此文只是讲解一下 ios下sqlite3的最基本用法（创建表、增、删、改、查）的功能。

创DB管理类

import UIKit
import SQLite3

class SQManger: NSObject {
var db:OpaquePointer? = nil
static let instance = SQManger()
class func shareInstence() -> SQManger {
    return instance
}

func openDB() -> Bool {
    let filePath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).last!
    print(filePath)
    let file = filePath + "/test.sqlite"
    let cfile = file.cString(using: String.Encoding.utf8)
    let state = sqlite3_open(cfile,&db)
    if state != SQLITE_OK{
        print("打开数据库失败")
        return false
    }
    //创建表
    return creatTable()
}

func creatTable() -> Bool {
    let sql = "CREATE TABLE IF NOT EXISTS 't_student' ('id' integer NOT NULL PRIMARY KEY AUTOINCREMENT,'name' text,'age' integer );"
    return execSql(sql: sql)
}

func execSql(sql:String) -> Bool {
    let csql = sql.cString(using: String.Encoding.utf8)
    return sqlite3_exec(db, csql, nil, nil, nil) == SQLITE_OK
}

func updataData(sql:String) -> Bool {
   let csql = (sql.cString(using: String.Encoding.utf8))!
    if sqlite3_exec(db,csql, nil, nil, nil) != SQLITE_OK {
        return false
    }
    return true
}
func deleteData(sql:String) {
   
    if SQManger.shareInstence().execSql(sql: sql) {
        print("删除成功")
    }else{
         print("删除失败")
    }
}
func querySql(sql:String) -> [Any]? {
    var stmt:OpaquePointer? = nil
    let csql = (sql.cString(using: String.Encoding.utf8))!
    
    if sqlite3_prepare(db, csql, -1, &stmt, nil) != SQLITE_OK {
        print("未准备好")
        return nil
    }
    //准备好
    var tempArr = [Any]()
    
    while sqlite3_step(stmt) == SQLITE_ROW {
      
       let name = String.init(cString: sqlite3_column_text(stmt, 0)!)
       let age = String.init(cString: sqlite3_column_text(stmt, 1)!)
   
        let model = Student.init(name: name, age: Int(age) ?? 0)
        tempArr.append(model)
    }
    return tempArr
}

func querySql(kdyWords:String) -> [Any]? {
    var stmt:OpaquePointer? = nil
    let sql = "SELECT name,age FROM t_student WHERE name LIKE '%\(kdyWords)%' OR age LIKE '%\(kdyWords)%';"
    let csql = (sql.cString(using: String.Encoding.utf8))!
    
    if sqlite3_prepare(db, csql, -1, &stmt, nil) != SQLITE_OK {
        print("未准备好")
        return nil
    }
    //准备好
    var tempArr = [Any]()
    
    while sqlite3_step(stmt) == SQLITE_ROW {
        
        let name = String.init(cString: sqlite3_column_text(stmt, 0)!)
        let age = String.init(cString: sqlite3_column_text(stmt, 1)!)
        
        let model = Student.init(name: name, age: Int(age) ?? 0)
        tempArr.append(model)
    }
    return tempArr
    }
}

打开数据库（如果不存在表则会新建表）

   //保证数据库长链接，启动即打开数据库
    if  SQManger.shareInstence().openDB() {
        print("数据库打开成功")
    }

增

//增
@IBAction func add(_ sender: UIButton) {
    //模拟新增100条数据
    for i in 0..<100 {
        let stu = Student(name: "张三\(i)", age: Int(arc4random() % 100))
        stu.insert()
    }
}

删

  //删出名字叫张三3的数据 （删除所有数据）
@IBAction func deleteData(_ sender: UIButton) {
      // let deleSql = "DELETE FROM t_student WHERE name = '张三3';"
    let deleSql = "DELETE FROM t_student;"
    SQManger.shareInstence().deleteData(sql: deleSql)
    self.tableview.reloadData()
}

改

 @IBAction func modeification(_ sender: UIButton) {
    let sql = "UPDATE t_student SET name = '西门庆' WHERE age > 80;"//将年龄大于80的人的名字修改为 西门庆
    if  SQManger.shareInstence().updataData(sql: sql) {
        print("更新成功")
    }else{
        print("更新失败")
    }
}

查

 //查询所有数据
@IBAction func query(_ sender: UIButton) {
    let arr = Student.loadData()
    addData(arr: arr)
}

//根据关键字查询
  func queryOfKeyWord(ksyWord:String) {
      let arr = SQManger.shareInstence().querySql(kdyWords: searchText)
      addData(arr: arr)
  }

具体sq查询语句可以参考这篇文章