Question

我有两个桌子。 promote_student和Student。我想将数据从promote_student复制到str = "INSERT INTO [promote_student] SELECT * FROM [Student] WHERE [SrNo] = " & row.Cells("sr_no").Value & " AND [session] = " & from_session.Text & "" cmd = New OleDb.OleDbCommand(str, cn) da.SelectCommand = cmd da.Fill(ds, "promote_student")。

对于此任务，我编写了以下查询：

sr_no

此处from_session是唯一值，import * as sinon from 'sinon' import UserDetails from '../../src/model/UserDetails'; import * as ClassValidator from "class-validator"; import * as PasswordHash from 'password-hash'; let sandbox: sinon.SinonSandbox; describe('Model > LoginUserDetails', () => { let userDetailsLetralObject = { email: 'zia@g.com', password: 'Savanur1', roles: ['lecturer'], departments: ['ec'] }; const userDetails = new UserDetails(userDetailsLetralObject.email, userDetailsLetralObject.password, userDetailsLetralObject.roles, userDetailsLetralObject.departments, false ); beforeEach(() => { sandbox = sinon.createSandbox(); }); afterEach(() => { sandbox.restore(); }); describe('constructor testing...', () => { test('With password hash', async (done) => { const passwordHashStub = sandbox.stub(PasswordHash, 'generate').returns('hashedPassword') console.log(PasswordHash.generate('mnop')) // Here it prints string 'hashedPassword' i.e returned buy passwordHashStub method let userDeatilsObj = await new UserDetails( userDetailsLetralObject.email, userDetailsLetralObject.password, userDetailsLetralObject.roles, userDetailsLetralObject.departments, true); expect(passwordHashStub.withArgs(userDetailsLetralObject.password).calledOnce).toBeTruthy() // This will check for not equal expect(userDeatilsObj).not.toEqual(userDetails) expect(userDeatilsObj.validatePassword('hashedPassword')).toBeTruthy() done(); }); }); });是'2018-2019'，但是此查询没有复制任何内容。我也没有任何错误。

Answer 1

在此查询中，如果不是，则您的promote_student表列和Student表列将相同。并且请不要连接您的SQL查询，请使用参数来保护Sql注入。您的查询如下：

public static void main(String[] args) {

        // Sample Strings to be subtituted
        String y = "/person/PATH_VARIABLE/address/PATH_VARIABLE";
        String y1 = "/person/PATH_VARIABLE/PATH_VARIABLE";

        // Tried this 
        //y = y.replaceAll("PATH_VARIABLE", "\\((.*?)\\)");
        //y1 = y1.replaceAll("PATH_VARIABLE", "\\((.*?)\\)");

        // Tried this one
        y = y.replaceAll("PATH_VARIABLE", "(?<=/)(.*?)(?=/?)");
        y1 = y1.replaceAll("PATH_VARIABLE", "(?<=/)(.*?)(?=/?)");

        // Sample input strings to match 
        String x = "/person/user.zian/address/123";
        String x1 = "/person/nhbb/bhbhb/ghyu";
        String x2 = "/person/nhbb/bhbhb";


        System.out.println(x.matches(y)); // returns true
        System.out.println(x1.matches(y)); // returns false
        System.out.println(x1.matches(y1)); // returns true but should return false
        System.out.println(x2.matches(y1)); // returns true


    }

Answer 2

如果要插入数据，则应呼叫vd <- merge(d, v, by="ID")。

我也不相信x <- vd[vd$place == "a",] hist(x$layer)是插入数据的最佳方法，尤其是当您有主键时。相反，您要指定要插入的列以及要从中选择的列。

我会强烈考虑使用参数来避免SQL注入。有关更多信息，请参见Bobby Tables。我使用cmd.ExecuteNonQuery()作为参数的占位符。使用SELECT * FROM [Student]时，请务必注意，重要的不是参数的名称而是参数的声明顺序。我指定了数据类型，因此请考虑使用OleDbParameter Constructor (String, OleDbType)添加参数。

最后，我还将考虑实施Using：

.NET Framework垃圾收集器（GC）处理托管资源，而无需您进行任何额外的编码。对于托管资源，您不需要使用模块。但是，您仍然可以使用Using块来强制处置托管资源，而不必等待垃圾回收器。

这是一些示例代码：

请注意，我不知道您的表结构，因此提供了一个示例。您将不得不更改列名称以适合

还要注意，我已经使用过OleDbCommand。您将要用数据库中使用的数据类型替换Using con As OleDbConnection = cn, cmd As New OleDbCommand("INSERT INTO [promote_student] (column1, column2, column3) SELECT column1, column2, column3 FROM [Student] WHERE [SrNo] = ? AND [session] = ?", con) con.Open() cmd.Parameters.Add("@srNo", OleDbType.[Type]).Value = row.Cells("sr_no").Value cmd.Parameters.Add("@session", OleDbType.[Type]).Value = from_session.Text cmd.ExecuteNonQuery() End Using。

无法使用SELECT语句插入数据

2 个答案: