如何使用 GRDB 将项目添加到结构中但不在 Db table 中的数组中

Question

在 Db 的 My_Quotes table（参见下面的 MyQuotes 结构）中，我存储了从设备上的用户联系人中选择的联系人 ID。这样，如果联系人信息发生更改，ID 将保持不变。因此，我从 Db 中的 My_Quotes table 中提取 ContactID，并使用它通过 func get_ContactName_Org.

构建 ContactFullName、ContactFirst、ContactLast 和 ContactOrg

我遇到的问题是 ContactFullName、ContactFirst、ContactLast 和 ContactOrg（请参阅下面的 QuoteList 结构）不在 My_Quotes table 中。错误是：致命错误：无法从缺少的列 ContactFullName

中读取字符串

我理解错误，但将这些项目添加到 My_Quotes table 会导致许多其他问题。如何将这些项目插入到数组中？

        var theArray = [QuoteList]()

        do {
            try dbQueue_GRDB.read { db in
                for quotes in try QuoteList.fetchAll(db, sql: "SELECT * FROM My_Quotes ORDER BY QuoteID")
                {
                    let fullString = ModelData.get_ContactName_Org(contactID: quotes.ContactID).fullStaring
                    let first = ModelData.get_ContactName_Org(contactID: quotes.ContactID).firstName
                    let last = ModelData.get_ContactName_Org(contactID: quotes.ContactID).lastName
                    let org = ModelData.get_ContactName_Org(contactID: quotes.ContactID).clientOrg

                    theArray.append(QuoteList(QuoteID: quotes.QuoteID,
                                              Quote_Number: quotes.Quote_Number,
                                              Quote_Status: quotes.Quote_Status,
                                              ContactID: quotes.ContactID,
                                              ContactFullName: fullString, // This is not in the My_Quotes table
                                              ContactFirst: first, // This is not in the My_Quotes table
                                              ContactLast: last, // This is not in the My_Quotes table
                                              ContactOrg: org, // This is not in the My_Quotes table
                                              Inv_ID: quotes.Inv_ID,
                                              Locked_Bool: quotes.Locked_Bool))
                }
            }
        } catch {
            print("Couldn't populate the quote list! \(error)")
        }


    static func get_ContactName_Org(contactID: String) -> (firstName: String, lastName: String, clientOrg: String, fullStaring: String)
    {
        let store = CNContactStore()
        var theName = CNContact()
        var theStaring: String = ""
        var firstName: String = ""
        var lastName: String = ""
        var clientOrg: String = ""
        
        do {
            theName = try store.unifiedContact(withIdentifier: contactID, keysToFetch: [CNContactFormatter.descriptorForRequiredKeys(for: .fullName)])
            
        } catch {
            print("Fetching contact data failed: \(error)")
        }
        
        firstName = theName.givenName
        lastName = theName.familyName
        clientOrg = theName.organizationName
        
        theStaring = theName.organizationName == "" ? theName.givenName + " " + theName.familyName : theName.givenName + " " + theName.familyName + ", " + theName.organizationName
        
        return (firstName,lastName,clientOrg,theStaring)
    }
    

struct QuoteList: Codable, FetchableRecord
{
    let QuoteID: Int64
    var Quote_Number: String
    var Quote_Status: String
    var ContactID: String
    var ContactFullName: String // This is not in the My_Quotes table
    var ContactFirst: String // This is not in the My_Quotes table
    var ContactLast: String // This is not in the My_Quotes table
    var ContactOrg: String // This is not in the My_Quotes table
    var Inv_ID: Int64?
    var Locked_Bool: String
}


struct MyQuotes: Codable, FetchableRecord
{
    let QuoteID: Int64
    var Quote_Number: String
    var Quote_Date: String
    var Quote_Status: String
    var NumOf_People: String?
    var Event_Venue: String?
    var Routine_ID: Int64?
    var Routine_Price: Double?
    var Quote_Deposit: Double?
    var Deposit_Date: String?
    var Age_Range: String?
    var Lodging_Exp: Double?
    var Gas_Exp: Double?
    var Meals_Exp: Double?
    var Miscel_Exp: Double?
    var Airfare_Exp: Double?
    var Show_Start: String?
    var Show_End: String?
    var Show_Date: String?
    var Notes_Exp: String?
    var ContactID: String
    var Quote_Rejection: String?
    var Inv_ID: Int64?
    var Quote_Discount: Int?
    var Locked_Bool: String
}

Answer 1

首先，没有QuoteList采纳FetchableRecord。为什么？因为数据库行没有包含足够的信息来构建 QuoteList。 FetchableRecord 带有一个 init(row: Row) 初始值设定项，无法正确实现，正如致命错误告诉您的那样。让 QuoteList 采用 FetchableRecord 并向其提供不包含足够信息的数据库行是程序员的错误。

FetchableRecord是一个协议，自带方便的抓取方式，这就是你被它吸引的原因。但现在很明显 QuoteList 需要其他东西，是时候以不同的方式获取。

一种可能的技术是获取原始数据库行：

// Instead of:
// for quotes in try QuoteList.fetchAll(db, sql: "SELECT * FROM My_Quotes ORDER BY QuoteID")
for rows in try Row.fetchAll(db, sql: "SELECT * FROM My_Quotes ORDER BY QuoteID") {
    let fullString = ModelData.get_ContactName_Org(contactID: quotes.ContactID).fullStaring
    let first = ModelData.get_ContactName_Org(contactID: quotes.ContactID).firstName
    let last = ModelData.get_ContactName_Org(contactID: quotes.ContactID).lastName
    let org = ModelData.get_ContactName_Org(contactID: quotes.ContactID).clientOrg
    
    let quoteList = QuoteList(
        QuoteID: row["QuoteID"],
        Quote_Number: row["Quote_Number"],
        Quote_Status: row["Quote_Status"],
        ContactID: row["ContactID"],
        ContactFullName: fullString,
        ContactFirst: first,
        ContactLast: last,
        ContactOrg: org,
        Inv_ID: row["Inv_ID"],
        Locked_Bool: row["Locked_Bool"])
    
    theArray.append(quoteList)
}

另一种技术是定义一个实际可获取的模型：

struct PartialQuoteList: Codable, FetchableRecord
{
    let QuoteID: Int64
    var Quote_Number: String
    var Quote_Status: String
    var ContactID: String
    var Inv_ID: Int64?
    var Locked_Bool: String
}
for partial in try PartialQuoteList.fetchAll(db, sql: "SELECT * FROM My_Quotes ORDER BY QuoteID") {
    let fullString = ModelData.get_ContactName_Org(contactID: quotes.ContactID).fullStaring
    let first = ModelData.get_ContactName_Org(contactID: quotes.ContactID).firstName
    let last = ModelData.get_ContactName_Org(contactID: quotes.ContactID).lastName
    let org = ModelData.get_ContactName_Org(contactID: quotes.ContactID).clientOrg
    
    let quoteList = QuoteList(
        QuoteID: partial.QuoteID,
        Quote_Number: partial.Quote_Number,
        Quote_Status: partial.Quote_Status,
        ContactID: partial.ContactID,
        ContactFullName: fullString,
        ContactFirst: first,
        ContactLast: last,
        ContactOrg: org,
        Inv_ID: partial.Inv_ID
        Locked_Bool: partial.Locked_Bool)
    
    theArray.append(quoteList)
}

如何使用 GRDB 将项目添加到结构中但不在 Db table 中的数组中

How to add items into an array that are in the struct but not in the Db table using GRDB

arrays

xcode

ios

swift

grdb