SQLite 新增列

/// 已创建的表新增列
/// - Parameters:
///   - table: 目标table，即要添加的列所在的table
///   - coluName: 列名
///   - column: 列名表达式，例如“Expression<Int>("coluName")”
 ///   - defaultValue: 列默认值
class func addColumn<V:Value>(table:Table,coluName:String,column:Expression<V>,defaultValue:V) {
        do {
            var isExist = false
            let expression = table.expression
            let colunmnNames = try YKSQLiteManager.shareInstance().database.prepare(expression.template,expression.bindings).columnNames
            for  colName in colunmnNames {
                if colName == coluName {
                    isExist = true
                    break
                }
            }
            
            if !isExist {
                do {
                    try YKSQLiteManager.shareInstance().database.run(table.addColumn(column, defaultValue:defaultValue))
                } catch {
                    print("addError")
                }
            }
        } catch {
            
        }
    }