contents.swift

@@ -39,7 +39,7 @@ try database.execute(sql)
  Insert new contacts Paul and John.
  */
 let insert = try database.prepare("INSERT INTO contacts (id, name) VALUES (?, ?);")
-try insert.bind(parameters: 1, "Paul").execute().reset()
+try insert.bind(parameters: 1, "Paul").execute()
 try insert.bind(parameters: 2, "John").execute()
 /*:
  ## Select
@@ -48,19 +48,20 @@ try insert.bind(parameters: 2, "John").execute()
  */
 struct Contact: Codable {
     let id: Int
-    let name: String
+    let name: String?
 }
 
 let select = try database.prepare("SELECT * FROM contacts;")
 let contacts = try select.array(Contact.self)
+print(contacts)
 /*:
  ## DataFrame
 
  The [DataFrame](https://developer.apple.com/documentation/tabulardata/dataframe) from the [TabularData](https://developer.apple.com/documentation/tabulardata) framework is supported.
 
  It can help to print the table.
  */
-let df = try database.prepare("SELECT * FROM contacts;").dataFrame()
+let df = try select.dataFrame()
 print(df)
 /*:
  ```

README.md

@@ -38,7 +38,7 @@ try database.execute(sql)
 Insert new contacts Paul and John.
 ```swift
 let insert = try database.prepare("INSERT INTO contacts (id, name) VALUES (?, ?);")
-try insert.bind(parameters: 1, "Paul").execute().reset()
+try insert.bind(parameters: 1, "Paul").execute()
 try insert.bind(parameters: 2, "John").execute()
 ```
 ## Select
@@ -47,19 +47,20 @@ Select all contacts from database.
 ```swift
 struct Contact: Codable {
     let id: Int
-    let name: String
+    let name: String?
 }
 
 let select = try database.prepare("SELECT * FROM contacts;")
 let contacts = try select.array(Contact.self)
+print(contacts)
 ```
 ## DataFrame
 
 The [DataFrame](https://developer.apple.com/documentation/tabulardata/dataframe) from the [TabularData](https://developer.apple.com/documentation/tabulardata) framework is supported.
 
 It can help to print the table.
 ```swift
-let df = try database.prepare("SELECT * FROM contacts;").dataFrame()
+let df = try select.dataFrame()
 print(df)
 ```
 ```

Sources/SQLyra/DataFrame.swift

@@ -41,6 +41,7 @@ extension PreparedStatement {
         }
         var df = DataFrame(columns: columns)
         var count = 0
+        defer { _reset() }
         while let row = try row() {
             df.appendEmptyRow()
             for index in (0..<columnCount) {

Sources/SQLyra/PreparedStatement.swift

@@ -33,7 +33,8 @@ public final class PreparedStatement: DatabaseHandle {
     /// - Throws: ``DatabaseError``
     @discardableResult
     public func execute() throws -> PreparedStatement {
-        try check(sqlite3_step(stmt), SQLITE_DONE)
+        defer { _reset() }
+        return try check(sqlite3_step(stmt), SQLITE_DONE)
     }
 
     /// Reset the prepared statement.
@@ -47,6 +48,11 @@ public final class PreparedStatement: DatabaseHandle {
     public func reset() throws -> PreparedStatement {
         try check(sqlite3_reset(stmt))
     }
+
+    /// clear error state and prepare for reuse
+    func _reset() {
+        sqlite3_reset(stmt)
+    }
 }
 
 // MARK: - Retrieving Statement SQL
@@ -176,6 +182,7 @@ extension PreparedStatement {
     }
 
     public func array<T>(_ type: T.Type, using decoder: RowDecoder) throws -> [T] where T: Decodable {
+        defer { _reset() }
         var array: [T] = []
         while let row = try row() {
             let value = try row.decode(type, using: decoder)

Tests/SQLyraTests/PreparedStatementTests.swift

@@ -8,7 +8,7 @@ struct Contact: Codable, Equatable, Sendable {
     let rating: Double?
     let image: Data?
 
-    static let table = "CREATE TABLE contacts (id INT, name TEXT, rating FLOAT, image BLOB);"
+    static let table = "CREATE TABLE contacts (id INT, name TEXT, rating REAL, image BLOB) STRICT;"
     static let insert = "INSERT INTO contacts (id, name, rating, image) VALUES (:id, :name, :rating, :image)"
 }
 
@@ -71,7 +71,7 @@ struct PreparedStatementTests {
     @Test func columns() throws {
         let insert = try db.prepare(Contact.insert)
 
-        try insert.bind(parameters: 5, "A", 2.0, .null).execute().reset()
+        try insert.bind(parameters: 5, "A", 2.0, .null).execute()
         try insert.bind(parameters: 6, "B", .null, .blob(Data("123".utf8))).execute()
 
         let select = try db.prepare("SELECT * FROM contacts;")
@@ -94,11 +94,37 @@ struct PreparedStatementTests {
         #expect(contracts == expected)
     }
 
+    @Test func decode() throws {
+        let insert = try db.prepare(Contact.insert)
+
+        try insert.bind(parameters: 5, "A", 2.0, .null).execute()
+        try insert.bind(parameters: 6, "B", .null, .blob(Data("123".utf8))).execute()
+
+        let select = try db.prepare("SELECT * FROM contacts;")
+        let contracts = try select.array(Contact.self)
+
+        let expected = [
+            Contact(id: 5, name: "A", rating: 2.0, image: nil),
+            Contact(id: 6, name: "B", rating: nil, image: Data("123".utf8)),
+        ]
+        #expect(contracts == expected)
+    }
+
+    @Test func execute() throws {
+        let insert = try db.prepare(Contact.insert)
+
+        try insert.bind(name: ":id", parameter: "invalid")
+        #expect(throws: DatabaseError.self) { try insert.execute() }
+
+        try insert.bind(name: ":id", parameter: 4)
+        #expect(throws: Never.self) { try insert.execute() }
+    }
+
     @available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
     @Test func dataFrame() throws {
         let insert = try db.prepare(Contact.insert)
 
-        try insert.bind(parameters: 5, "A").execute().reset()
+        try insert.bind(parameters: 5, "A").execute()
         try insert.bind(parameters: 6, "B").execute()
 
         let df = try db.prepare("SELECT * FROM contacts;").dataFrame()