f69ffUJ0

1import Foundation
2
3enum SQLite3Error : Error {
4    case connectionError(String)
5    case queryError(String)
6    case valueError(String)
7    case otherError(String)
8}
9
10class SQLite3Conn {
11    var stmt: OpaquePointer? = nil
12    var db: OpaquePointer? = nil
13    
14    init?() {
15        var needsSetup = false
16        let path = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
17                    .last!.appendingPathComponent("data.db").path
18        if !FileManager.default.fileExists(atPath: path) {
19            print("no database file. setup.")
20            needsSetup = true
21            
22        }
23        /*
24         func sqlite3_open(_ filename: UnsafePointer<Int8>!, _ ppDb: UnsafeMutablePointer<OpaquePointer?>!) -> Int32
25         */
26        if sqlite3_open(path, &db) != SQLITE_OK {
27            return nil
28        }
29        if needsSetup {
30            let query = "CREATE TABLE IF NOT EXISTS test ( num INT, text TEXT );"
31            do {
32                try prepare(query: query){ () -> Void in
33                    if sqlite3_step(stmt) != SQLITE_DONE {
34                        throw SQLite3Error.valueError("Fail to create table")
35                    }
36                }
37
38            } catch {
39                print("Error")
40                return nil
41            }
42        }
43    }
44    
45    deinit {
46        if let db = db {
47            sqlite3_close(db)
48        }
49    }
50    
51    func prepare<ResultType>(query: String, _ body: () throws -> ResultType) throws -> ResultType {
52        /*
53         func sqlite3_prepare_v2(
54                 _ db: OpaquePointer!,
55                 _ zSql: UnsafePointer<Int8>!, 
56                 _ nByte: Int32, 
57                 _ ppStmt: UnsafeMutablePointer<OpaquePointer?>!, 
58                 _ pzTail: UnsafeMutablePointer<UnsafePointer<Int8>?>!
59         ) -> Int32
60         */
61        guard sqlite3_prepare_v2(db, query, -1, &stmt, nil) == SQLITE_OK
62            else { throw SQLite3Error.queryError("Fail to compile Query:\n\(query)")}
63        defer {sqlite3_finalize(stmt)}
64        let r = try body()
65        return r
66    }
67}
68
69extension SQLite3Conn {
70    func insert(num: Int32, text: String) {
71        let query = "INSERT INTO test (num, text) VALUES (?, ?)"
72        do {
73            try prepare(query: query){ () -> Void in
74                guard sqlite3_bind_int(stmt, 1, num) == SQLITE_OK else { throw SQLite3Error.valueError("can't bind num") }
75                guard sqlite3_bind_text(stmt, 2, text, -1, nil) == SQLITE_OK else {throw SQLite3Error.valueError("can't bind text")}
76                guard sqlite3_step(stmt) == SQLITE_DONE else {throw SQLite3Error.otherError("Fail to insert")}
77                print("ok")
78            }
79        } catch {
80            print("fail")
81        }
82    }
83}
84
85
86let d = SQLite3Conn()!
87d.insert(num: 2, text: "World")
88d.insert(num: 43, text: "TEST")
89d.insert(num:55, text: "Anna")