Automatic DB and Table Creation Support

* Added ability to specify any name for the database
* Added a public openDB method with the ability to specify whether to copy the DB from resources (default) or to create a new DB
* Added support for checking that each table specified via SQLTable exists on first access and to automatically create the table structure if it doesn’t exist
* Added asserts to verify that the DB is open before any queries are run
* Minor code clean up in SQLTable
* Updated iOS sample project to include the new openDB() method call

Author: FahimF

Examples/OSX/Resources/Base.lproj/Main.storyboard

@@ -1,7 +1,8 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.Storyboard.XIB" version="3.0" toolsVersion="6198" systemVersion="14A297b" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" initialViewController="B8D-0N-5wS">
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.Storyboard.XIB" version="3.0" toolsVersion="11762" systemVersion="16D32" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" initialViewController="B8D-0N-5wS">
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="6198"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="11762"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <scenes>
         <!--Application-->
@@ -641,12 +642,12 @@
                         <outlet property="delegate" destination="Voe-Tx-rLC" id="PrD-fu-P6m"/>
                     </connections>
                 </application>
-                <customObject id="Voe-Tx-rLC" customClass="AppDelegate" customModuleProvider="target"/>
+                <customObject id="Voe-Tx-rLC" customClass="AppDelegate" customModule="SQLiteDB_OSX" customModuleProvider="target"/>
                 <customObject id="Ady-hI-5gd" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
             </objects>
             <point key="canvasLocation" x="75" y="0.0"/>
         </scene>
-        <!--Window Controller - Window-->
+        <!--Window Controller-->
         <scene sceneID="R2V-B0-nI4">
             <objects>
                 <windowController id="B8D-0N-5wS" sceneMemberID="viewController">
@@ -667,7 +668,7 @@
         <!--View Controller-->
         <scene sceneID="hIz-AP-VOD">
             <objects>
-                <viewController id="XfG-lQ-9wD" customClass="ViewController" customModuleProvider="target" sceneMemberID="viewController">
+                <viewController id="XfG-lQ-9wD" customClass="ViewController" customModule="SQLiteDB_OSX" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" id="m2S-Jp-Qdl">
                         <rect key="frame" x="0.0" y="0.0" width="480" height="270"/>
                         <autoresizingMask key="autoresizingMask"/>

Examples/iOS/Source/AppDelegate.swift

@@ -9,12 +9,13 @@
 import UIKit
 
 @UIApplicationMain
-class AppDelegate: UIResponder, UIApplicationDelegate {
+class AppDelegate:UIResponder, UIApplicationDelegate {
 
 	var window: UIWindow?
 	let db = SQLiteDB.shared
 
 	func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
+		_ = db.openDB(copyFile:false)
 		return true
 	}
 

SQLTable.swift

@@ -15,6 +15,7 @@
 @objc(SQLTable)
 class SQLTable:NSObject {
 	private var table = ""
+	private static var verified = [String:Bool]()
 
 	private static var table:String {
 		let cls = "\(classForCoder())".lowercased()
@@ -30,6 +31,32 @@ class SQLTable:NSObject {
 		let ndx = cls.characters.index(before:cls.endIndex)
 		let tnm = cls.hasSuffix("y") ? cls.substring(to:ndx) + "ies" : cls + "s"
 		self.table = tnm
+		let verified = SQLTable.verified[table]
+		if verified == nil || !verified! {
+			// Verify that the table exists in DB
+			let db = SQLiteDB.shared
+			var sql = "SELECT name FROM sqlite_master WHERE type='table' AND name='\(table)'"
+			let cnt = db.query(sql:sql).count
+			if cnt == 1 {
+				// Table exists, proceed
+				SQLTable.verified[table] = true
+			} else if cnt == 0 {
+				// Table does not exist, create it
+				sql = "CREATE TABLE IF NOT EXISTS \(table) ("
+				// Columns
+				let cols = values()
+				sql += getColumnSQL(columns:cols)
+				// Close query
+				sql += ")"
+				let rc = db.execute(sql:sql)
+				if rc == 0 {
+					assert(false, "Error creating table - \(table) with SQL: \(sql)")
+				}
+				SQLTable.verified[table] = true
+			} else {
+				assert(false, "Got more than one table in DB with same name! Count: \(cnt) for \(table)")
+			}
+		}
 	}
 
 	// MARK:- Table property management
@@ -251,31 +278,12 @@ class SQLTable:NSObject {
 				if ignoredKeys().contains(name) || name.hasSuffix(".storage") {
 					continue
 				}
-				res[name] = get(value:attr.value)
+				res[name] = attr.value
 			}
 		}
 		return res
 	}
 
-	private func get(value:Any) -> Any {
-		if value is String {
-			return value as! String
-		} else if value is Int {
-			return value as! Int
-		} else if value is Float {
-			return value as! Float
-		} else if value is Double {
-			return value as! Double
-		} else if value is Bool {
-			return value as! Bool
-		} else if value is Date {
-			return value as! Date
-		} else if value is NSData {
-			return value as! NSData
-		}
-		return "nAn"
-	}
-	
 	private func getSQL(data:[String:Any], forInsert:Bool = true) -> (String, [Any]?) {
 		var sql = ""
 		var params:[Any]? = nil
@@ -329,4 +337,42 @@ class SQLTable:NSObject {
 //		NSLog("Final SQL: \(sql) with parameters: \(params)")
 		return (sql, params)
 	}
+	
+	private func getColumnSQL(columns:[String:Any]) -> String {
+		var sql = ""
+		for key in columns.keys {
+			let val = columns[key]!
+			var col = "'\(key)' "
+			if val is Int {
+				// Integers
+				col += "INTEGER"
+				if key == primaryKey() {
+					col += " PRIMARY KEY AUTOINCREMENT NOT NULL UNIQUE"
+				}
+			} else {
+				// Other values
+				if val is Float || val is Double {
+					col += "REAL"
+				} else if val is Bool {
+					col += "BOOLEAN"
+				} else if val is Date {
+					col += "DATE"
+				} else if val is NSData {
+					col += "BLOB"
+				} else {
+					// Default to text
+					col += "TEXT"
+				}
+				if key == primaryKey() {
+					col += " PRIMARY KEY NOT NULL UNIQUE"
+				}
+			}
+			if sql.isEmpty {
+				sql = col
+			} else {
+				sql += ", " + col
+			}
+		}
+		return sql
+	}
 }

SQLiteDB.swift

@@ -21,7 +21,7 @@ private let SQLITE_TRANSIENT = unsafeBitCast(-1, to:sqlite3_destructor_type.self
 // MARK:- SQLiteDB Class - Does all the work
 @objc(SQLiteDB)
 class SQLiteDB:NSObject {
-	let DB_NAME = "data.db"
+	var DB_NAME = "data.db"
 	let QUEUE_LABEL = "SQLiteDB"
 	static let shared = SQLiteDB()
 	private var db:OpaquePointer? = nil
@@ -31,61 +31,80 @@ class SQLiteDB:NSObject {
 
 	private override init() {
 		super.init()
+		// Set up essentials
+		queue = DispatchQueue(label:QUEUE_LABEL, attributes:[])
+		// You need to set the locale in order for the 24-hour date format to work correctly on devices where 24-hour format is turned off
+		fmt.locale = Locale(identifier:"en_US_POSIX")
+		fmt.timeZone = TimeZone(secondsFromGMT:0)
+		fmt.dateFormat = "yyyy-MM-dd HH:mm:ss"
+	}
+	
+	deinit {
+		closeDB()
+	}
+ 
+	override var description:String {
+		return "SQLiteDB: \(path)"
+	}
+	
+	// MARK:- Public Methods
+	func openDB(copyFile:Bool = true) -> Bool {
+		if db != nil {
+			closeDB()
+		}
 		// Set up for file operations
 		let fm = FileManager.default
 		// Get path to DB in Documents directory
 		var docDir = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)[0]
 		// If macOS, add app name to path since otherwise, DB could possibly interfere with another app using SQLiteDB
-#if os(OSX)
-		let info = Bundle.main.infoDictionary!
-		let appName = info["CFBundleName"] as! String
-		docDir = (docDir as NSString).appendingPathComponent(appName)
-		// Create folder if it does not exist
-		if !fm.fileExists(atPath:docDir) {
-			do {
-				try fm.createDirectory(atPath:docDir, withIntermediateDirectories:true, attributes:nil)
-			} catch {
-				assert(false, "SQLiteDB: Error creating DB directory: \(docDir) on macOS")
-				return
+		#if os(OSX)
+			let info = Bundle.main.infoDictionary!
+			let appName = info["CFBundleName"] as! String
+			docDir = (docDir as NSString).appendingPathComponent(appName)
+			// Create folder if it does not exist
+			if !fm.fileExists(atPath:docDir) {
+				do {
+					try fm.createDirectory(atPath:docDir, withIntermediateDirectories:true, attributes:nil)
+				} catch {
+					assert(false, "SQLiteDB: Error creating DB directory: \(docDir) on macOS")
+					return false
+				}
 			}
-		}
-#endif
+		#endif
 		let path = (docDir as NSString).appendingPathComponent(DB_NAME)
-		// Check if copy of DB is there in Documents directory
-		if !(fm.fileExists(atPath:path)) {
-			// The database does not exist, so copy to Documents directory
-			guard let rp = Bundle.main.resourcePath else { return }
+		// Check if DB is there in Documents directory
+		if !(fm.fileExists(atPath:path)) && copyFile {
+			// The database does not exist, so copy it
+			guard let rp = Bundle.main.resourcePath else { return false }
 			let from = (rp as NSString).appendingPathComponent(DB_NAME)
 			do {
 				try fm.copyItem(atPath:from, toPath:path)
 			} catch let error {
 				assert(false, "SQLiteDB: Failed to copy writable version of DB! Error - \(error.localizedDescription)")
-				return
+				return false
 			}
 		}
-		openDB(path:path)
-	}
-	
-	private init(path:String) {
-		super.init()
-		openDB(path:path)
-	}
-	
-	deinit {
-		closeDB()
-	}
- 
-	override var description:String {
-		return "SQLiteDB: \(path)"
+		// Open the DB
+		let cpath = path.cString(using:String.Encoding.utf8)
+		let error = sqlite3_open(cpath!, &db)
+		if error != SQLITE_OK {
+			// Open failed, close DB and fail
+			NSLog("SQLiteDB - failed to open DB!")
+			sqlite3_close(db)
+			return false
+		}
+		NSLog("SQLiteDB opened!")
+		return true
 	}
 
-	// MARK:- Public Methods
+	// Return an ISO-8601 date string
 	func dbDate(dt:Date) -> String {
 		return fmt.string(from:dt)
 	}
 
 	// Execute SQL with parameters and return result code
-	func execute(sql:String, parameters:[Any]?=nil)->Int {
+	func execute(sql:String, parameters:[Any]? = nil)->Int {
+		assert(db != nil, "Database has not been opened! Use the openDB() method before any DB queries.")
 		var result = 0
 		queue.sync {
 			if let stmt = self.prepare(sql:sql, params:parameters) {
@@ -96,7 +115,8 @@ class SQLiteDB:NSObject {
 	}
 
 	// Run SQL query with parameters
-	func query(sql:String, parameters:[Any]?=nil)->[[String:Any]] {
+	func query(sql:String, parameters:[Any]? = nil)->[[String:Any]] {
+		assert(db != nil, "Database has not been opened! Use the openDB() method before any DB queries.")
 		var rows = [[String:Any]]()
 		queue.sync {
 			if let stmt = self.prepare(sql:sql, params:parameters) {
@@ -108,6 +128,7 @@ class SQLiteDB:NSObject {
 
 	// Versioning
 	func getDBVersion() -> Int {
+		assert(db != nil, "Database has not been opened! Use the openDB() method before any DB queries.")
 		var version = 0
 		let arr = query(sql:"PRAGMA user_version")
 		if arr.count == 1 {
@@ -118,34 +139,16 @@ class SQLiteDB:NSObject {
 
 	// Sets the 'user_version' value, a user-defined version number for the database. This is useful for managing migrations.
 	func set(version:Int) {
+		assert(db != nil, "Database has not been opened! Use the openDB() method before any DB queries.")
 		_ = execute(sql:"PRAGMA user_version=\(version)")
 	}
 
 	// MARK:- Private Methods
-	private func openDB(path:String) {
-		// Set up essentials
-		queue = DispatchQueue(label:QUEUE_LABEL, attributes:[])
-		// You need to set the locale in order for the 24-hour date format to work correctly on devices where 24-hour format is turned off
-		fmt.locale = Locale(identifier:"en_US_POSIX")
-		fmt.timeZone = TimeZone(secondsFromGMT:0)
-		fmt.dateFormat = "yyyy-MM-dd HH:mm:ss"
-		// Open the DB
-		let cpath = path.cString(using: String.Encoding.utf8)
-		let error = sqlite3_open(cpath!, &db)
-		if error != SQLITE_OK {
-			// Open failed, close DB and fail
-			NSLog("SQLiteDB - failed to open DB!")
-			sqlite3_close(db)
-			return
-		}
-		NSLog("SQLiteDB opened!")
-	}
-	
 	private func closeDB() {
 		if db != nil {
 			// Get launch count value
 			let ud = UserDefaults.standard
-			var launchCount = ud.integer(forKey: "LaunchCount")
+			var launchCount = ud.integer(forKey:"LaunchCount")
 			launchCount -= 1
 			NSLog("SQLiteDB - Launch count \(launchCount)")
 			var clean = false
@@ -167,6 +170,7 @@ class SQLiteDB:NSObject {
 				NSLog("SQLiteDB - Error cleaning DB")
 			}
 			sqlite3_close(db)
+			self.db = nil
 		}
 	}
 
@@ -188,9 +192,9 @@ class SQLiteDB:NSObject {
 		if params != nil {
 			// Validate parameters
 			let cntParams = sqlite3_bind_parameter_count(stmt)
-			let cnt = CInt(params!.count)
-			if cntParams != cnt {
-				let msg = "SQLiteDB - failed to bind parameters, counts did not match. SQL: \(sql), Parameters: \(params)"
+			let cnt = params!.count
+			if cntParams != CInt(cnt) {
+				let msg = "SQLiteDB - failed to bind parameters, counts did not match. SQL: \(sql), Parameters: \(params!)"
 				NSLog(msg)
 				return nil
 			}
@@ -220,7 +224,7 @@ class SQLiteDB:NSObject {
 				if flag != SQLITE_OK {
 					sqlite3_finalize(stmt)
 					if let error = String(validatingUTF8:sqlite3_errmsg(self.db)) {
-						let msg = "SQLiteDB - failed to bind for SQL: \(sql), Parameters: \(params), Index: \(ndx) Error: \(error)"
+						let msg = "SQLiteDB - failed to bind for SQL: \(sql), Parameters: \(params!), Index: \(ndx) Error: \(error)"
 						NSLog(msg)
 					}
 					return nil