这篇文章主要讲解了“Swift版的SQLite帮助类怎么创建”,文中的讲解内容简单清晰,易于学习与理解,下面请大家跟着小编的思路慢慢深入,一起来研究和学习“Swift版的SQLite帮助类怎么创建”吧!
SQLiteHelper
创建SQLiteHelper类
/// SQLite数据库处理帮助类
///
/// 此类中封装了关于SQLite数据库处理的业务函数
class SQLiteHelper
{
// 业务代码...}
单例
private static let instance = SQLiteHelper()/// 单例 全局的数据访问接口class var sharedInstance: SQLiteHelper
{return instance
}
全局变量
var db: COpaquePointer = nil
打开数据库
/// 打开数据库////// :param: dbName 数据库名称////// :returns: 返回 是否打开成功func openDatabase(dbName: String) -> Bool
{let path = dbName.documentPath()
println(path)return sqlite3_open(path, &db) == SQLITE_OK
}
创建示例数据表
/// 创建 T_Department 和 T_Employee 表////// :returns: 返回 是否创建成功func createTable() -> Bool
{
let sql = "CREATE TABLE \n" +"IF NOT EXISTS T_Department (\n" +"id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,\n" +"DepartmentNo CHAR(10) NOT NULL DEFAULT '',\n" +"Name CHAR(50) NOT NULL DEFAULT '' \n" +"); \n" +"CREATE TABLE IF NOT EXISTS T_Employee ( \n" +"'id' INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, \n" +
"'name' TEXT NOT NULL, \n" +
"'age' INTEGER NOT NULL, \n" +
"'department_id' INTEGER, \n" +
"CONSTRAINT 'FK_DEP_ID' FOREIGN KEY ('department_id') REFERENCES 'T_Department' ('id') \n" +
");"
// 返回结果
return execSql(sql)
}
执行INSERT、UPDATE、DELETE 语句
/// 执行INSERT、UPDATE、DELETE SQL语句////// :param: sql SQL语句////// :returns: 返回 是否执行成功func execSql(sql: String) -> Bool
{// 返回结果
return sqlite3_exec(db, sql.cStringUsingEncoding(NSUTF8StringEncoding)!, nil, nil, nil) == ITE_OK
}
执行SQL语句 返回结果数量
/// 执行SQL语句 返回结果数量////// :param: sql SQL语句////// :returns: 返回 结果func execCount(sql: String) -> Int
{let record = execRecordSet(sql)// 返回结果return (record[0] as! [AnyObject])[0] as! Int
}
执行返回单条记录
/// 执行返回单条记录////// :param: sql SQL语句////// :returns: 返回 单条记录func execRow(sql: String) -> [AnyObject]?
{let record = execRecordSet(sql)if record.count > 0{return (record[0] as! [AnyObject])
}else{return nil
}
}
执行 SQL 返回结果集合
/// 执行 SQL 返回结果集合////// :param: sql SQL语句////// :returns: 返回 查询的结果集func execRecordSet(sql: String) -> [AnyObject]
{var stmt: COpaquePointer = nilvar recordList = [AnyObject]()if sqlite3_prepare_v2(db, sql.cStringUsingEncoding(NSUTF8StringEncoding)!, -1, &stmt, nil) == TE_OK
{while sqlite3_step(stmt) == SQLITE_ROW
{
recordList.append(singleData(stmt)!)
}
}// 释放语句sqlite3_finalize(stmt)// 返回结果return recordList
}
执行一行数据
/// 执行一行数据////// :param: stmt 执行的语句////// :returns: 返回一行数据数组func singleData(stmt: COpaquePointer) -> [AnyObject]?
{var result = [AnyObject]()// 返回该表的列数let count = sqlite3_column_count(stmt)// #define SQLITE_INTEGER 1// #define SQLITE_FLOAT 2// #define SQLITE_BLOB 4// #define SQLITE_NULL 5// #ifdef SQLITE_TEXT// # undef SQLITE_TEXT// #else// # define SQLITE_TEXT 3// #endif// #define SQLITE3_TEXT 3for index in 0..<count
{let type = sqlite3_column_type(stmt, index)// 根据字段的类型,提取对应列的值switch type {case SQLITE_INTEGER:
result.append(Int(sqlite3_column_int64(stmt, index)))case SQLITE_FLOAT:
result.append(sqlite3_column_double(stmt, index))case SQLITE_NULL:
result.append(NSNull())case SQLITE_TEXT:let rrrrr: UnsafePointer<UInt8> = sqlite3_column_text(stmt, index)let chars = UnsafePointer<CChar>(sqlite3_column_text(stmt, index))let str = String(CString: chars, encoding: NSUTF8StringEncoding)!
result.append(str)case let type:
println("不支持的类型 \(type)")
}
}// 返回结果return result
}
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